From 81a29b51428e902e89ce878cbcefb74239203414 Mon Sep 17 00:00:00 2001 From: vrouvrea Date: Tue, 20 Mar 2018 15:27:09 +0000 Subject: Finish the documentation and examples git-svn-id: svn+ssh://scm.gforge.inria.fr/svnroot/gudhi/branches/python_nerve_gic_vincