Initial import of upstream's 1.3.1.upstream/1.3.1

42 files changed, 4326 insertions, 0 deletions

diff --git a/GudhUI/CMakeLists.txt b/GudhUI/CMakeLists.txt
new file mode 100644
index 00000000..a43294ea
--- /dev/null
+++ b/GudhUI/CMakeLists.txt
@@ -0,0 +1,68 @@
+cmake_minimum_required(VERSION 2.8)
+project(GudhUI)
+
+find_package(Qt4)
+find_package(QGLViewer)
+find_package(OpenGL)
+
+if ( CGAL_FOUND AND QT4_FOUND AND OPENGL_FOUND AND QGLVIEWER_FOUND )
+  set( QT_USE_QTXML    TRUE )
+  set( QT_USE_QTMAIN   TRUE )
+  set( QT_USE_QTSCRIPT  TRUE )
+  set( QT_USE_QTOPENGL  TRUE )
+  SET(Boost_USE_STATIC_LIBS ON)
+  SET(Boost_USE_MULTITHREAD OFF)
+
+  include(${QT_USE_FILE})
+
+  include_directories (${QGLVIEWER_INCLUDE_DIR})
+  include_directories(.)	
+ 
+  # qt : ui file, created wih Qt Designer ###############
+  set(CMAKE_CURRENT_BINARY_DIR "${CMAKE_CURRENT_SOURCE_DIR}/gui")
+  qt4_wrap_ui( uis 
+    gui/main_window.ui
+    gui/MenuEdgeContraction.ui
+    gui/KNearestNeighborsMenu.ui
+    gui/UniformNeighborsMenu.ui
+    gui/PersistenceMenu.ui
+  )	
+
+  set(CMAKE_CURRENT_BINARY_DIR "${CMAKE_CURRENT_SOURCE_DIR}/gui")
+  qt4_automoc(
+    gui/MainWindow.cpp
+    gui/Menu_k_nearest_neighbors.cpp
+    gui/Menu_uniform_neighbors.cpp
+    gui/Menu_edge_contraction.cpp
+    gui/Menu_persistence.cpp    
+  )
+	
+  set(CMAKE_CURRENT_BINARY_DIR "${CMAKE_CURRENT_SOURCE_DIR}/view") 
+  qt4_automoc(view/Viewer_instructor.cpp		
+    view/Viewer.cpp
+  )	
+  #####################################################################
+
+  add_executable  ( GudhUI 
+    gui/gudhui.cpp
+    gui/MainWindow.cpp
+    gui/Menu_k_nearest_neighbors.cpp	
+    gui/Menu_uniform_neighbors.cpp
+    gui/Menu_edge_contraction.cpp  
+    gui/Menu_persistence.cpp
+    view/Viewer_instructor.cpp				
+    view/Viewer.cpp
+    ${uis}  
+  )	
+	
+  target_link_libraries( GudhUI ${QT_LIBRARIES} ${QGLVIEWER_LIBRARIES} )
+  target_link_libraries( GudhUI ${OPENGL_gl_LIBRARY} ${OPENGL_glu_LIBRARY} )	
+if (TBB_FOUND)
+  target_link_libraries( GudhUI ${TBB_LIBRARIES})
+endif()
+
+###############################################################################
+
+else()
+  message(STATUS "NOTICE: GudhUI requires CGAL, the QGLViewer, OpenGL and Qt4, and will not be compiled.")
+endif()
diff --git a/GudhUI/gui/KNearestNeighborsMenu.ui b/GudhUI/gui/KNearestNeighborsMenu.ui
new file mode 100644
index 00000000..472db48b
--- /dev/null
+++ b/GudhUI/gui/KNearestNeighborsMenu.ui
@@ -0,0 +1,150 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>KNearestNeighborsMenu</class>
+ <widget class="QDialog" name="KNearestNeighborsMenu">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>298</width>
+    <height>209</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>k-nearest neighbors</string>
+  </property>
+  <widget class="QDialogButtonBox" name="buttonBox">
+   <property name="geometry">
+    <rect>
+     <x>50</x>
+     <y>160</y>
+     <width>171</width>
+     <height>32</height>
+    </rect>
+   </property>
+   <property name="orientation">
+    <enum>Qt::Horizontal</enum>
+   </property>
+   <property name="standardButtons">
+    <set>QDialogButtonBox::Cancel|QDialogButtonBox::Ok</set>
+   </property>
+  </widget>
+  <widget class="QWidget" name="formLayoutWidget">
+   <property name="geometry">
+    <rect>
+     <x>30</x>
+     <y>10</y>
+     <width>229</width>
+     <height>84</height>
+    </rect>
+   </property>
+   <layout class="QFormLayout" name="formLayout_2">
+    <property name="fieldGrowthPolicy">
+     <enum>QFormLayout::AllNonFixedFieldsGrow</enum>
+    </property>
+    <item row="0" column="0">
+     <widget class="QLabel" name="label">
+      <property name="text">
+       <string>k </string>
+      </property>
+     </widget>
+    </item>
+    <item row="0" column="1">
+     <widget class="QSpinBox" name="spinBoxK">
+      <property name="maximum">
+       <number>10000000</number>
+      </property>
+      <property name="value">
+       <number>0</number>
+      </property>
+     </widget>
+    </item>
+    <item row="1" column="0">
+     <widget class="QLabel" name="label_2">
+      <property name="text">
+       <string>Metric</string>
+      </property>
+     </widget>
+    </item>
+    <item row="1" column="1">
+     <widget class="QComboBox" name="comboBoxMetric">
+      <item>
+       <property name="text">
+        <string>Ambient</string>
+       </property>
+      </item>
+      <item>
+       <property name="text">
+        <string>Reduced Space</string>
+       </property>
+      </item>
+     </widget>
+    </item>
+   </layout>
+  </widget>
+  <widget class="QWidget" name="gridLayoutWidget">
+   <property name="geometry">
+    <rect>
+     <x>30</x>
+     <y>110</y>
+     <width>250</width>
+     <height>40</height>
+    </rect>
+   </property>
+   <layout class="QGridLayout" name="gridLayout">
+    <item row="0" column="1">
+     <widget class="QPushButton" name="pushButtonCompute">
+      <property name="text">
+       <string>Compute</string>
+      </property>
+     </widget>
+    </item>
+    <item row="0" column="0">
+     <widget class="QCheckBox" name="checkBoxAutoUpdate">
+      <property name="text">
+       <string>auto update</string>
+      </property>
+      <property name="checked">
+       <bool>true</bool>
+      </property>
+     </widget>
+    </item>
+   </layout>
+  </widget>
+ </widget>
+ <resources/>
+ <connections>
+  <connection>
+   <sender>buttonBox</sender>
+   <signal>accepted()</signal>
+   <receiver>KNearestNeighborsMenu</receiver>
+   <slot>accept()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>248</x>
+     <y>254</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>157</x>
+     <y>274</y>
+    </hint>
+   </hints>
+  </connection>
+  <connection>
+   <sender>buttonBox</sender>
+   <signal>rejected()</signal>
+   <receiver>KNearestNeighborsMenu</receiver>
+   <slot>reject()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>316</x>
+     <y>260</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>286</x>
+     <y>274</y>
+    </hint>
+   </hints>
+  </connection>
+ </connections>
+</ui>
diff --git a/GudhUI/gui/MainWindow.cpp b/GudhUI/gui/MainWindow.cpp
new file mode 100644
index 00000000..779ccd33
--- /dev/null
+++ b/GudhUI/gui/MainWindow.cpp
@@ -0,0 +1,299 @@
+/*    This file is part of the Gudhi Library. The Gudhi library
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "MainWindow.h"
+
+#include <QWidget>
+#include <QInputDialog>
+#include <QFileDialog>
+
+#include <fenv.h>
+
+#include "gui/Menu_k_nearest_neighbors.h"
+#include "gui/Menu_uniform_neighbors.h"
+#include "gui/Menu_edge_contraction.h"
+#include "gui/Menu_persistence.h"
+
+MainWindow::MainWindow(QWidget* parent) :
+    menu_k_nearest_neighbors_(new Menu_k_nearest_neighbors(this)),
+    menu_uniform_neighbors_(new Menu_uniform_neighbors(this)),
+    menu_edge_contraction_(new Menu_edge_contraction(this, model_)),
+    menu_persistence_(new Menu_persistence(this)) {
+  // #ifndef NDEBUG // catch nan
+  // feenableexcept(FE_DIVBYZERO | FE_INVALID | FE_OVERFLOW);
+  // #endif
+
+  setupUi(this);
+
+  viewer_instructor_ = new Viewer_instructor(
+                                             this,
+                                             this->viewer,
+                                             model_.complex_);
+
+  connectActions();
+
+  update_view();
+}
+
+void
+MainWindow::closeEvent(QCloseEvent *event) {
+  exit(0);
+}
+
+void
+MainWindow::connectActions() {
+  QObject::connect(this->actionLoad_complex, SIGNAL(triggered()), this,
+                   SLOT(off_file_open()));
+  QObject::connect(this->actionLoad_points, SIGNAL(triggered()), this,
+                   SLOT(off_points_open()));
+  QObject::connect(this->actionSave_complex, SIGNAL(triggered()), this,
+                   SLOT(off_file_save()));
+  QObject::connect(this->actionSave_points, SIGNAL(triggered()), this,
+                   SLOT(off_points_save()));
+
+  QObject::connect(this->actionShow_graph_stats, SIGNAL(triggered()), this,
+                   SLOT(show_graph_stats()));
+  QObject::connect(this->actionShow_complex_stats, SIGNAL(triggered()), this,
+                   SLOT(show_complex_stats()));
+  QObject::connect(this->actionShow_complex_dimension, SIGNAL(triggered()), this,
+                   SLOT(show_complex_dimension()));
+
+  QObject::connect(this->actionUniform_proximity_graph, SIGNAL(triggered()), this,
+                   SLOT(build_rips_menu()));
+  QObject::connect(this->actionK_nearest_neighbors_graph, SIGNAL(triggered()), this,
+                   SLOT(build_k_nearest_neighbors_menu()));
+
+
+  QObject::connect(this->actionContract_edges, SIGNAL(triggered()), this,
+                   SLOT(contract_edge_menu()));
+
+  QObject::connect(this->actionCollapse_vertices, SIGNAL(triggered()), this,
+                   SLOT(collapse_vertices()));
+
+  QObject::connect(this->actionCollapse_edges, SIGNAL(triggered()), this,
+                   SLOT(collapse_edges()));
+
+  QObject::connect(this->actionNoise, SIGNAL(triggered()), this,
+                   SLOT(uniform_noise()));
+  QObject::connect(this->actionLloyd, SIGNAL(triggered()), this,
+                   SLOT(lloyd()));
+
+
+  // view
+  QObject::connect(this->actionPoints, SIGNAL(triggered()), this->viewer_instructor_,
+                   SLOT(change_draw_vertices()));
+  QObject::connect(this->actionEdges, SIGNAL(triggered()), this->viewer_instructor_,
+                   SLOT(change_draw_edges()));
+  QObject::connect(this->actionTriangles, SIGNAL(triggered()), this->viewer_instructor_,
+                   SLOT(change_draw_triangles()));
+
+  // topology
+  QObject::connect(this->actionShow_homology_group, SIGNAL(triggered()), this,
+                   SLOT(show_homology_group()));
+  QObject::connect(this->actionEuler_characteristic, SIGNAL(triggered()), this,
+                   SLOT(show_euler_characteristic()));
+  QObject::connect(this->actionPersistence, SIGNAL(triggered()), this,
+                   SLOT(persistence_menu()));
+  QObject::connect(this->actionEstimate_topological_changes, SIGNAL(triggered()), this,
+                   SLOT(critical_points_menu()));
+  QObject::connect(this->actionIs_manifold, SIGNAL(triggered()), this,
+                   SLOT(is_manifold_menu()));
+
+
+  QObject::connect(this, SIGNAL(sceneChanged()), this->viewer_instructor_,
+                   SLOT(sceneChanged()));
+}
+
+void
+MainWindow::init_view() const {
+  viewer_instructor_->initialize_bounding_box();
+  viewer_instructor_->show_entire_scene();
+  update_view();
+}
+
+void
+MainWindow::update_view() const {
+  emit(sceneChanged());
+}
+
+/**
+ * open a file chooser to choose an off to load
+ */
+void
+MainWindow::off_file_open() {
+  QString fileName = QFileDialog::getOpenFileName(this, tr("Open off File"),
+                                                  "~/", tr("off files (*.off)"));
+  if (!fileName.isEmpty()) {
+    model_.off_file_open(fileName.toStdString());
+    init_view();
+  }
+}
+
+void
+MainWindow::off_points_open() {
+  QString fileName = QFileDialog::getOpenFileName(this, tr("Open points in a off file"),
+                                                  "~/", tr("off files (*.off)"));
+  if (!fileName.isEmpty()) {
+    model_.off_points_open(fileName.toStdString());
+    init_view();
+  }
+}
+
+/**
+ * open a file chooser to choose an off to save
+ */
+void
+MainWindow::off_file_save() {
+  QString fileName = QFileDialog::getOpenFileName(this, tr("Save to off File"),
+                                                  "~/", tr("off files (*.off)"));
+  if (!fileName.isEmpty()) {
+    model_.off_file_save(fileName.toStdString());
+  }
+}
+
+/**
+ * open a file chooser to choose an off to save
+ */
+void
+MainWindow::off_points_save() {
+  QString fileName = QFileDialog::getOpenFileName(this, tr("Save to off File"),
+                                                  "~/", tr("off files (*.off)"));
+  if (!fileName.isEmpty()) {
+    model_.off_points_save(fileName.toStdString());
+  }
+}
+
+void
+MainWindow::show_graph_stats() {
+  model_.show_graph_stats();
+}
+
+void
+MainWindow::show_complex_stats() {
+  model_.show_complex_stats();
+}
+
+void
+MainWindow::show_complex_dimension() {
+  model_.show_complex_dimension();
+}
+
+void
+MainWindow::build_rips_menu() {
+  menu_uniform_neighbors_->show();
+}
+
+void
+MainWindow::build_rips(double alpha) {
+  model_.build_rips(alpha);
+  update_view();
+}
+
+void
+MainWindow::build_k_nearest_neighbors_menu() {
+  menu_k_nearest_neighbors_->show();
+}
+
+void
+MainWindow::build_k_nearest_neighbors(unsigned k) {
+  model_.build_k_nearest_neighbors(k);
+  update_view();
+}
+
+void
+MainWindow::contract_edge_menu() {
+  menu_edge_contraction_->show();
+}
+
+void
+MainWindow::contract_edges(unsigned num_collapses) {
+  std::cerr << "Collapse " << num_collapses << " vertices\n";
+  model_.contract_edges(num_collapses);
+  update_view();
+}
+
+void
+MainWindow::collapse_edges() {
+  model_.collapse_edges(model_.num_edges());
+  update_view();
+}
+
+void
+MainWindow::collapse_vertices() {
+  std::cerr << "Collapse vertices edges\n";
+  model_.collapse_vertices(0);
+  update_view();
+}
+
+void
+MainWindow::uniform_noise() {
+  bool ok;
+  double amplitude = QInputDialog::getDouble(this, tr("Uniform noise"),
+                                             tr("Amplitude:"), 0, 0, 10000, 3, &ok);
+  srand(time(NULL));
+  if (ok)
+    model_.uniform_noise(amplitude);
+}
+
+void
+MainWindow::lloyd() {
+  // todo 1 ask lloyd parameters
+  model_.lloyd(0, 0);
+  update_view();
+}
+
+void
+MainWindow::show_homology_group() {
+  model_.show_homology_group();
+}
+
+void
+MainWindow::show_euler_characteristic() {
+  model_.show_euler_characteristic();
+}
+
+void
+MainWindow::persistence_menu() {
+  menu_persistence_->show();
+}
+
+void
+MainWindow::compute_persistence(int p, double threshold, int max_dim, double min_pers) {
+  model_.show_persistence(p, threshold, max_dim, min_pers);
+}
+
+void
+MainWindow::critical_points_menu() {
+  bool ok;
+  double max_length = QInputDialog::getDouble(this, tr("Maximal edge length for the Rips"),
+                                              tr("Maximal edge length:"), 0, 0, 10000, 3, &ok);
+  if (ok)
+    model_.show_critical_points(max_length);
+}
+
+void
+MainWindow::is_manifold_menu() {
+  model_.show_is_manifold();
+}
+
+
+#include "MainWindow.moc"
diff --git a/GudhUI/gui/MainWindow.h b/GudhUI/gui/MainWindow.h
new file mode 100644
index 00000000..c8c3fcf6
--- /dev/null
+++ b/GudhUI/gui/MainWindow.h
@@ -0,0 +1,118 @@
+/*    This file is part of the Gudhi Library. The Gudhi library
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef GUI_MAINWINDOW_H_
+#define GUI_MAINWINDOW_H_
+
+// Workaround for moc-qt4 not parsing boost headers
+#include <CGAL/config.h>
+
+#include <QMainWindow>
+#include "ui_main_window.h"
+#include "model/Model.h"
+#include "view/Viewer_instructor.h"
+
+
+class Menu_k_nearest_neighbors;
+class Menu_uniform_neighbors;
+class Menu_edge_contraction;
+class Menu_persistence;
+
+class MainWindow : public QMainWindow, public Ui::MainWindow {
+  Q_OBJECT
+
+ private:
+  Model model_;
+  Viewer_instructor* viewer_instructor_;
+  Menu_k_nearest_neighbors* menu_k_nearest_neighbors_;
+  Menu_uniform_neighbors* menu_uniform_neighbors_;
+  Menu_edge_contraction* menu_edge_contraction_;
+  Menu_persistence* menu_persistence_;
+
+ public:
+  MainWindow(QWidget* parent = 0);
+  void connectActions();
+
+  /**
+   * compute the bounding box and calls update view
+   */
+  void init_view() const;
+  void update_view() const;
+
+
+ protected:
+  void closeEvent(QCloseEvent *event);
+
+  void keyPressEvent(QKeyEvent *event) { }
+
+ public:
+ public slots:
+  /**
+   * open a file chooser to choose an off to load
+   */
+  void off_file_open();
+
+  void off_points_open();
+
+  /**
+   * open a file chooser to choose an off to save
+   */
+  void off_file_save();
+  void off_points_save();
+
+  void show_graph_stats();
+  void show_complex_stats();
+  void show_complex_dimension();
+
+
+  void build_rips_menu();
+  void build_rips(double alpha);
+  void build_k_nearest_neighbors_menu();
+  void build_k_nearest_neighbors(unsigned k);
+
+
+  void contract_edge_menu();
+  void contract_edges(unsigned num_collapses);
+
+
+  void collapse_vertices();
+  void collapse_edges();
+
+
+  void uniform_noise();
+  void lloyd();
+
+  void show_homology_group();
+  void show_euler_characteristic();
+  void persistence_menu();
+  void compute_persistence(int p, double threshold, int max_dim, double min_pers);
+  void critical_points_menu();
+  void is_manifold_menu();
+
+
+ public:
+ signals:
+  void sceneChanged() const;
+};
+
+
+#endif  // GUI_MAINWINDOW_H_
diff --git a/GudhUI/gui/MenuEdgeContraction.ui b/GudhUI/gui/MenuEdgeContraction.ui
new file mode 100644
index 00000000..b1696431
--- /dev/null
+++ b/GudhUI/gui/MenuEdgeContraction.ui
@@ -0,0 +1,118 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>MenuEdgeContraction</class>
+ <widget class="QDialog" name="MenuEdgeContraction">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>362</width>
+    <height>209</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>Edge contraction</string>
+  </property>
+  <layout class="QGridLayout" name="gridLayout">
+   <item row="5" column="2">
+    <widget class="QSpinBox" name="spinBox_nb_remaining_vertices">
+     <property name="minimum">
+      <number>1</number>
+     </property>
+     <property name="maximum">
+      <number>999999999</number>
+     </property>
+     <property name="value">
+      <number>1</number>
+     </property>
+    </widget>
+   </item>
+   <item row="7" column="2">
+    <widget class="QCheckBox" name="checkBox_link_condition">
+     <property name="enabled">
+      <bool>false</bool>
+     </property>
+     <property name="text">
+      <string>Link condition</string>
+     </property>
+     <property name="checked">
+      <bool>true</bool>
+     </property>
+    </widget>
+   </item>
+   <item row="3" column="2" alignment="Qt::AlignRight">
+    <widget class="QLabel" name="txt_nb_collapses">
+     <property name="text">
+      <string>1</string>
+     </property>
+    </widget>
+   </item>
+   <item row="6" column="0">
+    <widget class="QLabel" name="label">
+     <property name="text">
+      <string>Policy</string>
+     </property>
+    </widget>
+   </item>
+   <item row="6" column="2">
+    <widget class="QComboBox" name="m_simplificationMethod">
+     <item>
+      <property name="text">
+       <string>Length_midpoint</string>
+      </property>
+     </item>
+    </widget>
+   </item>
+   <item row="2" column="2" alignment="Qt::AlignRight">
+    <widget class="QLabel" name="txt_nb_vertices">
+     <property name="text">
+      <string>0</string>
+     </property>
+    </widget>
+   </item>
+   <item row="2" column="0">
+    <widget class="QLabel" name="label_5">
+     <property name="text">
+      <string>Number of vertices</string>
+     </property>
+    </widget>
+   </item>
+   <item row="3" column="0" colspan="2">
+    <widget class="QLabel" name="label_3">
+     <property name="text">
+      <string>Number of contractions</string>
+     </property>
+    </widget>
+   </item>
+   <item row="5" column="0" colspan="2">
+    <widget class="QLabel" name="label_4">
+     <property name="text">
+      <string>Number of vertices after </string>
+     </property>
+    </widget>
+   </item>
+   <item row="1" column="0">
+    <widget class="QSlider" name="horizontalSlider">
+     <property name="minimum">
+      <number>0</number>
+     </property>
+     <property name="maximum">
+      <number>100</number>
+     </property>
+     <property name="orientation">
+      <enum>Qt::Horizontal</enum>
+     </property>
+    </widget>
+   </item>
+   <item row="1" column="2">
+    <widget class="QPushButton" name="pushButton_collapse">
+     <property name="text">
+      <string>Perform collapse</string>
+     </property>
+    </widget>
+   </item>
+  </layout>
+ </widget>
+ <resources/>
+ <connections/>
+</ui>
diff --git a/GudhUI/gui/Menu_edge_contraction.cpp b/GudhUI/gui/Menu_edge_contraction.cpp
new file mode 100644
index 00000000..a679b0bf
--- /dev/null
+++ b/GudhUI/gui/Menu_edge_contraction.cpp
@@ -0,0 +1,97 @@
+/*    This file is part of the Gudhi Library. The Gudhi library
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef GUI_MENU_EDGE_CONTRACTION_CPP_
+#define GUI_MENU_EDGE_CONTRACTION_CPP_
+
+#include "Menu_edge_contraction.h"
+
+Menu_edge_contraction::Menu_edge_contraction(MainWindow* parent, const Model& model) :
+    parent_(parent), model_(model) {
+  setupUi(this);
+  connectActions(parent_);
+}
+
+void Menu_edge_contraction::connectActions(MainWindow* parent) {
+  QObject::connect(
+                   this->horizontalSlider,
+                   SIGNAL(valueChanged(int)),
+                   this,
+                   SLOT(slider_value_changed(int)));
+
+
+  QObject::connect(this, SIGNAL(contract_edges(unsigned)), parent, SLOT(contract_edges(unsigned)));
+
+  QObject::connect(this->pushButton_collapse, SIGNAL(clicked()), this, SLOT(send_contract_edges()));
+}
+
+void Menu_edge_contraction::slider_value_changed(int new_slider_value) {
+  int num_collapses =
+      (horizontalSlider->value() == 1) ? 1 : horizontalSlider->value() * model_.num_vertices() / 100;
+  this->txt_nb_vertices->setNum(static_cast<int>(model_.num_vertices()));
+  this->txt_nb_collapses->setNum(num_collapses);
+  this->spinBox_nb_remaining_vertices->setValue(model_.num_vertices() - num_collapses);
+}
+
+void
+Menu_edge_contraction::update_slider_value() {
+  int num_vertices = model_.num_vertices();
+  int num_collapses = (horizontalSlider->value() == 1) ? 1 : horizontalSlider->value() * num_vertices / 100;
+  int horizontal_slider_position = num_vertices > 0 ? num_collapses / static_cast<double>(num_vertices * 100) : 1;
+  horizontalSlider->setValue(horizontal_slider_position);
+}
+
+void
+Menu_edge_contraction::update_gui_numbers() {
+  update_slider_value();
+  bool ok;
+  int num_collapses = this->txt_nb_collapses->text().toInt(&ok, 10);
+  if (!ok) return;
+  this->txt_nb_vertices->setNum(static_cast<int>(model_.num_vertices()));
+  this->txt_nb_collapses->setNum(num_collapses);
+  this->spinBox_nb_remaining_vertices->setValue(model_.num_vertices() - num_collapses);
+}
+
+void
+Menu_edge_contraction::update_gui_numbers(int new_value) {
+  update_gui_numbers();
+}
+
+void
+Menu_edge_contraction::send_contract_edges() {
+  emit(contract_edges(num_collapses()));
+  update_gui_numbers();
+}
+
+unsigned
+Menu_edge_contraction::num_vertices() {
+  return model_.num_vertices();
+}
+
+unsigned
+Menu_edge_contraction::num_collapses() {
+  return (horizontalSlider->value() == 1) ? 1 : horizontalSlider->value() * num_vertices() / 100;
+}
+
+#include "Menu_edge_contraction.moc"
+
+#endif  // GUI_MENU_EDGE_CONTRACTION_CPP_
diff --git a/GudhUI/gui/Menu_edge_contraction.h b/GudhUI/gui/Menu_edge_contraction.h
new file mode 100644
index 00000000..08f0bf67
--- /dev/null
+++ b/GudhUI/gui/Menu_edge_contraction.h
@@ -0,0 +1,63 @@
+/*    This file is part of the Gudhi Library. The Gudhi library
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef GUI_MENU_EDGE_CONTRACTION_H_
+#define GUI_MENU_EDGE_CONTRACTION_H_
+
+// Workaround for moc-qt4 not parsing boost headers
+#include <CGAL/config.h>
+
+#include "gui/MainWindow.h"
+#include "gui/ui_MenuEdgeContraction.h"
+
+#include "model/Model.h"
+
+class Menu_edge_contraction : public QDialog, public Ui::MenuEdgeContraction {
+  Q_OBJECT
+
+ private:
+  MainWindow* parent_;
+  const Model& model_;
+
+  void update_slider_value();
+
+ public:
+  Menu_edge_contraction(MainWindow* parent, const Model& model);
+
+  void connectActions(MainWindow* parent);
+
+ private:
+  unsigned num_vertices();
+  unsigned num_collapses();
+
+ public slots:
+  void slider_value_changed(int new_slider_value);
+  void update_gui_numbers();
+  void update_gui_numbers(int gui_numbers);
+
+  void send_contract_edges();
+
+ signals:
+  void contract_edges(unsigned num_collapses);
+};
+
+#endif  // GUI_MENU_EDGE_CONTRACTION_H_
diff --git a/GudhUI/gui/Menu_k_nearest_neighbors.cpp b/GudhUI/gui/Menu_k_nearest_neighbors.cpp
new file mode 100644
index 00000000..e24865f2
--- /dev/null
+++ b/GudhUI/gui/Menu_k_nearest_neighbors.cpp
@@ -0,0 +1,59 @@
+/*    This file is part of the Gudhi Library. The Gudhi library
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "Menu_k_nearest_neighbors.h"
+
+Menu_k_nearest_neighbors::Menu_k_nearest_neighbors(QMainWindow* parent_)
+    : parent(parent_) {
+  setupUi(this);
+  connectActions(parent_);
+}
+
+void Menu_k_nearest_neighbors::connectActions(QMainWindow* parent) {
+  QObject::connect(this->pushButtonCompute,
+                   SIGNAL(clicked()),
+                   this,
+                   SLOT(send_compute_k_nearest_neighbors()));
+  QObject::connect(this->spinBoxK,
+                   SIGNAL(valueChanged(int)),
+                   this,
+                   SLOT(update_k(int)));
+  QObject::connect(this,
+                   SIGNAL(compute_k_nearest_neighbors(unsigned)),
+                   parent,
+                   SLOT(build_k_nearest_neighbors(unsigned)));
+}
+
+void Menu_k_nearest_neighbors::send_compute_k_nearest_neighbors() {
+  emit(compute_k_nearest_neighbors((unsigned) spinBoxK->value()));
+}
+
+void Menu_k_nearest_neighbors::accept() {
+  send_compute_k_nearest_neighbors();
+}
+
+void Menu_k_nearest_neighbors::update_k(int new_k_value) {
+  if (checkBoxAutoUpdate->isChecked())
+    emit(compute_k_nearest_neighbors((unsigned) spinBoxK->value()));
+}
+
+#include "Menu_k_nearest_neighbors.moc"
diff --git a/GudhUI/gui/Menu_k_nearest_neighbors.h b/GudhUI/gui/Menu_k_nearest_neighbors.h
new file mode 100644
index 00000000..8088b768
--- /dev/null
+++ b/GudhUI/gui/Menu_k_nearest_neighbors.h
@@ -0,0 +1,51 @@
+/*    This file is part of the Gudhi Library. The Gudhi library
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef GUI_MENU_K_NEAREST_NEIGHBORS_H_
+#define GUI_MENU_K_NEAREST_NEIGHBORS_H_
+
+#include <QMainWindow>
+#include "gui/ui_KNearestNeighborsMenu.h"
+
+class QWidget;
+
+class Menu_k_nearest_neighbors : public QDialog, public Ui::KNearestNeighborsMenu {
+  Q_OBJECT
+
+ private:
+  QMainWindow* parent;
+
+ public:
+  Menu_k_nearest_neighbors(QMainWindow* parent_);
+
+  void connectActions(QMainWindow* parent);
+
+ public slots:
+  void send_compute_k_nearest_neighbors();
+  void update_k(int k);
+  void accept();
+
+ signals:
+  void compute_k_nearest_neighbors(unsigned k);
+};
+
+#endif  // GUI_MENU_K_NEAREST_NEIGHBORS_H_
diff --git a/GudhUI/gui/Menu_persistence.cpp b/GudhUI/gui/Menu_persistence.cpp
new file mode 100644
index 00000000..016c076b
--- /dev/null
+++ b/GudhUI/gui/Menu_persistence.cpp
@@ -0,0 +1,53 @@
+/* This file is part of the Gudhi Library. The Gudhi library 
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++ 
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+
+#include "Menu_persistence.h"
+
+Menu_persistence::Menu_persistence(QMainWindow* parent_) : parent(parent_) {
+  setupUi(this);
+  connectActions(parent_);
+}
+
+void Menu_persistence::connectActions(QMainWindow* parent) {
+  QObject::connect(this,
+                   SIGNAL(compute_persistence(int, double, int, double)),
+                   parent,
+                   SLOT(compute_persistence(int, double, int, double)));
+}
+
+void Menu_persistence::send_compute_persistence() {
+  emit(compute_persistence(p_spinBox->value(), threshold_doubleSpinBox->value(),
+                           maxdimension_spinBox->value(), minpersistence_doubleSpinBox->value()));
+}
+
+void Menu_persistence::accept() {
+  send_compute_persistence();
+}
+
+// void Menu_persistence::compute_persistence(int p_fied,double threshold,int dim_max,double min_persistence) {
+//  if(checkBoxAutoUpdate->isChecked())
+//    emit(compute_k_nearest_neighbors((unsigned)spinBoxK->value()));
+// }
+
+#include "Menu_persistence.moc"
diff --git a/GudhUI/gui/Menu_persistence.h b/GudhUI/gui/Menu_persistence.h
new file mode 100644
index 00000000..8c4df158
--- /dev/null
+++ b/GudhUI/gui/Menu_persistence.h
@@ -0,0 +1,51 @@
+/* This file is part of the Gudhi Library. The Gudhi library 
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++ 
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+#ifndef GUI_MENU_PERSISTENCE_H_
+#define GUI_MENU_PERSISTENCE_H_
+
+#include <QMainWindow>
+#include "gui/ui_PersistenceMenu.h"
+
+class QWidget;
+
+class Menu_persistence : public QDialog, public Ui::PersistenceMenu {
+  Q_OBJECT
+
+ private:
+  QMainWindow* parent;
+
+ public:
+  Menu_persistence(QMainWindow* parent_);
+
+  void connectActions(QMainWindow* parent);
+
+ public slots:
+  void send_compute_persistence();
+  void accept();
+
+ signals:
+  void compute_persistence(int p_fied, double threshold, int dim_max, double min_persistence);
+};
+
+#endif  // GUI_MENU_PERSISTENCE_H_
diff --git a/GudhUI/gui/Menu_uniform_neighbors.cpp b/GudhUI/gui/Menu_uniform_neighbors.cpp
new file mode 100644
index 00000000..20e4f98f
--- /dev/null
+++ b/GudhUI/gui/Menu_uniform_neighbors.cpp
@@ -0,0 +1,60 @@
+/* This file is part of the Gudhi Library. The Gudhi library 
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++ 
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+#include "Menu_uniform_neighbors.h"
+
+Menu_uniform_neighbors::Menu_uniform_neighbors(QMainWindow* parent_) :
+    parent(parent_) {
+  setupUi(this);
+  connectActions(parent_);
+}
+
+void Menu_uniform_neighbors::connectActions(QMainWindow* parent) {
+  QObject::connect(this->pushButtonCompute,
+                   SIGNAL(clicked()),
+                   this,
+                   SLOT(send_compute_uniform_neighbors()));
+  QObject::connect(this->doubleSpinBoxAlpha,
+                   SIGNAL(valueChanged(double)),
+                   this,
+                   SLOT(update_alpha(double)));
+  QObject::connect(this,
+                   SIGNAL(compute_uniform_neighbors(double)),
+                   parent,
+                   SLOT(build_rips(double)));
+}
+
+void Menu_uniform_neighbors::send_compute_uniform_neighbors() {
+  emit(compute_uniform_neighbors(doubleSpinBoxAlpha->value()));
+}
+
+void Menu_uniform_neighbors::accept() {
+  send_compute_uniform_neighbors();
+}
+
+void Menu_uniform_neighbors::update_alpha(double alpha) {
+  if (checkBoxAutoUpdate->isChecked())
+    emit(compute_uniform_neighbors(doubleSpinBoxAlpha->value()));
+}
+
+#include "Menu_uniform_neighbors.moc"
diff --git a/GudhUI/gui/Menu_uniform_neighbors.h b/GudhUI/gui/Menu_uniform_neighbors.h
new file mode 100644
index 00000000..0b6f65fe
--- /dev/null
+++ b/GudhUI/gui/Menu_uniform_neighbors.h
@@ -0,0 +1,51 @@
+/* This file is part of the Gudhi Library. The Gudhi library 
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++ 
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+#ifndef GUI_MENU_UNIFORM_NEIGHBORS_H_
+#define GUI_MENU_UNIFORM_NEIGHBORS_H_
+
+#include <QMainWindow>
+#include "gui/ui_UniformNeighborsMenu.h"
+
+class Menu_uniform_neighbors : public QDialog, public Ui::UniformMenu {
+  Q_OBJECT
+
+ private:
+  QMainWindow* parent;
+
+ public:
+  Menu_uniform_neighbors(QMainWindow* parent_);
+
+  void connectActions(QMainWindow* parent);
+
+ public slots:
+  void send_compute_uniform_neighbors();
+  void update_alpha(double alpha);
+  void accept();
+
+ signals:
+  void compute_uniform_neighbors(double alpha);
+};
+
+
+#endif  // GUI_MENU_UNIFORM_NEIGHBORS_H_
diff --git a/GudhUI/gui/PersistenceMenu.ui b/GudhUI/gui/PersistenceMenu.ui
new file mode 100644
index 00000000..29327db2
--- /dev/null
+++ b/GudhUI/gui/PersistenceMenu.ui
@@ -0,0 +1,139 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>PersistenceMenu</class>
+ <widget class="QDialog" name="PersistenceMenu">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>354</width>
+    <height>275</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>Point cloud persistence</string>
+  </property>
+  <widget class="QWidget" name="">
+   <property name="geometry">
+    <rect>
+     <x>20</x>
+     <y>23</y>
+     <width>318</width>
+     <height>226</height>
+    </rect>
+   </property>
+   <layout class="QVBoxLayout" name="verticalLayout">
+    <item>
+     <layout class="QGridLayout" name="gridLayout">
+      <item row="0" column="0">
+       <widget class="QSpinBox" name="p_spinBox">
+        <property name="minimum">
+         <number>2</number>
+        </property>
+        <property name="value">
+         <number>2</number>
+        </property>
+       </widget>
+      </item>
+      <item row="0" column="1">
+       <widget class="QLabel" name="label">
+        <property name="text">
+         <string>Coefficient Z/pZ</string>
+        </property>
+       </widget>
+      </item>
+      <item row="1" column="0">
+       <widget class="QSpinBox" name="maxdimension_spinBox">
+        <property name="maximum">
+         <number>9999</number>
+        </property>
+        <property name="value">
+         <number>10</number>
+        </property>
+       </widget>
+      </item>
+      <item row="1" column="1">
+       <widget class="QLabel" name="label_4">
+        <property name="text">
+         <string>Max dimension</string>
+        </property>
+       </widget>
+      </item>
+      <item row="2" column="0">
+       <widget class="QDoubleSpinBox" name="threshold_doubleSpinBox">
+        <property name="maximum">
+         <double>9999.000000000000000</double>
+        </property>
+        <property name="value">
+         <double>1.000000000000000</double>
+        </property>
+       </widget>
+      </item>
+      <item row="2" column="1">
+       <widget class="QLabel" name="label_2">
+        <property name="text">
+         <string>Max Rips offset</string>
+        </property>
+       </widget>
+      </item>
+      <item row="3" column="0">
+       <widget class="QDoubleSpinBox" name="minpersistence_doubleSpinBox"/>
+      </item>
+      <item row="3" column="1">
+       <widget class="QLabel" name="label_3">
+        <property name="text">
+         <string>Minimum Persistence</string>
+        </property>
+       </widget>
+      </item>
+     </layout>
+    </item>
+    <item>
+     <widget class="QDialogButtonBox" name="buttonBox">
+      <property name="orientation">
+       <enum>Qt::Horizontal</enum>
+      </property>
+      <property name="standardButtons">
+       <set>QDialogButtonBox::Cancel|QDialogButtonBox::Ok</set>
+      </property>
+     </widget>
+    </item>
+   </layout>
+  </widget>
+ </widget>
+ <resources/>
+ <connections>
+  <connection>
+   <sender>buttonBox</sender>
+   <signal>accepted()</signal>
+   <receiver>PersistenceMenu</receiver>
+   <slot>accept()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>248</x>
+     <y>254</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>157</x>
+     <y>274</y>
+    </hint>
+   </hints>
+  </connection>
+  <connection>
+   <sender>buttonBox</sender>
+   <signal>rejected()</signal>
+   <receiver>PersistenceMenu</receiver>
+   <slot>reject()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>316</x>
+     <y>260</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>286</x>
+     <y>274</y>
+    </hint>
+   </hints>
+  </connection>
+ </connections>
+</ui>
diff --git a/GudhUI/gui/UniformNeighborsMenu.ui b/GudhUI/gui/UniformNeighborsMenu.ui
new file mode 100644
index 00000000..f8ef7a24
--- /dev/null
+++ b/GudhUI/gui/UniformNeighborsMenu.ui
@@ -0,0 +1,153 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>UniformMenu</class>
+ <widget class="QDialog" name="UniformMenu">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>292</width>
+    <height>209</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>Uniform neighbors (Rips)</string>
+  </property>
+  <widget class="QDialogButtonBox" name="buttonBox">
+   <property name="geometry">
+    <rect>
+     <x>50</x>
+     <y>160</y>
+     <width>171</width>
+     <height>32</height>
+    </rect>
+   </property>
+   <property name="orientation">
+    <enum>Qt::Horizontal</enum>
+   </property>
+   <property name="standardButtons">
+    <set>QDialogButtonBox::Cancel|QDialogButtonBox::Ok</set>
+   </property>
+  </widget>
+  <widget class="QWidget" name="formLayoutWidget">
+   <property name="geometry">
+    <rect>
+     <x>30</x>
+     <y>10</y>
+     <width>262</width>
+     <height>84</height>
+    </rect>
+   </property>
+   <layout class="QFormLayout" name="formLayout_2">
+    <property name="fieldGrowthPolicy">
+     <enum>QFormLayout::AllNonFixedFieldsGrow</enum>
+    </property>
+    <item row="0" column="0">
+     <widget class="QLabel" name="label">
+      <property name="text">
+       <string>alpha</string>
+      </property>
+     </widget>
+    </item>
+    <item row="1" column="0">
+     <widget class="QLabel" name="label_2">
+      <property name="text">
+       <string>Metric</string>
+      </property>
+     </widget>
+    </item>
+    <item row="1" column="1">
+     <widget class="QComboBox" name="comboBoxMetric">
+      <item>
+       <property name="text">
+        <string>Ambient</string>
+       </property>
+      </item>
+      <item>
+       <property name="text">
+        <string>Reduced Space</string>
+       </property>
+      </item>
+     </widget>
+    </item>
+    <item row="0" column="1">
+     <widget class="QDoubleSpinBox" name="doubleSpinBoxAlpha">
+      <property name="decimals">
+       <number>3</number>
+      </property>
+      <property name="maximum">
+       <double>100000000.000000000000000</double>
+      </property>
+      <property name="singleStep">
+       <double>0.100000000000000</double>
+      </property>
+     </widget>
+    </item>
+   </layout>
+  </widget>
+  <widget class="QWidget" name="gridLayoutWidget">
+   <property name="geometry">
+    <rect>
+     <x>30</x>
+     <y>110</y>
+     <width>250</width>
+     <height>40</height>
+    </rect>
+   </property>
+   <layout class="QGridLayout" name="gridLayout">
+    <item row="0" column="1">
+     <widget class="QPushButton" name="pushButtonCompute">
+      <property name="text">
+       <string>Compute</string>
+      </property>
+     </widget>
+    </item>
+    <item row="0" column="0">
+     <widget class="QCheckBox" name="checkBoxAutoUpdate">
+      <property name="text">
+       <string>auto update</string>
+      </property>
+      <property name="checked">
+       <bool>true</bool>
+      </property>
+     </widget>
+    </item>
+   </layout>
+  </widget>
+ </widget>
+ <resources/>
+ <connections>
+  <connection>
+   <sender>buttonBox</sender>
+   <signal>accepted()</signal>
+   <receiver>UniformMenu</receiver>
+   <slot>accept()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>248</x>
+     <y>254</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>157</x>
+     <y>274</y>
+    </hint>
+   </hints>
+  </connection>
+  <connection>
+   <sender>buttonBox</sender>
+   <signal>rejected()</signal>
+   <receiver>UniformMenu</receiver>
+   <slot>reject()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>316</x>
+     <y>260</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>286</x>
+     <y>274</y>
+    </hint>
+   </hints>
+  </connection>
+ </connections>
+</ui>
diff --git a/GudhUI/gui/gudhui.cpp b/GudhUI/gui/gudhui.cpp
new file mode 100644
index 00000000..276c4a5f
--- /dev/null
+++ b/GudhUI/gui/gudhui.cpp
@@ -0,0 +1,38 @@
+/* This file is part of the Gudhi Library. The Gudhi library 
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++ 
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+#include "MainWindow.h"
+#include <QApplication>
+#include <CGAL/Qt/resources.h>
+
+int main(int argc, char** argv) {
+  QApplication application(argc, argv);
+  application.setOrganizationDomain("inria.fr");
+  application.setOrganizationName("INRIA");
+  application.setApplicationName("GudhUI");
+
+  MainWindow mw;
+  application.setQuitOnLastWindowClosed(false);
+  mw.show();
+  return application.exec();
+}
diff --git a/GudhUI/gui/main_window.ui b/GudhUI/gui/main_window.ui
new file mode 100644
index 00000000..312480b6
--- /dev/null
+++ b/GudhUI/gui/main_window.ui
@@ -0,0 +1,255 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>MainWindow</class>
+ <widget class="QMainWindow" name="MainWindow">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>861</width>
+    <height>880</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>GudhUI</string>
+  </property>
+  <property name="tabShape">
+   <enum>QTabWidget::Rounded</enum>
+  </property>
+  <widget class="QWidget" name="centralwidget">
+   <layout class="QVBoxLayout" name="verticalLayout_2">
+    <item>
+     <layout class="QHBoxLayout" name="horizontalLayout">
+      <item>
+       <widget class="Viewer" name="viewer" native="true">
+        <property name="autoFillBackground">
+         <bool>false</bool>
+        </property>
+       </widget>
+      </item>
+     </layout>
+    </item>
+   </layout>
+  </widget>
+  <widget class="QMenuBar" name="menubar">
+   <property name="geometry">
+    <rect>
+     <x>0</x>
+     <y>0</y>
+     <width>861</width>
+     <height>34</height>
+    </rect>
+   </property>
+   <widget class="QMenu" name="menuFile">
+    <property name="title">
+     <string>File</string>
+    </property>
+    <addaction name="actionLoad_points"/>
+    <addaction name="actionLoad_complex"/>
+    <addaction name="actionSave_points"/>
+    <addaction name="actionSave_complex"/>
+   </widget>
+   <widget class="QMenu" name="menuPoints">
+    <property name="title">
+     <string>Points</string>
+    </property>
+    <addaction name="actionNoise"/>
+   </widget>
+   <widget class="QMenu" name="menuGraph">
+    <property name="title">
+     <string>Graph</string>
+    </property>
+    <addaction name="actionK_nearest_neighbors_graph"/>
+    <addaction name="actionUniform_proximity_graph"/>
+    <addaction name="actionShow_graph_stats"/>
+   </widget>
+   <widget class="QMenu" name="menuComplex">
+    <property name="title">
+     <string>Complex</string>
+    </property>
+    <addaction name="actionContract_edges"/>
+    <addaction name="actionCollapse_vertices"/>
+    <addaction name="actionCollapse_edges"/>
+    <addaction name="actionShow_complex_stats"/>
+    <addaction name="actionShow_complex_dimension"/>
+   </widget>
+   <widget class="QMenu" name="menuView">
+    <property name="title">
+     <string>View</string>
+    </property>
+    <addaction name="actionPoints"/>
+    <addaction name="actionEdges"/>
+    <addaction name="actionTriangles"/>
+    <addaction name="actionChange_projection"/>
+   </widget>
+   <widget class="QMenu" name="menuTopology">
+    <property name="title">
+     <string>Topology</string>
+    </property>
+    <addaction name="actionEuler_characteristic"/>
+    <addaction name="actionShow_homology_group"/>
+    <addaction name="actionPersistence"/>
+    <addaction name="actionEstimate_topological_changes"/>
+    <addaction name="actionIs_manifold"/>
+   </widget>
+   <addaction name="menuFile"/>
+   <addaction name="menuPoints"/>
+   <addaction name="menuGraph"/>
+   <addaction name="menuComplex"/>
+   <addaction name="menuTopology"/>
+   <addaction name="menuView"/>
+  </widget>
+  <widget class="QStatusBar" name="statusbar"/>
+  <action name="actionLoad_points">
+   <property name="text">
+    <string>Load points</string>
+   </property>
+  </action>
+  <action name="actionLoad_complex">
+   <property name="text">
+    <string>Load complex</string>
+   </property>
+  </action>
+  <action name="actionSave_points">
+   <property name="text">
+    <string>Save points</string>
+   </property>
+  </action>
+  <action name="actionSave_complex">
+   <property name="text">
+    <string>Save complex</string>
+   </property>
+  </action>
+  <action name="actionNoise">
+   <property name="text">
+    <string>Noise</string>
+   </property>
+  </action>
+  <action name="actionLloyd">
+   <property name="text">
+    <string>Lloyd</string>
+   </property>
+  </action>
+  <action name="actionUniform_proximity_graph">
+   <property name="text">
+    <string>Uniform proximity graph</string>
+   </property>
+  </action>
+  <action name="actionK_nearest_neighbors_graph">
+   <property name="text">
+    <string>k-nearest neighbors graph</string>
+   </property>
+  </action>
+  <action name="actionShow_graph_stats">
+   <property name="text">
+    <string>Show graph stats</string>
+   </property>
+  </action>
+  <action name="actionBuild_complex_from_graph">
+   <property name="text">
+    <string>Graph expansion</string>
+   </property>
+  </action>
+  <action name="actionBuild_Delaunay_from_points">
+   <property name="text">
+    <string>Delaunay from points</string>
+   </property>
+  </action>
+  <action name="actionContract_edges">
+   <property name="text">
+    <string>Contract edges</string>
+   </property>
+  </action>
+  <action name="actionCollapse_vertices">
+   <property name="text">
+    <string>Collapse vertices</string>
+   </property>
+  </action>
+  <action name="actionCollapse_edges">
+   <property name="text">
+    <string>Collapse edges</string>
+   </property>
+  </action>
+  <action name="actionPoints">
+   <property name="text">
+    <string>Points</string>
+   </property>
+  </action>
+  <action name="actionEdges">
+   <property name="text">
+    <string>Edges</string>
+   </property>
+  </action>
+  <action name="actionTriangles">
+   <property name="text">
+    <string>Triangles</string>
+   </property>
+  </action>
+  <action name="actionChange_projection">
+   <property name="text">
+    <string>Change projection</string>
+   </property>
+  </action>
+  <action name="actionShow_complex_stats">
+   <property name="text">
+    <string>Show complex stats</string>
+   </property>
+  </action>
+  <action name="actionShow_complex_dimension">
+   <property name="text">
+    <string>Show complex dimension</string>
+   </property>
+  </action>
+  <action name="actionShow_homology_group">
+   <property name="text">
+    <string>Homology groups</string>
+   </property>
+  </action>
+  <action name="actionPersistence">
+   <property name="text">
+    <string>Point cloud persistence</string>
+   </property>
+  </action>
+  <action name="actionEuler_characteristic">
+   <property name="enabled">
+    <bool>true</bool>
+   </property>
+   <property name="text">
+    <string>Euler characteristic</string>
+   </property>
+   <property name="visible">
+    <bool>true</bool>
+   </property>
+  </action>
+  <action name="actionHomology_groups">
+   <property name="text">
+    <string>Homology groups</string>
+   </property>
+  </action>
+  <action name="actionEstimate_topological_changes">
+   <property name="enabled">
+    <bool>false</bool>
+   </property>
+   <property name="text">
+    <string>Rips critical points approximation</string>
+   </property>
+   <property name="visible">
+    <bool>false</bool>
+   </property>
+  </action>
+  <action name="actionIs_manifold">
+   <property name="text">
+    <string>Is manifold</string>
+   </property>
+  </action>
+ </widget>
+ <customwidgets>
+  <customwidget>
+   <class>Viewer</class>
+   <extends>QWidget</extends>
+   <header>view/Viewer.h</header>
+  </customwidget>
+ </customwidgets>
+ <resources/>
+ <connections/>
+</ui>
diff --git a/GudhUI/model/Complex_typedefs.h b/GudhUI/model/Complex_typedefs.h
new file mode 100644
index 00000000..a4df2c94
--- /dev/null
+++ b/GudhUI/model/Complex_typedefs.h
@@ -0,0 +1,49 @@
+/* This file is part of the Gudhi Library. The Gudhi library 
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++ 
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+#ifndef MODEL_COMPLEX_TYPEDEFS_H_
+#define MODEL_COMPLEX_TYPEDEFS_H_
+
+#include <gudhi/Skeleton_blocker/Skeleton_blocker_simple_geometric_traits.h>
+#include <gudhi/Skeleton_blocker_geometric_complex.h>
+
+#include <CGAL/Kernel_d/Point_d.h>
+#include <CGAL/Cartesian.h>
+#include <CGAL/Cartesian_d.h>
+
+struct Geometry_trait : public CGAL::Cartesian_d<double> {
+  typedef CGAL::Cartesian<double>::Point_3 Point_3;
+  typedef CGAL::Cartesian<double>::Vector_3 Vector_3;
+  typedef CGAL::Point_d<Cartesian_d<double>> Point;
+  typedef CGAL::Vector_d<Cartesian_d<double>> Vector;
+};
+
+typedef Geometry_trait::Point Point;
+
+using namespace Gudhi;
+using namespace Gudhi::skeleton_blocker;
+
+typedef Skeleton_blocker_simple_geometric_traits<Geometry_trait> Complex_geometric_traits;
+typedef Skeleton_blocker_geometric_complex< Complex_geometric_traits > Complex;
+
+#endif  // MODEL_COMPLEX_TYPEDEFS_H_
diff --git a/GudhUI/model/Model.h b/GudhUI/model/Model.h
new file mode 100644
index 00000000..1c39c0d7
--- /dev/null
+++ b/GudhUI/model/Model.h
@@ -0,0 +1,355 @@
+/* This file is part of the Gudhi Library. The Gudhi library 
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++ 
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+#ifndef MODEL_MODEL_H_
+#define MODEL_MODEL_H_
+
+#include <gudhi/Clock.h>
+#include <gudhi/Skeleton_blocker/Skeleton_blocker_simple_geometric_traits.h>
+#include <gudhi/Skeleton_blocker_geometric_complex.h>
+#include <gudhi/Off_reader.h>
+
+#include <CGAL/Euclidean_distance.h>
+
+#include <fstream>
+#include <limits>
+#include <string>
+#include <vector>
+
+#include "utils/UI_utils.h"
+#include "utils/Lloyd_builder.h"
+#include "utils/Rips_builder.h"
+#include "utils/K_nearest_builder.h"
+#include "utils/Vertex_collapsor.h"
+#include "utils/Edge_collapsor.h"
+#include "utils/Edge_contractor.h"
+#include "utils/Persistence_compute.h"
+#include "utils/Critical_points.h"
+#include "utils/Is_manifold.h"
+
+#include "Complex_typedefs.h"
+
+template<typename Complex>
+class CGAL_geometric_flag_complex_wrapper {
+  Complex& complex_;
+  typedef typename Complex::Vertex_handle Vertex_handle;
+  typedef typename Complex::Point Point;
+
+  const bool load_only_points_;
+
+ public:
+  CGAL_geometric_flag_complex_wrapper(Complex& complex, bool load_only_points = false) :
+      complex_(complex),
+      load_only_points_(load_only_points) { }
+
+  void init(int dim, int num_vertices, int num_max_faces, int num_edges) const { }
+
+  void point(const std::vector<double>& coords) {
+    Point p(coords.size(), coords.begin(), coords.end());
+    complex_.add_vertex(p);
+  }
+
+  void maximal_face(std::vector<int> vertices) {
+    if (!load_only_points_) {
+      // std::cout << "size:" << vertices.size() << std::endl;
+      for (int i = 0; i < vertices.size(); ++i)
+        for (int j = i + 1; j < vertices.size(); ++j)
+          complex_.add_edge(Vertex_handle(vertices[i]), Vertex_handle(vertices[j]));
+    }
+  }
+
+  void done() const { }
+};
+
+class Model {
+ public:
+  Complex complex_;
+  typedef Complex::Vertex_handle Vertex_handle;
+
+  Model() : complex_() { }
+
+ public:
+  void off_file_open(const std::string& name_file) {
+    UIDBGMSG("load off file", name_file);
+    complex_.clear();
+    CGAL_geometric_flag_complex_wrapper<Complex> read_wraper(complex_, false);
+    Gudhi::read_off(name_file, read_wraper);
+  }
+
+  void off_points_open(const std::string& name_file) {
+    UIDBGMSG("load off points", name_file);
+    complex_.clear();
+    CGAL_geometric_flag_complex_wrapper<Complex> read_wraper(complex_, true);
+    Gudhi::read_off(name_file, read_wraper);
+  }
+
+  void off_file_save(const std::string& name_file) {
+    UIDBG("save off file");
+    UIDBG("save off off_points_save");
+    std::ofstream file(name_file);
+    if (file.is_open()) {
+      file << "OFF\n";
+      file << complex_.num_vertices() << " " << complex_.num_edges() << " 0\n";
+      for (auto v : complex_.vertex_range()) {
+        const auto& pt(complex_.point(v));
+        for (auto it = pt.cartesian_begin(); it != pt.cartesian_end(); ++it)
+          file << *it << " ";
+        file << std::endl;
+      }
+      for (auto e : complex_.edge_range())
+        file << "2 " << complex_.first_vertex(e) << " " << complex_.second_vertex(e) << "\n";
+      file.close();
+    } else {
+      std::cerr << "Could not open file " << name_file << std::endl;
+    }
+  }
+
+  void off_points_save(const std::string& name_file) {
+    UIDBG("save off off_points_save");
+    std::ofstream file(name_file);
+    if (file.is_open()) {
+      file << "OFF\n";
+      file << complex_.num_vertices() << " 0 0\n";
+      for (auto v : complex_.vertex_range()) {
+        const auto& pt(complex_.point(v));
+        for (auto it = pt.cartesian_begin(); it != pt.cartesian_end(); ++it)
+          file << *it << " ";
+        file << std::endl;
+      }
+      file.close();
+    } else {
+      std::cerr << "Could not open file " << name_file << std::endl;
+    }
+  }
+
+  // point sets operations
+  void uniform_noise(double amplitude) {
+    UIDBG("unif noise");
+    for (auto v : complex_.vertex_range())
+      complex_.point(v) = add_uniform_noise(complex_.point(v), amplitude);
+  }
+
+ private:
+  Point add_uniform_noise(const Point& point, double amplitude) {
+    std::vector<double> new_point(point.dimension());
+    for (int i = 0; i < point.dimension(); ++i) {
+      new_point[i] = point[i] + (rand() % 2 - .5) * amplitude;
+    }
+    return Point(point.dimension(), new_point.begin(), new_point.end());
+  }
+
+ public:
+  void lloyd(int num_iterations, int num_closest_neighbors) {
+    UIDBG("lloyd");
+    Lloyd_builder<Complex> lloyd_builder(complex_, 1);
+  }
+
+  double squared_eucl_distance(const Point& p1, const Point& p2) const {
+    return Geometry_trait::Squared_distance_d()(p1, p2);
+  }
+
+  // complex operations from points
+
+  void build_rips(double alpha) {
+    UIDBG("build_rips");
+    Rips_builder<Complex> rips_builder(complex_, alpha);
+  }
+
+  void build_k_nearest_neighbors(unsigned k) {
+    UIDBG("build_k_nearest");
+    complex_.keep_only_vertices();
+    K_nearest_builder<Complex> k_nearest_builder(complex_, k);
+  }
+
+  void build_delaunay() {
+    UIDBG("build_delaunay");
+    complex_.keep_only_vertices();
+  }
+
+  void contract_edges(unsigned num_contractions) {
+    Clock c;
+    Edge_contractor<Complex> contractor(complex_, num_contractions);
+    std::cout << "Time to simplify: " << c.num_seconds() << "s" << std::endl;
+  }
+
+  void collapse_vertices(unsigned num_collapses) {
+    auto old_num_vertices = complex_.num_vertices();
+    Vertex_collapsor<Complex> collapsor(complex_, complex_.num_vertices());
+    UIDBGMSG("num vertices collapsed:", old_num_vertices - complex_.num_vertices());
+  }
+
+  void collapse_edges(unsigned num_collapses) {
+    Edge_collapsor<Complex> collapsor(complex_, num_collapses);
+  }
+
+  void show_graph_stats() {
+    std::cout << "++++++ Graph stats +++++++" << std::endl;
+    std::cout << "Num vertices : " << complex_.num_vertices() << std::endl;
+    std::cout << "Num edges : " << complex_.num_edges() << std::endl;
+    std::cout << "Num connected components : " << complex_.num_connected_components() << std::endl;
+    std::cout << "Min/avg/max degree : " << min_degree() << "/" << avg_degree() << "/" << max_degree() << std::endl;
+    std::cout << "Num connected components : " << complex_.num_connected_components() << std::endl;
+    std::cout << "Num connected components : " << complex_.num_connected_components() << std::endl;
+    std::cout << "+++++++++++++++++++++++++" << std::endl;
+  }
+
+ private:
+  int min_degree() const {
+    int res = (std::numeric_limits<int>::max)();
+    for (auto v : complex_.vertex_range())
+      res = (std::min)(res, complex_.degree(v));
+    return res;
+  }
+
+  int max_degree() const {
+    int res = 0;
+    for (auto v : complex_.vertex_range())
+      res = (std::max)(res, complex_.degree(v));
+    return res;
+  }
+
+  int avg_degree() const {
+    int res = 0;
+    for (auto v : complex_.vertex_range())
+      res += complex_.degree(v);
+    return res / complex_.num_vertices();
+  }
+
+ public:
+  void show_complex_stats() {
+    std::cout << "++++++ Mesh stats +++++++" << std::endl;
+    std::cout << "Num vertices : " << complex_.num_vertices() << std::endl;
+    std::cout << "Num edges : " << complex_.num_edges() << std::endl;
+    std::cout << "Num connected components : " << complex_.num_connected_components() << std::endl;
+    std::cout << "+++++++++++++++++++++++++" << std::endl;
+  }
+
+  void show_complex_dimension() {
+    unsigned num_simplices = 0;
+    int euler = 0;
+    int dimension = 0;
+    Clock clock;
+    for (const auto &s : complex_.complex_simplex_range()) {
+      num_simplices++;
+      dimension = (std::max)(s.dimension(), dimension);
+      if (s.dimension() % 2 == 0)
+        euler += 1;
+      else
+        euler -= 1;
+    }
+    clock.end();
+    std::cout << "++++++ Mesh dimension +++++++" << std::endl;
+    std::cout << "Dimension : " << dimension << std::endl;
+    std::cout << "Euler characteristic : " << euler << std::endl;
+    std::cout << "Num simplices : " << num_simplices << std::endl;
+    std::cout << "Total time: " << clock << std::endl;
+    std::cout << "Time per simplex: " << clock.num_seconds() / num_simplices << " s" << std::endl;
+    std::cout << "+++++++++++++++++++++++++" << std::endl;
+  }
+
+  void show_homology_group() {
+#ifdef _WIN32
+    std::cout << "Works only on linux x64 for the moment\n";
+#else
+    Clock clock;
+    run_chomp();
+    clock.end();
+#endif
+  }
+
+  void show_euler_characteristic() {
+    unsigned num_simplices = 0;
+    int euler = 0;
+    int dimension = 0;
+    for (const auto &s : complex_.complex_simplex_range()) {
+      num_simplices++;
+      dimension = (std::max)(s.dimension(), dimension);
+      if (s.dimension() % 2 == 0)
+        euler += 1;
+      else
+        euler -= 1;
+    }
+    std::cout << "Saw " << num_simplices << " simplices with maximum dimension " << dimension << std::endl;
+    std::cout << "The euler characteristic is : " << euler << std::endl;
+  }
+
+  void show_persistence(int p, double threshold, int max_dim, double min_pers) {
+    Persistence_compute<Complex> persistence(complex_, std::cout, Persistence_params(p, threshold, max_dim, min_pers));
+  }
+
+  void show_critical_points(double max_distance) {
+    Critical_points<Complex> critical_points(complex_, std::cout, max_distance);
+  }
+
+  void show_is_manifold() {
+    unsigned dim;
+    bool is_manifold;
+    Is_manifold<Complex> test_manifold(complex_, dim, is_manifold);
+
+    if (is_manifold) {
+      std::cout << "The complex is a " << dim << "-manifold\n";
+    } else {
+      if (dim < 4) {
+        std::cout << "The complex has dimension greater than " << dim << " and is not a manifold\n";
+      } else {
+        std::cout << "The complex has dimension>=4 and may or may not be a manifold\n";
+      }
+    }
+  }
+
+ private:
+  void run_chomp() {
+    save_complex_in_file_for_chomp();
+    std::cout << "Call CHOMP library\n";
+    int returnValue = system("utils/homsimpl chomp.sim");
+    std::cout << "CHOMP returns" << returnValue << std::endl;
+  }
+
+  void save_complex_in_file_for_chomp() {
+    std::ofstream file;
+    file.open("chomp.sim");
+    for (const auto &s : complex_.complex_simplex_range()) {
+      bool first = true;
+      file << "(";
+      for (auto x : s) {
+        if (first)
+          first = false;
+        else
+          file << ",";
+        file << x;
+      }
+      file << ")\n";
+    }
+  }
+
+ public:
+  unsigned num_vertices() const {
+    return complex_.num_vertices();
+  }
+
+  unsigned num_edges() const {
+    return complex_.num_edges();
+  }
+};
+
+#endif  // MODEL_MODEL_H_
diff --git a/GudhUI/todo.txt b/GudhUI/todo.txt
new file mode 100644
index 00000000..19d99a77
--- /dev/null
+++ b/GudhUI/todo.txt
@@ -0,0 +1,22 @@
+-- general 
+
+o bug avec kreanrest neighbors lorsqu on baisse k après contraction après collapse vertices
+
+o clarify visitor sk_bl
+
+
+
+-- ui
+
+x points dimension arbitraire
+x contractions
+
+
+x faire le lien MainWindow - Model
+
+
+
+
+-- bug
+x bug ordre contraction -> just that first vertex placement dont work great
+x pb construction rips
diff --git a/GudhUI/utils/Bar_code_persistence.h b/GudhUI/utils/Bar_code_persistence.h
new file mode 100644
index 00000000..b527d684
--- /dev/null
+++ b/GudhUI/utils/Bar_code_persistence.h
@@ -0,0 +1,90 @@
+#include <math.h>  // isfinite
+
+#include <QtGui/QApplication>
+
+#include <QGraphicsView>
+#include <QGraphicsScene>
+#include <QPointF>
+#include <QVector>
+#include <QGraphicsTextItem>
+
+#include <iostream>
+#include <vector>
+#include <limits>  // NaN, infinity
+#include <utility>  // for pair
+#include <string>
+
+#ifndef UTILS_BAR_CODE_PERSISTENCE_H_
+#define UTILS_BAR_CODE_PERSISTENCE_H_
+
+class Bar_code_persistence {
+ private:
+  typedef std::vector<std::pair<double, double>> Persistence;
+  Persistence persistence_vector;
+  double min_birth;
+  double max_death;
+
+ public:
+  Bar_code_persistence()
+      : min_birth(std::numeric_limits<double>::quiet_NaN()),
+      max_death(std::numeric_limits<double>::quiet_NaN()) { }
+
+  void insert(double birth, double death) {
+    persistence_vector.push_back(std::make_pair(birth, death));
+    if (std::isfinite(birth)) {
+      if ((birth < min_birth) || (std::isnan(min_birth)))
+        min_birth = birth;
+      if ((birth > max_death) || (std::isnan(max_death)))
+        max_death = birth;
+    }
+    if (std::isfinite(death))
+      if ((death > max_death) || (std::isnan(max_death)))
+        max_death = death;
+  }
+
+  void show(const std::string& window_title) {
+    // Create a view, put a scene in it
+    QGraphicsView * view = new QGraphicsView();
+    QGraphicsScene * scene = new QGraphicsScene();
+    view->setScene(scene);
+    double ratio = 600.0 / (max_death - min_birth);
+    // std::cout << "min_birth=" << min_birth << " - max_death=" << max_death << " - ratio=" << ratio << std::endl;
+
+    double height = 0.0, birth = 0.0, death = 0.0;
+    int pers_num = 1;
+    for (auto& persistence : persistence_vector) {
+      height = 5.0 * pers_num;
+      // std::cout << "[" << pers_num << "] birth=" << persistence.first << " - death=" << persistence.second << std::endl;
+      if (std::isfinite(persistence.first))
+        birth = ((persistence.first - min_birth) * ratio) + 50.0;
+      else
+        birth = 0.0;
+
+      if (std::isfinite(persistence.second))
+        death = ((persistence.second - min_birth) * ratio) + 50.0;
+      else
+        death = 700.0;
+
+      scene->addLine(birth, height, death, height, QPen(Qt::blue, 2));
+      pers_num++;
+    }
+    height += 10.0;
+    // scale line
+    scene->addLine(0, height, 700.0, height, QPen(Qt::black, 1));
+    int modulo = 0;
+    for (double scale = 50.0; scale < 700.0; scale += 50.0) {
+      modulo++;
+      // scale small dash
+      scene->addLine(scale, height - 3.0, scale, height + 3.0, QPen(Qt::black, 1));
+      // scale text
+      QString scale_value = QString::number(((scale - 50.0) / ratio) + min_birth);
+      QGraphicsTextItem* dimText = scene->addText(scale_value, QFont("Helvetica", 8));
+      dimText->setPos(scale - (3.0 * scale_value.size()), height + 9.0 * (modulo % 2));
+    }
+    view->setWindowTitle(window_title.c_str());
+    // Show the view
+    view->show();
+  }
+};
+
+#endif  // UTILS_BAR_CODE_PERSISTENCE_H_
diff --git a/GudhUI/utils/Critical_points.h b/GudhUI/utils/Critical_points.h
new file mode 100644
index 00000000..3021a5fe
--- /dev/null
+++ b/GudhUI/utils/Critical_points.h
@@ -0,0 +1,132 @@
+/* This file is part of the Gudhi Library. The Gudhi library 
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++ 
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+#ifndef UTILS_CRITICAL_POINTS_H_
+#define UTILS_CRITICAL_POINTS_H_
+
+#include <deque>
+#include <utility>  // for pair<>
+#include <algorithm>  // for sort
+
+#include "utils/Edge_contractor.h"
+
+/**
+ * Iteratively tries to anticollapse smallest edge non added so far.
+ * If its link is contractible then no topological change and else possible topological change.
+ *
+ * todo do a sparsification with some parameter eps while growing
+ */
+template<typename SkBlComplex> class Critical_points {
+ private:
+  SkBlComplex filled_complex_;
+  const SkBlComplex& input_complex_;
+  double max_length_;
+  std::ostream& stream_;
+
+ public:
+  typedef typename SkBlComplex::Vertex_handle Vertex_handle;
+  typedef typename SkBlComplex::Edge_handle Edge_handle;
+  typedef typename std::pair<Vertex_handle, Vertex_handle> Edge;
+
+  /**
+   * @brief check all pair of points with length smaller than max_length
+   */
+  Critical_points(const SkBlComplex& input_complex, std::ostream& stream, double max_length) :
+      input_complex_(input_complex), max_length_(max_length), stream_(stream) {
+    std::deque<Edge> edges;
+    auto vertices = input_complex.vertex_range();
+    for (auto p = vertices.begin(); p != vertices.end(); ++p) {
+      filled_complex_.add_vertex(input_complex.point(*p));
+      for (auto q = p; ++q != vertices.end(); /**/)
+        if (squared_eucl_distance(input_complex.point(*p), input_complex.point(*q)) < max_length_ * max_length_)
+          edges.emplace_back(*p, *q);
+    }
+
+    std::sort(edges.begin(), edges.end(),
+              [&](Edge e1, Edge e2) {
+                return squared_edge_length(e1) < squared_edge_length(e2);
+              });
+
+    anti_collapse_edges(edges);
+  }
+
+ private:
+  double squared_eucl_distance(const Point& p1, const Point& p2) const {
+    return Geometry_trait::Squared_distance_d()(p1, p2);
+  }
+
+  void anti_collapse_edges(const std::deque<Edge>& edges) {
+    unsigned pos = 0;
+    for (Edge e : edges) {
+      std::cout << "edge " << pos++ << "/" << edges.size() << "\n";
+      auto eh = filled_complex_.add_edge(e.first, e.second);
+      int is_contractible(is_link_reducible(eh));
+
+      switch (is_contractible) {
+        case 0:
+          stream_ << "alpha=" << std::sqrt(squared_edge_length(e)) << " topological change" << std::endl;
+          break;
+        case 2:
+          stream_ << "alpha=" << std::sqrt(squared_edge_length(e)) << " maybe a topological change" << std::endl;
+          break;
+        default:
+          break;
+      }
+    }
+  }
+
+  // 0 -> not
+  // 1 -> yes
+  // 2 -> maybe
+
+  int is_link_reducible(Edge_handle e) {
+    auto link = filled_complex_.link(e);
+
+    if (link.empty())
+      return 0;
+
+    Edge_contractor<Complex> contractor(link, link.num_vertices() - 1);
+
+    if (link.num_connected_components() > 1)
+      // one than more CC -> not contractible
+      return 0;
+
+    if (link.num_vertices() == 1)
+      // reduced to one point -> contractible
+      return 1;
+    else
+      // we dont know
+      return 2;
+  }
+
+  double squared_edge_length(Edge_handle e) const {
+    return squared_eucl_distance(input_complex_.point(input_complex_.first_vertex(e)),
+                                 input_complex_.point(input_complex_.second_vertex(e)));
+  }
+
+  double squared_edge_length(Edge e) const {
+    return squared_eucl_distance(input_complex_.point(e.first), input_complex_.point(e.second));
+  }
+};
+
+#endif  // UTILS_CRITICAL_POINTS_H_
diff --git a/GudhUI/utils/Edge_collapsor.h b/GudhUI/utils/Edge_collapsor.h
new file mode 100644
index 00000000..151e9b01
--- /dev/null
+++ b/GudhUI/utils/Edge_collapsor.h
@@ -0,0 +1,97 @@
+/* This file is part of the Gudhi Library. The Gudhi library 
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++ 
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+#ifndef UTILS_EDGE_COLLAPSOR_H_
+#define UTILS_EDGE_COLLAPSOR_H_
+
+#include <list>
+#include "utils/Edge_contractor.h"
+#include "utils/UI_utils.h"
+
+/**
+ * Iteratively puts every vertex at the center of its neighbors
+ */
+template<typename SkBlComplex> class Edge_collapsor {
+ private:
+  SkBlComplex& complex_;
+  unsigned num_collapses_;
+
+ public:
+  typedef typename SkBlComplex::Vertex_handle Vertex_handle;
+  typedef typename SkBlComplex::Edge_handle Edge_handle;
+
+  /**
+   * @brief Collapse num_collapses edges. If num_collapses<0 then it collapses all possible edges.
+   * Largest edges are collapsed first.
+   *
+   */
+  Edge_collapsor(SkBlComplex& complex, unsigned num_collapses) :
+      complex_(complex), num_collapses_(num_collapses) {
+    std::list<Edge_handle> edges;
+    edges.insert(edges.begin(), complex_.edge_range().begin(), complex_.edge_range().end());
+
+    edges.sort(
+               [&](Edge_handle e1, Edge_handle e2) {
+                 return squared_edge_length(e1) < squared_edge_length(e2);
+               });
+
+    collapse_edges(edges);
+  }
+
+ private:
+  void collapse_edges(std::list<Edge_handle>& edges) {
+    while (!edges.empty() && num_collapses_--) {
+      Edge_handle current_edge = edges.front();
+      edges.pop_front();
+      if (is_link_reducible(current_edge))
+        complex_.remove_edge(current_edge);
+    }
+  }
+
+  bool is_link_reducible(Edge_handle e) {
+    auto link = complex_.link(e);
+
+    if (link.empty())
+      return false;
+
+    if (link.is_cone())
+      return true;
+
+    if (link.num_connected_components() > 1)
+      return false;
+
+    Edge_contractor<SkBlComplex> contractor(link, link.num_vertices() - 1);
+
+    return (link.num_vertices() == 1);
+  }
+
+  double squared_edge_length(Edge_handle e) const {
+    return squared_eucl_distance(complex_.point(complex_.first_vertex(e)), complex_.point(complex_.second_vertex(e)));
+  }
+
+  double squared_eucl_distance(const Point& p1, const Point& p2) const {
+    return Geometry_trait::Squared_distance_d()(p1, p2);
+  }
+};
+
+#endif  // UTILS_EDGE_COLLAPSOR_H_
diff --git a/GudhUI/utils/Edge_contractor.h b/GudhUI/utils/Edge_contractor.h
new file mode 100644
index 00000000..45079a40
--- /dev/null
+++ b/GudhUI/utils/Edge_contractor.h
@@ -0,0 +1,97 @@
+/* This file is part of the Gudhi Library. The Gudhi library 
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++ 
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+#ifndef UTILS_EDGE_CONTRACTOR_H_
+#define UTILS_EDGE_CONTRACTOR_H_
+
+
+#include <gudhi/Skeleton_blocker_contractor.h>
+#include <gudhi/Contraction/Edge_profile.h>
+#include <gudhi/Contraction/policies/Cost_policy.h>
+
+#include <vector>
+
+/**
+ * Iteratively puts every vertex at the center of its neighbors
+ */
+template<typename SkBlComplex> class Edge_contractor {
+ private:
+  SkBlComplex& complex_;
+  unsigned num_contractions_;
+
+  /**
+   * @brief return a cost corresponding to the squared length of the edge
+   */
+  template< typename EdgeProfile> class Length_cost : public contraction::Cost_policy<EdgeProfile> {
+   public:
+    typedef typename contraction::Cost_policy<EdgeProfile>::Cost_type Cost_type;
+    typedef typename EdgeProfile::Point Point;
+
+    Cost_type operator()(const EdgeProfile& profile, const boost::optional<Point>& placement) const override {
+      Cost_type res;
+      if (!placement)
+        return res;
+      return Geometry_trait::Squared_distance_d()(profile.p0(), profile.p1());  // not working??
+    }
+  };
+
+  /**
+   * @brief return a cost corresponding to the squared length of the edge
+   */
+  template< typename EdgeProfile> class Middle_placement : public contraction::Placement_policy<EdgeProfile> {
+   public:
+    typedef typename contraction::Placement_policy<EdgeProfile>::Placement_type Placement_type;
+    typedef typename EdgeProfile::Point Point;
+
+    Placement_type operator()(const EdgeProfile& profile) const override {
+      std::vector<double> mid_coords(profile.p0().dimension(), 0);
+      for (size_t i = 0; i < profile.p0().dimension(); ++i) {
+        mid_coords[i] = (profile.p0()[i] + profile.p1()[i]) / 2.;
+      }
+      return Point(profile.p0().dimension(), mid_coords.begin(), mid_coords.end());
+    }
+  };
+
+ public:
+  typedef typename SkBlComplex::Vertex_handle Vertex_handle;
+  typedef typename SkBlComplex::Edge_handle Edge_handle;
+
+  /**
+   * @brief Modify complex to be the expansion of the k-nearest neighbor
+   * symetric graph.
+   */
+  Edge_contractor(SkBlComplex& complex, unsigned num_contractions) :
+      complex_(complex), num_contractions_(num_contractions) {
+    typedef typename contraction::Edge_profile<Complex> Profile;
+    num_contractions = (std::min)(static_cast<int>(num_contractions), static_cast<int>(complex_.num_vertices() - 1));
+    typedef typename contraction::Skeleton_blocker_contractor<Complex> Contractor;
+    Contractor contractor(complex_,
+                          new Length_cost<contraction::Edge_profile < Complex >> (),
+                          new Middle_placement<contraction::Edge_profile < Complex >> (),
+                          contraction::make_link_valid_contraction<Profile>(),
+                          contraction::make_remove_popable_blockers_visitor<Profile>());
+    contractor.contract_edges(num_contractions);
+  }
+};
+
+#endif  // UTILS_EDGE_CONTRACTOR_H_
diff --git a/GudhUI/utils/Furthest_point_epsilon_net.h b/GudhUI/utils/Furthest_point_epsilon_net.h
new file mode 100644
index 00000000..f2a216f6
--- /dev/null
+++ b/GudhUI/utils/Furthest_point_epsilon_net.h
@@ -0,0 +1,132 @@
+/* This file is part of the Gudhi Library. The Gudhi library 
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++ 
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+#ifndef UTILS_FURTHEST_POINT_EPSILON_NET_H_
+#define UTILS_FURTHEST_POINT_EPSILON_NET_H_
+
+#include <vector>
+#include <algorithm>  // for sort
+
+#include "utils/UI_utils.h"
+
+/**
+ * Computes an epsilon net with furthest point strategy.
+ */
+template<typename SkBlComplex> class Furthest_point_epsilon_net {
+ private:
+  SkBlComplex& complex_;
+  typedef typename SkBlComplex::Vertex_handle Vertex_handle;
+  typedef typename SkBlComplex::Edge_handle Edge_handle;
+
+  /**
+   * Let V be the set of vertices.
+   * Initially v0 is one arbitrarly vertex and the set V0 is {v0}.
+   * Then Vk is computed as follows.
+   * First we compute the vertex pk that is the furthest from Vk
+   * then Vk = Vk \cup pk.
+   * The radius of pk is its distance to Vk and its meeting vertex
+   * is the vertex of Vk for which this distance is achieved.
+   */
+  struct Net_filtration_vertex {
+    Vertex_handle vertex_handle;
+    Vertex_handle meeting_vertex;
+    double radius;
+
+    Net_filtration_vertex(Vertex_handle vertex_handle_,
+                          Vertex_handle meeting_vertex_,
+                          double radius_) :
+        vertex_handle(vertex_handle_), meeting_vertex(meeting_vertex_), radius(radius_) { }
+
+    bool operator<(const Net_filtration_vertex& other) const {
+      return radius < other.radius;
+    }
+  };
+
+ public:
+  std::vector<Net_filtration_vertex> net_filtration_;
+
+  /**
+   * @brief Modify complex to be the expansion of the k-nearest neighbor
+   * symetric graph.
+   */
+  Furthest_point_epsilon_net(SkBlComplex& complex) :
+      complex_(complex) {
+    if (!complex.empty()) {
+      init_filtration();
+      for (int k = 2; k < net_filtration_.size(); ++k) {
+        update_radius_value(k);
+      }
+    }
+  }
+
+  // xxx does not work if complex not full
+
+  double radius(Vertex_handle v) {
+    return net_filtration_[v.vertex].radius;
+  }
+
+ private:
+  void init_filtration() {
+    Vertex_handle v0 = *(complex_.vertex_range().begin());
+    net_filtration_.reserve(complex_.num_vertices());
+    for (auto v : complex_.vertex_range()) {
+      if (v != v0)
+        net_filtration_.push_back(Net_filtration_vertex(v,
+                                                        Vertex_handle(-1),
+                                                        squared_eucl_distance(v, v0)));
+    }
+    net_filtration_.push_back(Net_filtration_vertex(v0, Vertex_handle(-1), 1e10));
+    auto n = net_filtration_.size();
+    sort_filtration(n - 1);
+  }
+
+  void update_radius_value(int k) {
+    int n = net_filtration_.size();
+    int index_to_update = n - k;
+    for (int i = 0; i < index_to_update; ++i) {
+      net_filtration_[i].radius = (std::min)(net_filtration_[i].radius,
+                                             squared_eucl_distance(net_filtration_[i].vertex_handle,
+                                                                   net_filtration_[index_to_update].vertex_handle));
+    }
+    sort_filtration(n - k);
+  }
+
+  /**
+   * sort all i first elements.
+   */
+  void sort_filtration(int i) {
+    std::sort(net_filtration_.begin(), net_filtration_.begin() + i);
+  }
+
+  double squared_eucl_distance(Vertex_handle v1, Vertex_handle v2) const {
+    return std::sqrt(Geometry_trait::Squared_distance_d()(complex_.point(v1), complex_.point(v2)));
+  }
+
+  void print_filtration() const {
+    for (auto v : net_filtration_) {
+      std::cerr << "v=" << v.vertex_handle << "-> d=" << v.radius << std::endl;
+    }
+  }
+};
+
+#endif  // UTILS_FURTHEST_POINT_EPSILON_NET_H_
diff --git a/GudhUI/utils/Is_manifold.h b/GudhUI/utils/Is_manifold.h
new file mode 100644
index 00000000..0640ea47
--- /dev/null
+++ b/GudhUI/utils/Is_manifold.h
@@ -0,0 +1,103 @@
+/*
+ * Is_manifold.h
+ *  Created on: Jan 28, 2015
+ * This file is part of the Gudhi Library. The Gudhi library 
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++ 
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+
+#ifndef UTILS_IS_MANIFOLD_H_
+#define UTILS_IS_MANIFOLD_H_
+
+#include "utils/UI_utils.h"
+#include "utils/Edge_contractor.h"
+
+/**
+ * Iteratively tries to anticollapse smallest edge non added so far.
+ * If its link is contractible then no topological change and else possible topological change.
+ *
+ * todo do a sparsification with some parameter eps while growing
+ */
+template<typename SkBlComplex> class Is_manifold {
+ private:
+  const SkBlComplex& input_complex_;
+  typedef typename SkBlComplex::Vertex_handle Vertex_handle;
+
+ public:
+  /*
+   * return dim the maximum dimension around one simplex and res which is true if the complex is a manifold.
+   * If the complex has dimension <= 3 then if res is false, the complex is not a manifold.
+   * For d-manifold with d>=4, res may be false while the complex is a manifold.
+   */
+  Is_manifold(const SkBlComplex& input_complex, unsigned& dim, bool & res) : input_complex_(input_complex) {
+    res = true;
+    dim = -1;
+    if (!input_complex_.empty()) {
+      for (auto v : input_complex_.vertex_range()) {
+        dim = local_dimension(v);
+        break;
+      }
+      // check that the link of every vertex is a dim-1 sphere
+      for (auto v : input_complex_.vertex_range()) {
+        if (!is_k_sphere(v, dim - 1)) {
+          res = false;
+          break;
+        }
+      }
+    }
+  }
+
+ private:
+  unsigned local_dimension(Vertex_handle v) {
+    unsigned dim = 0;
+    for (const auto& s : input_complex_.star_simplex_range(v))
+      dim = (std::max)(dim, (unsigned) s.dimension());
+    return dim;
+  }
+
+  bool is_k_sphere(Vertex_handle v, int k) {
+    auto link = input_complex_.link(v);
+    Edge_contractor<Complex> contractor(link, link.num_vertices() - 1);
+    return (is_sphere_simplex(link) == k);
+  }
+
+  // A minimal sphere is a complex that contains vertices v1...vn and all faces
+  // made upon this set except the face {v1,...,vn}
+  // return -2 if not a minimal sphere
+  // and d otherwise if complex is a d minimal sphere
+
+  template<typename SubComplex>
+  int is_sphere_simplex(const SubComplex& complex) {
+    if (complex.empty()) return -1;
+    if (complex.num_blockers() != 1) return -2;
+
+    // necessary and sufficient condition : there exists a unique blocker that passes through all vertices
+    auto first_blocker = *(complex.const_blocker_range().begin());
+
+    if (first_blocker->dimension() + 1 != complex.num_vertices())
+      return -2;
+    else
+      return (first_blocker->dimension() - 1);
+  }
+};
+
+#endif  // UTILS_IS_MANIFOLD_H_
diff --git a/GudhUI/utils/K_nearest_builder.h b/GudhUI/utils/K_nearest_builder.h
new file mode 100644
index 00000000..7be0a4f4
--- /dev/null
+++ b/GudhUI/utils/K_nearest_builder.h
@@ -0,0 +1,90 @@
+/* This file is part of the Gudhi Library. The Gudhi library 
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++ 
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+#ifndef UTILS_K_NEAREST_BUILDER_H_
+#define UTILS_K_NEAREST_BUILDER_H_
+
+#include <CGAL/Euclidean_distance.h>
+#include <CGAL/Orthogonal_k_neighbor_search.h>
+#include <CGAL/Search_traits_d.h>
+#include <CGAL/Search_traits_adapter.h>
+#include <CGAL/property_map.h>
+
+#include <unordered_map>
+#include <list>
+#include <utility>
+
+#include "utils/UI_utils.h"
+#include "model/Complex_typedefs.h"
+
+template<typename SkBlComplex> class K_nearest_builder {
+ private:
+  typedef Geometry_trait Kernel;
+  typedef Point Point_d;
+  typedef std::pair<Point_d, unsigned> Point_d_with_id;
+  typedef CGAL::Search_traits_d<Kernel> Traits_base;
+  typedef CGAL::Search_traits_adapter<Point_d_with_id, CGAL::First_of_pair_property_map<Point_d_with_id>,
+      Traits_base> Traits;
+  typedef CGAL::Orthogonal_k_neighbor_search<Traits> Neighbor_search;
+  typedef Neighbor_search::Tree Tree;
+  typedef Neighbor_search::Distance Distance;
+
+  SkBlComplex& complex_;
+
+ public:
+  /**
+   * @brief Modify complex to be the expansion of the k-nearest neighbor
+   * symetric graph.
+   */
+  K_nearest_builder(SkBlComplex& complex, unsigned k) : complex_(complex) {
+    complex.keep_only_vertices();
+    compute_edges(k);
+  }
+
+ private:
+  double squared_eucl_distance(const Point& p1, const Point& p2) const {
+    return Geometry_trait::Squared_distance_d()(p1, p2);
+  }
+
+  void compute_edges(unsigned k) {
+    std::list<Point_d_with_id> points_with_id;
+    for (auto v : complex_.vertex_range()) {
+      Point_d_with_id point_v(complex_.point(v), v.vertex);
+      points_with_id.push_back(point_v);
+    }
+
+    Tree tree(points_with_id.begin(), points_with_id.end());
+
+    typedef typename SkBlComplex::Vertex_handle Vertex_handle;
+    for (auto p : complex_.vertex_range()) {
+      Neighbor_search search(tree, complex_.point(p), k + 1);
+      for (auto it = ++search.begin(); it != search.end(); ++it) {
+        Vertex_handle q(std::get<1>(it->first));
+        if (p != q && complex_.contains_vertex(p) && complex_.contains_vertex(q))
+          complex_.add_edge(p, q);
+      }
+    }
+  }
+};
+
+#endif  // UTILS_K_NEAREST_BUILDER_H_
diff --git a/GudhUI/utils/Lloyd_builder.h b/GudhUI/utils/Lloyd_builder.h
new file mode 100644
index 00000000..18ec9fac
--- /dev/null
+++ b/GudhUI/utils/Lloyd_builder.h
@@ -0,0 +1,91 @@
+/* This file is part of the Gudhi Library. The Gudhi library 
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++ 
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+#ifndef UTILS_LLOYD_BUILDER_H_
+#define UTILS_LLOYD_BUILDER_H_
+
+#include <vector>
+#include <list>
+
+/**
+ * Iteratively puts every vertex at the center of its neighbors
+ */
+template<typename SkBlComplex> class Lloyd_builder {
+ private:
+  SkBlComplex& complex_;
+  int dim;
+
+ public:
+  typedef typename SkBlComplex::Vertex_handle Vertex_handle;
+
+  /**
+   * @brief Modify complex to be the expansion of the k-nearest neighbor
+   * symetric graph.
+   */
+  Lloyd_builder(SkBlComplex& complex, unsigned num_iterations) : complex_(complex), dim(-1) {
+    if (!complex_.empty()) {
+      dim = get_dimension();
+      while (num_iterations--) {
+        std::list<Point> new_points;
+        for (auto v : complex.vertex_range())
+          new_points.push_back(barycenter_neighbors(v));
+
+        auto new_points_it = new_points.begin();
+        for (auto v : complex.vertex_range())
+          complex_.point(v) = *(new_points_it++);
+      }
+    }
+  }
+
+ private:
+  int get_dimension() {
+    assert(!complex_.empty());
+    for (auto v : complex_.vertex_range())
+      return complex_.point(v).dimension();
+    return -1;
+  }
+
+  Point barycenter_neighbors(Vertex_handle v) const {
+    if (complex_.degree(v) == 0)
+      return complex_.point(v);
+
+    std::vector<double> res(dim, 0);
+    unsigned num_points = 0;
+    for (auto nv : complex_.vertex_range(v)) {
+      ++num_points;
+      const Point& point = complex_.point(nv);
+      assert(point.dimension() == dim);
+      for (int i = 0; i < point.dimension(); ++i)
+        res[i] += point[i];
+    }
+    for (auto& x : res)
+      x /= num_points;
+    return Point(dim, res.begin(), res.end());
+  }
+
+  double squared_eucl_distance(const Point& p1, const Point& p2) const {
+    return Geometry_trait::Squared_distance_d()(p1, p2);
+  }
+};
+
+#endif  // UTILS_LLOYD_BUILDER_H_
diff --git a/GudhUI/utils/MClock.h b/GudhUI/utils/MClock.h
new file mode 100644
index 00000000..e8d8918a
--- /dev/null
+++ b/GudhUI/utils/MClock.h
@@ -0,0 +1,70 @@
+/* This file is part of the Gudhi Library. The Gudhi library 
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++ 
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+#ifndef UTILS_MCLOCK_H_
+#define UTILS_MCLOCK_H_
+
+#include <sys/time.h>
+
+class MClock {
+ public:
+  MClock() {
+    end_called = false;
+    begin();
+  }
+
+  void begin() const {
+    end_called = false;
+    gettimeofday(&startTime, NULL);
+  }
+
+  void end() const {
+    end_called = true;
+    gettimeofday(&endTime, NULL);
+  }
+
+  friend std::ostream& operator<<(std::ostream& stream, const MClock& clock) {
+    // if(!clock.end_called) clock.end();
+    if (!clock.end_called) {
+      stream << "end not called";
+    } else {
+      long totalTime = (clock.endTime.tv_sec - clock.startTime.tv_sec) * 1000000L;
+      totalTime += (clock.endTime.tv_usec - clock.startTime.tv_usec);
+      stream << clock.num_seconds() << "s";
+    }
+    return stream;
+  }
+
+  double num_seconds() const {
+    if (!end_called) end();
+    long totalTime = (endTime.tv_sec - startTime.tv_sec) * 1000000L;
+    totalTime += (endTime.tv_usec - startTime.tv_usec);
+    return (totalTime / 1000L) / static_cast<double>(1000);
+  }
+
+ private:
+  mutable struct timeval startTime, endTime;
+  mutable bool end_called;
+};
+
+#endif  // UTILS_MCLOCK_H_
diff --git a/GudhUI/utils/Persistence_compute.h b/GudhUI/utils/Persistence_compute.h
new file mode 100644
index 00000000..97165490
--- /dev/null
+++ b/GudhUI/utils/Persistence_compute.h
@@ -0,0 +1,91 @@
+/* This file is part of the Gudhi Library. The Gudhi library 
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++ 
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+
+#ifndef UTILS_PERSISTENCE_COMPUTE_H_
+#define UTILS_PERSISTENCE_COMPUTE_H_
+
+#include <gudhi/graph_simplicial_complex.h>
+#include <gudhi/Simplex_tree.h>
+#include <gudhi/distance_functions.h>
+#include <gudhi/Persistent_cohomology.h>
+
+#include <vector>
+
+struct Persistence_params {
+  int p;
+  double threshold;
+  int max_dim;
+  double min_pers;
+
+  Persistence_params(int p_, double th_, int max_dim_ = 10, double min_pers_ = 0)
+      : p(p_), threshold(th_), max_dim(max_dim_), min_pers(min_pers_) { }
+};
+
+/**
+ * Show persistence into output stream
+ */
+template<typename SkBlComplex> class Persistence_compute {
+ public:
+  typedef typename SkBlComplex::Vertex_handle Vertex_handle;
+  typedef typename SkBlComplex::Edge_handle Edge_handle;
+
+  /**
+   * @brief Compute persistence
+   * parameters :
+   * unsigned dim_max
+   * double threshold
+   * int p for coefficient Z_p
+   */
+  Persistence_compute(SkBlComplex& complex, std::ostream& stream, const Persistence_params& params) {
+    // for now everything is copied, todo boost adapt iterators to points of SkBlComplex instead of copying to an
+    // initial vector
+    typedef std::vector<double> Point_t;
+    std::vector< Point_t > points;
+    points.reserve(complex.num_vertices());
+    for (auto v : complex.vertex_range()) {
+      const auto & pt = complex.point(v);
+      Point_t pt_to_add(pt.cartesian_begin(), pt.cartesian_end());
+      points.emplace_back(std::move(pt_to_add));
+    }
+
+
+    Graph_t prox_graph = compute_proximity_graph(points, params.threshold, euclidean_distance<Point_t>);
+    Gudhi::Simplex_tree<> st;
+    st.insert_graph(prox_graph);
+    st.expansion(params.max_dim);
+
+    Gudhi::persistent_cohomology::Persistent_cohomology< Gudhi::Simplex_tree<>,
+        Gudhi::persistent_cohomology::Field_Zp > pcoh(st);
+    // initializes the coefficient field for homology
+    pcoh.init_coefficients(params.p);
+    // put params.min_pers
+    pcoh.compute_persistent_cohomology(params.min_pers);
+    stream << "persistence: \n";
+    stream << "p dimension birth death: \n";
+
+    pcoh.output_diagram(stream);
+  }
+};
+
+#endif  // UTILS_PERSISTENCE_COMPUTE_H_
diff --git a/GudhUI/utils/Rips_builder.h b/GudhUI/utils/Rips_builder.h
new file mode 100644
index 00000000..b22f4db6
--- /dev/null
+++ b/GudhUI/utils/Rips_builder.h
@@ -0,0 +1,69 @@
+/* This file is part of the Gudhi Library. The Gudhi library 
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++ 
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+#ifndef UTILS_RIPS_BUILDER_H_
+#define UTILS_RIPS_BUILDER_H_
+
+#include <boost/iterator/iterator_facade.hpp>
+
+#include <CGAL/Euclidean_distance.h>
+#include <CGAL/Orthogonal_k_neighbor_search.h>
+#include <CGAL/Search_traits_d.h>
+
+#include "utils/UI_utils.h"
+#include "model/Complex_typedefs.h"
+
+template<typename SkBlComplex> class Rips_builder {
+ private:
+  SkBlComplex& complex_;
+
+ public:
+  /**
+   * @brief Modify complex to be the Rips complex
+   * of its points with offset alpha.
+   */
+  Rips_builder(SkBlComplex& complex, double alpha) : complex_(complex) {
+    complex.keep_only_vertices();
+    if (alpha <= 0) return;
+    compute_edges(alpha);
+  }
+
+ private:
+  double squared_eucl_distance(const Point& p1, const Point& p2) const {
+    return Geometry_trait::Squared_distance_d()(p1, p2);
+  }
+
+  void compute_edges(double alpha) {
+    auto vertices = complex_.vertex_range();
+    for (auto p = vertices.begin(); p != vertices.end(); ++p) {
+      std::cout << *p << " ";
+      std::cout.flush();
+      for (auto q = p; ++q != vertices.end(); /**/)
+        if (squared_eucl_distance(complex_.point(*p), complex_.point(*q)) < 4 * alpha * alpha)
+          complex_.add_edge(*p, *q);
+    }
+    std::cout << std::endl;
+  }
+};
+
+#endif  // UTILS_RIPS_BUILDER_H_
diff --git a/GudhUI/utils/UI_utils.h b/GudhUI/utils/UI_utils.h
new file mode 100644
index 00000000..9cc209d3
--- /dev/null
+++ b/GudhUI/utils/UI_utils.h
@@ -0,0 +1,45 @@
+/* This file is part of the Gudhi Library. The Gudhi library 
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++ 
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+#ifndef UTILS_UI_UTILS_H_
+#define UTILS_UI_UTILS_H_
+
+#define UIDBG_VERBOSE
+
+#ifdef UIDBG_VERBOSE
+#define UIDBG(a) std::cerr << "UIDBG: " << (a) << std::endl
+#define UIDBGMSG(a, b) std::cerr << "UIDBG: " << a << b << std::endl
+#define UIDBGVALUE(a) std::cerr << "UIDBG: " <<  #a << ": " << a << std::endl
+#define UIDBGCONT(a) std::cerr << "UIDBG: container " << #a << " -> "; for (auto x : a) std::cerr << x << ","; std::cerr << std::endl }
+#else
+// #define DBG(a) a
+// #define DBGMSG(a, b) b
+// #define DBGVALUE(a) a
+// #define DBGCONT(a) a
+#define UIDBG(a)
+#define UIDBGMSG(a, b)
+#define UIDBGVALUE(a)
+#define UIDBGCONT(a)
+#endif
+
+#endif  // UTILS_UI_UTILS_H_
diff --git a/GudhUI/utils/Vertex_collapsor.h b/GudhUI/utils/Vertex_collapsor.h
new file mode 100644
index 00000000..2b36cb3a
--- /dev/null
+++ b/GudhUI/utils/Vertex_collapsor.h
@@ -0,0 +1,88 @@
+/* This file is part of the Gudhi Library. The Gudhi library 
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++ 
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+#ifndef UTILS_VERTEX_COLLAPSOR_H_
+#define UTILS_VERTEX_COLLAPSOR_H_
+
+#include <list>
+
+#include "utils/Edge_contractor.h"
+#include "utils/Furthest_point_epsilon_net.h"
+#include "utils/UI_utils.h"
+
+/**
+ * Iteratively puts every vertex at the center of its neighbors
+ */
+template<typename SkBlComplex> class Vertex_collapsor {
+ private:
+  SkBlComplex& complex_;
+  size_t num_collapses_;
+
+ public:
+  typedef typename SkBlComplex::Vertex_handle Vertex_handle;
+  typedef typename SkBlComplex::Edge_handle Edge_handle;
+
+  /**
+   * @brief Modify complex to be the expansion of the k-nearest neighbor
+   * symetric graph.
+   */
+  Vertex_collapsor(SkBlComplex& complex, size_t num_collapses) :
+      complex_(complex), num_collapses_(num_collapses) {
+    // std::list<Vertex_handle> vertices;
+    // vertices.insert(vertices.begin(),complex_.vertex_range().begin(),complex_.vertex_range().end());
+    // UIDBG("Collapse vertices");
+    // collapse_vertices(vertices);
+
+    std::list<Vertex_handle> vertices;
+
+    UIDBG("Compute eps net");
+    Furthest_point_epsilon_net<Complex> eps_net(complex_);
+
+    for (auto vh : eps_net.net_filtration_)
+      vertices.push_back(vh.vertex_handle);
+
+    UIDBG("Collapse vertices");
+    collapse_vertices(vertices);
+  }
+
+ private:
+  void collapse_vertices(std::list<Vertex_handle>& vertices) {
+    while (!vertices.empty() && num_collapses_--) {
+      Vertex_handle current_vertex = vertices.front();
+      vertices.pop_front();
+      if (is_link_reducible(current_vertex))
+        complex_.remove_vertex(current_vertex);
+    }
+  }
+
+  bool is_link_reducible(Vertex_handle v) {
+    auto link = complex_.link(v);
+    if (link.empty()) return false;
+    if (link.is_cone()) return true;
+    if (link.num_connected_components() > 1) return false;
+    Edge_contractor<Complex> contractor(link, link.num_vertices() - 1);
+    return (link.num_vertices() == 1);
+  }
+};
+
+#endif  // UTILS_VERTEX_COLLAPSOR_H_
diff --git a/GudhUI/utils/homsimpl b/GudhUI/utils/homsimpl
new file mode 100755
index 00000000..12227502
--- /dev/null
+++ b/GudhUI/utils/homsimpl
diff --git a/GudhUI/view/Color.h b/GudhUI/view/Color.h
new file mode 100644
index 00000000..ba0592e1
--- /dev/null
+++ b/GudhUI/view/Color.h
@@ -0,0 +1,35 @@
+/* This file is part of the Gudhi Library. The Gudhi library 
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++ 
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+#ifndef VIEW_COLOR_H_
+#define VIEW_COLOR_H_
+
+struct Color {
+  double r;
+  double g;
+  double b;
+
+  Color(double r_, double g_, double b_) : r(r_), g(g_), b(b_) { }
+};
+
+#endif  // VIEW_COLOR_H_
diff --git a/GudhUI/view/FirstCoordProjector.h b/GudhUI/view/FirstCoordProjector.h
new file mode 100644
index 00000000..a4027b7f
--- /dev/null
+++ b/GudhUI/view/FirstCoordProjector.h
@@ -0,0 +1,42 @@
+/* This file is part of the Gudhi Library. The Gudhi library 
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++ 
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+#ifndef VIEW_FIRSTCOORDPROJECTOR_H_
+#define VIEW_FIRSTCOORDPROJECTOR_H_
+
+#include "utils/UI_utils.h"
+#include "Projector3D.h"
+
+class FirstCoordProjector3D : public Projector3D {
+  typedef Projector3D::Point Point;
+  typedef Projector3D::Point_3 Point_3;
+
+  Point_3 operator()(const Point& p) const {
+    if (p.dimension() >= 3)
+    return Point_3(p.x(), p.y(), p.z());
+    else if  (p.dimension() >= 2)
+    return Point_3(p.x(), p.y(), 0.0);
+  }
+};
+
+#endif  // VIEW_FIRSTCOORDPROJECTOR_H_
diff --git a/GudhUI/view/Projector3D.h b/GudhUI/view/Projector3D.h
new file mode 100644
index 00000000..2a756541
--- /dev/null
+++ b/GudhUI/view/Projector3D.h
@@ -0,0 +1,39 @@
+/* This file is part of the Gudhi Library. The Gudhi library 
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++ 
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+#ifndef VIEW_PROJECTOR3D_H_
+#define VIEW_PROJECTOR3D_H_
+
+#include "model/Complex_typedefs.h"
+
+class Projector3D {
+ public:
+  typedef Geometry_trait::Point Point;
+  typedef Geometry_trait::Point_3 Point_3;
+
+  virtual Point_3 operator()(const Point&) const = 0;
+
+  virtual ~Projector3D() { }
+};
+
+#endif  // VIEW_PROJECTOR3D_H_
diff --git a/GudhUI/view/View_parameter.h b/GudhUI/view/View_parameter.h
new file mode 100644
index 00000000..9805abc2
--- /dev/null
+++ b/GudhUI/view/View_parameter.h
@@ -0,0 +1,151 @@
+/* This file is part of the Gudhi Library. The Gudhi library 
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++ 
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+#ifndef VIEW_VIEW_PARAMETER_H_
+#define VIEW_VIEW_PARAMETER_H_
+
+#include <iostream>
+
+/**
+ * Different parameters for the view such as the camera angle,
+ * the light, options for vertices/edges/triangles.
+ */
+class View_parameter {
+ public:
+  bool light;
+  bool relative_light;
+
+  double size_vertices;
+  double size_edges;
+  double light_edges;  // in 0-1
+  double light_triangles;  // in 0-1
+
+  /**
+   * light angle
+   */
+  double theta;
+  double phi;
+
+  enum VERTEX_MODE {
+    V_NONE, V_SIMPLE, V_COUNT
+  };
+
+  enum EDGE_MODE {
+    E_NONE, E_SIMPLE, E_COUNT
+  };
+
+  enum TRIANGLE_MODE {
+    T_NONE, T_SIMPLE, T_COUNT
+  };
+
+  VERTEX_MODE vertex_mode;
+  EDGE_MODE edge_mode;
+  TRIANGLE_MODE triangle_mode;
+
+  void change_vertex_mode() {
+    int current_value = vertex_mode;
+    vertex_mode = static_cast<VERTEX_MODE> (++current_value % V_COUNT);
+    std::cout << "Vertex mode : ";
+    switch (vertex_mode) {
+      case V_NONE:
+        std::cout << "empty\n";
+        break;
+      case V_SIMPLE:
+        std::cout << "simple\n";
+        break;
+      default:
+        break;
+    }
+  }
+
+  void change_vertex_mode(int new_mode) {
+    vertex_mode = static_cast<VERTEX_MODE> (new_mode % V_COUNT);
+  }
+
+  void change_edge_mode() {
+    int current_value = edge_mode;
+    edge_mode = static_cast<EDGE_MODE> (++current_value % E_COUNT);
+  }
+
+  void change_edge_mode(int new_mode) {
+    edge_mode = static_cast<EDGE_MODE> (new_mode % E_COUNT);
+  }
+
+  void change_triangle_mode() {
+    int current_value = triangle_mode;
+    triangle_mode = static_cast<TRIANGLE_MODE> (++current_value % T_COUNT);
+  }
+
+  View_parameter() {
+    light = true;
+    relative_light = true;
+    vertex_mode = V_SIMPLE;
+    edge_mode = E_SIMPLE;
+    triangle_mode = T_NONE;
+
+    size_vertices = 3;
+    size_edges = 2;
+
+    light_edges = 0.3;
+    light_triangles = 0.85;
+    theta = 0;
+    phi = 0;
+  }
+
+  friend std::ostream& operator<<(std::ostream& stream, const View_parameter& param) {
+    stream << param.light << " ";
+    stream << param.relative_light << " ";
+    stream << param.vertex_mode << " ";
+    stream << param.edge_mode << " ";
+    stream << param.triangle_mode << " ";
+    stream << param.size_vertices << " ";
+    stream << param.size_edges << " ";
+    stream << param.light_edges << " ";
+    stream << param.light_triangles << " ";
+    stream << param.theta << " ";
+    stream << param.phi << " ";
+    return stream;
+  }
+
+  friend std::istream& operator>>(std::istream& stream, View_parameter& param) {
+    stream >> param.light;
+    stream >> param.relative_light;
+    int a;
+    stream >> a;
+    param.vertex_mode = static_cast<VERTEX_MODE> (a % V_COUNT);
+    stream >> a;
+    param.edge_mode = static_cast<EDGE_MODE> (a % E_COUNT);
+    stream >> a;
+    param.triangle_mode = static_cast<TRIANGLE_MODE> (a % T_COUNT);
+    stream >> a;
+    stream >> param.size_vertices;
+    stream >> param.size_edges;
+    stream >> param.light_edges;
+    stream >> param.light_triangles;
+    stream >> param.theta;
+    stream >> param.phi;
+    return stream;
+  }
+};
+
+#endif  // VIEW_VIEW_PARAMETER_H_
diff --git a/GudhUI/view/Viewer.cpp b/GudhUI/view/Viewer.cpp
new file mode 100644
index 00000000..c6c2b345
--- /dev/null
+++ b/GudhUI/view/Viewer.cpp
@@ -0,0 +1,186 @@
+/* This file is part of the Gudhi Library. The Gudhi library 
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++ 
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+#include "Viewer.h"
+#include "utils/UI_utils.h"
+
+Viewer::Viewer(QWidget* parent) : QGLViewer(QGLFormat(QGL::SampleBuffers), parent), instructor(0), theta(0), phi(0) { }
+
+void Viewer::set_instructor(Viewer_instructor* instructor_) {
+  instructor = instructor_;
+}
+
+void Viewer::show_entire_scene() {
+  this->showEntireScene();
+}
+
+void Viewer::draw() {
+  instructor->give_instructions();
+}
+
+void Viewer::set_bounding_box(const Point_3 & lower_left, const Point_3 & upper_right) {
+  this->camera()->setSceneBoundingBox(qglviewer::Vec(lower_left[0], lower_left[1], lower_left[2]),
+                                      qglviewer::Vec(upper_right[0], upper_right[1], upper_right[2]));
+}
+
+void Viewer::update_GL() {
+  this->updateGL();
+}
+
+void Viewer::init_scene() {
+  this->setBackgroundColor(Qt::white);
+  ::glEnable(GL_LINE_SMOOTH);
+  init_light();
+}
+
+void Viewer::init_light() {
+  ::glLightModeli(GL_LIGHT_MODEL_TWO_SIDE, GL_TRUE);
+}
+
+void Viewer::set_light() {
+  if (theta >= 0 && phi >= 0) {
+    const GLfloat pos[4] = {static_cast<float> (sin(phi) * cos(theta)),
+                            static_cast<float> (sin(phi) * sin(theta)),
+                            static_cast<float> (cos(phi)), 0.};
+    glLightfv(GL_LIGHT0, GL_POSITION, pos);
+  }
+}
+
+void Viewer::set_light_direction(double theta_, double phi_) {
+  theta = theta_;
+  phi = phi_;
+}
+
+/**
+ * set the light in the direction of the observer
+ */
+void Viewer::set_light_direction() {
+  theta = -1;
+  phi = -1;
+}
+
+void Viewer::postSelection(const QPoint& point) {
+  bool found;
+
+  auto vec = this->camera()->pointUnderPixel(point, found);
+
+  if (found) {
+    Point_3 position(vec[0], vec[1], vec[2]);
+    emit(click(position));
+  }
+}
+
+////////////////////////
+// draw
+////////////////////////
+
+void Viewer::set_size_point(double size_points) {
+  ::glPointSize(size_points);
+}
+
+void Viewer::draw_point(const Point_3& p, const Color& color, double size_points) {
+  ::glColor3f(color.r, color.g, color.b);
+  ::glDisable(GL_LIGHTING);
+  ::glEnable(GL_POINT_SMOOTH);
+  ::glPointSize(size_points);
+  ::glBegin(GL_POINTS);
+  ::glVertex3d(p.x(), p.y(), p.z());
+  ::glEnd();
+  ::glDisable(GL_POINT_SMOOTH);
+}
+
+void Viewer::begin_draw_points(double size, bool light) {
+  light ? glEnable(GL_LIGHTING) : glDisable(GL_LIGHTING);
+  ::glEnable(GL_POINT_SMOOTH);
+  ::glPointSize(size);
+  ::glBegin(GL_POINTS);
+}
+
+void Viewer::set_color(const Color& color) {
+  ::glColor3f(color.r, color.g, color.b);
+}
+
+void Viewer::draw_points(const Point_3 & point) {
+  ::glVertex3d(point.x(), point.y(), point.z());
+}
+
+void Viewer::end_draw_points() {
+  ::glEnd();
+  ::glDisable(GL_POINT_SMOOTH);
+}
+
+void Viewer::draw_edge(const Point_3 &a, const Point_3 &b, const Color& color, double size) {
+  ::glColor3f(color.r, color.g, color.b);
+  ::glPointSize(3.0);
+  ::glLineWidth(size);
+  ::glBegin(GL_LINES);
+  ::glVertex3f(a.x(), a.y(), a.z());
+  ::glVertex3f(b.x(), b.y(), b.z());
+  ::glEnd();
+}
+
+void Viewer::begin_draw_edges(double size, bool light) {
+  ::glLineWidth(size);
+  ::glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
+  ::glEnable(GL_POLYGON_OFFSET_LINE);
+  ::glPolygonOffset(3.0f, -3.0f);
+  light ? glEnable(GL_LIGHTING) : glDisable(GL_LIGHTING);
+  ::glBegin(GL_LINES);
+}
+
+void Viewer::draw_edges(const Point_3 &a, const Point_3 &b) {
+  ::glVertex3f(a.x(), a.y(), a.z());
+  ::glVertex3f(b.x(), b.y(), b.z());
+}
+
+void Viewer::end_draw_edges() {
+  ::glEnd();
+}
+
+void Viewer::begin_draw_triangles(double size, bool light, bool transparent) {
+  if (transparent) {
+    ::glEnable(GL_BLEND);
+    ::glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+  }
+  ::glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
+  ::glEnable(GL_POLYGON_OFFSET_FILL);
+  ::glPolygonOffset(3.0f, -3.0f);
+  light ? glEnable(GL_LIGHTING) : glDisable(GL_LIGHTING);
+  ::glBegin(GL_TRIANGLES);
+}
+
+void Viewer::draw_triangles(const Point_3& p1, const Point_3& p2, const Point_3& p3) {
+  if (!CGAL::collinear(p1, p2, p3)) {
+    auto triangle_normal = CGAL::unit_normal(p1, p2, p3);
+    ::glNormal3d(triangle_normal.x(), triangle_normal.y(), triangle_normal.z());
+    ::glVertex3d(p1.x(), p1.y(), p1.z());
+    ::glVertex3d(p2.x(), p2.y(), p2.z());
+    ::glVertex3d(p3.x(), p3.y(), p3.z());
+  }
+}
+
+void Viewer::end_draw_triangles() {
+  ::glEnd();
+}
+
+#include "Viewer.moc"
diff --git a/GudhUI/view/Viewer.h b/GudhUI/view/Viewer.h
new file mode 100644
index 00000000..319c8e04
--- /dev/null
+++ b/GudhUI/view/Viewer.h
@@ -0,0 +1,120 @@
+/* This file is part of the Gudhi Library. The Gudhi library 
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++ 
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+#ifndef VIEW_VIEWER_H_
+#define VIEW_VIEWER_H_
+
+// Workaround for moc-qt4 not parsing boost headers
+#include <CGAL/config.h>
+
+#include <QGLViewer/qglviewer.h>
+
+#include <vector>
+
+#include "View_parameter.h"
+#include "model/Complex_typedefs.h"
+#include "Color.h"
+#include "Viewer_instructor.h"
+
+class Viewer_instructor;
+
+class Viewer : public QGLViewer {
+  Q_OBJECT
+
+  Viewer_instructor * instructor;
+
+  /**
+   * light angles
+   */
+  double theta, phi;
+  typedef Complex::GT Gudhi_kernel;
+  typedef Gudhi_kernel::Point_3 Point_3;
+
+ public:
+  Viewer(QWidget* parent);
+
+  void set_instructor(Viewer_instructor* instructor_);
+
+  void show_entire_scene();
+
+  void draw();
+
+  void set_bounding_box(const Point_3 & lower_left, const Point_3 & upper_right);
+
+  void update_GL();
+
+  void init_scene();
+
+  void init_light();
+
+  void set_light();
+
+  void set_light_direction(double theta, double phi);
+
+  /**
+   * set the light in the direction of the observer
+   */
+  void set_light_direction();
+
+ protected:
+  virtual void postSelection(const QPoint& point);
+
+ public:
+  ////////////////////////
+  // draw
+  ////////////////////////
+  void set_size_point(double size_points);
+
+  void set_color(const Color& color);
+
+  void draw_point(const Point_3& p, const Color& color, double size_points);
+
+  void begin_draw_points(double size, bool light = false);
+
+  void draw_points(const Point_3 & point);
+
+  void end_draw_points();
+
+  void draw_edge(const Point_3 &a, const Point_3 &b, const Color& color, double size);
+
+  void begin_draw_edges(double size, bool light = false);
+
+  void draw_edges(const Point_3 &a, const Point_3 &b);
+
+  void end_draw_edges();
+
+  void begin_draw_triangles(double size, bool light, bool transparent = false);
+
+  void draw_triangles(const Point_3& p1, const Point_3& p2, const Point_3& p3);
+
+  // todo remove
+  void draw_triangles(const std::vector<Point_3*>& points);
+
+  void end_draw_triangles();
+
+
+ signals:
+  void click(const Point_3& position);
+};
+
+#endif  // VIEW_VIEWER_H_
diff --git a/GudhUI/view/Viewer_instructor.cpp b/GudhUI/view/Viewer_instructor.cpp
new file mode 100644
index 00000000..1ddd4d8b
--- /dev/null
+++ b/GudhUI/view/Viewer_instructor.cpp
@@ -0,0 +1,192 @@
+/* This file is part of the Gudhi Library. The Gudhi library 
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++ 
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+#include <utility>
+
+#include "Viewer_instructor.h"
+#include "utils/UI_utils.h"
+#include "FirstCoordProjector.h"
+
+Viewer_instructor::Viewer_instructor(QWidget* parent,
+                                     Viewer* viewer,
+                                     const Complex& mesh
+                                     )
+    : viewer_(viewer), mesh_(mesh), projector_(new FirstCoordProjector3D()) {
+  viewer_->set_instructor(this);
+}
+
+void Viewer_instructor::initialize_bounding_box() {
+  auto pair_bounding_box = compute_bounding_box_corners();
+  viewer_->set_bounding_box(proj(pair_bounding_box.first), proj(pair_bounding_box.second));
+  viewer_->init_scene();
+}
+
+std::pair<Complex::Point, Complex::Point> Viewer_instructor::compute_bounding_box_corners() {
+  if (mesh_.empty()) {
+    return std::make_pair(Point(-1, -1, -1, 1), Point(1, 1, 1, 1));
+  } else {
+    double x_min = 1e10;
+    double y_min = 1e10;
+    double z_min = 1e10;
+    double x_max = -1e10;
+    double y_max = -1e10;
+    double z_max = -1e10;
+    for (auto vi : mesh_.vertex_range()) {
+      auto pt = proj(mesh_.point(vi));
+      x_min = (std::min)(x_min, pt.x());
+      y_min = (std::min)(y_min, pt.y());
+      z_min = (std::min)(z_min, pt.z());
+
+      x_max = (std::max)(x_max, pt.x());
+      y_max = (std::max)(y_max, pt.y());
+      z_max = (std::max)(z_max, pt.z());
+    }
+    return std::make_pair(Point(x_min, y_min, z_min, 1.),
+                          Point(x_max, y_max, z_max, 1.));
+  }
+}
+
+void Viewer_instructor::show_entire_scene() {
+  viewer_->show_entire_scene();
+}
+
+const qglviewer::Camera* Viewer_instructor::camera() const {
+  return viewer_->camera();
+}
+
+int
+Viewer_instructor::width() const {
+  return viewer_->width();
+}
+
+int
+Viewer_instructor::height() const {
+  return viewer_->height();
+}
+
+/**
+ * to change display parameters
+ */
+View_parameter& Viewer_instructor::view_params() {
+  return view_params_;
+}
+
+void
+Viewer_instructor::give_instructions() {
+  if (view_params_.relative_light)
+    viewer_->set_light_direction();
+  else
+    viewer_->set_light_direction(view_params_.theta, view_params_.phi);
+  viewer_->set_light();
+
+  if (view_params_.edge_mode) draw_edges();
+  if (view_params_.triangle_mode) draw_triangles();
+  if (view_params_.vertex_mode) draw_points();
+}
+
+void Viewer_instructor::draw_edges() {
+  viewer_->begin_draw_edges(view_params_.size_edges, false);
+
+  for (auto edge : mesh_.edge_range()) {
+    set_color_edge(edge);
+    const Point& a = mesh_.point(mesh_.first_vertex(edge));
+    const Point& b = mesh_.point(mesh_.second_vertex(edge));
+    viewer_->draw_edges(proj(a), proj(b));
+  }
+
+  viewer_->end_draw_edges();
+}
+
+void Viewer_instructor::draw_triangles() {
+  const double size_triangles = 1.0;
+  viewer_->begin_draw_triangles(size_triangles, view_params_.light);
+
+  for (const auto& fit : mesh_.triangle_range()) {
+    set_color_triangle(fit);
+    if (view_params_.triangle_mode) {
+      auto fit_it = fit.begin();
+      const Point& p1 = mesh_.point(*fit_it);
+      const Point& p2 = mesh_.point(*(++fit_it));
+      const Point& p3 = mesh_.point(*(++fit_it));
+      viewer_->draw_triangles(proj(p1), proj(p2), proj(p3));
+    }
+  }
+  viewer_->end_draw_triangles();
+}
+
+void Viewer_instructor::draw_points() {
+  viewer_->begin_draw_points(view_params_.size_vertices);
+  for (auto vi : mesh_.vertex_range()) {
+    viewer_->set_size_point(view_params_.size_vertices);
+    set_color_vertex(vi);
+    viewer_->draw_points(proj(mesh_.point(vi)));
+  }
+  viewer_->end_draw_points();
+}
+
+void Viewer_instructor::draw_edge(const Point&, const Point&) { }
+
+void Viewer_instructor::draw_point(const Point&) { }
+
+/**
+ * set the right color of vertex/edge/triangle considering the view_params choice
+ */
+void Viewer_instructor::set_color_vertex(Vertex_handle vh) {
+  viewer_->set_color(Color(view_params_.light_edges, view_params_.light_edges, view_params_.light_edges));
+}
+
+void Viewer_instructor::set_color_edge(Edge_handle eh) {
+  viewer_->set_color(Color(view_params_.light_edges, view_params_.light_edges, view_params_.light_edges));
+}
+
+void Viewer_instructor::set_color_triangle(const Simplex& triangle) {
+  viewer_->set_color(Color(view_params_.light_triangles, view_params_.light_triangles, view_params_.light_triangles));
+}
+
+Viewer_instructor::Point_3
+Viewer_instructor::proj(const Point& p) const {
+  return (*projector_)(p);
+}
+
+void Viewer_instructor::sceneChanged() {
+  UIDBG("sceneChanged");
+  viewer_->update_GL();
+}
+
+void Viewer_instructor::change_draw_vertices() {
+  view_params_.change_vertex_mode();
+}
+
+void Viewer_instructor::change_draw_edges() {
+  view_params_.change_edge_mode();
+}
+
+void Viewer_instructor::change_draw_triangles() {
+  view_params_.change_triangle_mode();
+}
+
+void Viewer_instructor::change_light() {
+  view_params_.light = !view_params_.light;
+}
+
+#include "Viewer_instructor.moc"
diff --git a/GudhUI/view/Viewer_instructor.h b/GudhUI/view/Viewer_instructor.h
new file mode 100644
index 00000000..1da28009
--- /dev/null
+++ b/GudhUI/view/Viewer_instructor.h
@@ -0,0 +1,117 @@
+/* This file is part of the Gudhi Library. The Gudhi library 
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++ 
+ *    library for computational topology.
+ *
+ *    Author(s):       David Salinas
+ *
+ *    Copyright (C) 2014  INRIA Sophia Antipolis-Mediterranee (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+#ifndef VIEW_VIEWER_INSTRUCTOR_H_
+#define VIEW_VIEWER_INSTRUCTOR_H_
+
+// todo do a viewer instructor that have directely a pointer to a QGLviewer and buffer ot not triangles
+
+// Workaround for moc-qt4 not parsing boost headers
+#include <CGAL/config.h>
+
+#include <QFileDialog>
+#include <QKeyEvent>
+#include <QGLViewer/camera.h>
+
+#include <memory>
+#include <utility>  // for pair<>
+
+#include "model/Complex_typedefs.h"
+
+#include "Projector3D.h"
+#include "View_parameter.h"
+#include "Viewer.h"
+
+class Viewer;
+class Viewer_parameter;
+
+class Viewer_instructor : public QWidget {
+  Q_OBJECT
+
+  typedef Geometry_trait::Point_3 Point_3;
+  typedef Complex::Point Point;
+  typedef Complex::Vertex_handle Vertex_handle;
+  typedef Complex::Edge_handle Edge_handle;
+  typedef Complex::Simplex Simplex;
+
+  Viewer* viewer_;
+  View_parameter view_params_;
+  const Complex& mesh_;
+  std::unique_ptr<Projector3D> projector_;
+
+ public:
+  Viewer_instructor(QWidget* parent, Viewer* viewer, const Complex& mesh);
+
+  void initialize_bounding_box();
+
+  std::pair<Point, Point> compute_bounding_box_corners();
+
+  void show_entire_scene();
+
+  const qglviewer::Camera* camera() const;
+
+  int width() const;
+  int height() const;
+
+  /**
+   * to change display parameters
+   */
+  View_parameter& view_params();
+
+ public:
+  /**
+   * gives instructions to the viewer
+   */
+  void give_instructions();
+
+  void draw_edges();
+  void draw_triangles();
+  void draw_points();
+
+  void draw_edge(const Point&, const Point&);
+
+  void draw_point(const Point&);
+
+  /**
+   * set the right color of vertex/edge/triangle considering the view_params choice
+   */
+  void set_color_vertex(Vertex_handle vh);
+  void set_color_edge(Edge_handle eh);
+
+  void set_color_triangle(const Simplex& triangle);
+
+ private:
+  /**
+   * Projection to 3D needed for the viewer.
+   */
+  Point_3 proj(const Point& p) const;
+
+ public slots:
+  void sceneChanged();
+  void change_draw_vertices();
+  void change_draw_edges();
+  void change_draw_triangles();
+  void change_light();
+};
+
+#endif  // VIEW_VIEWER_INSTRUCTOR_H_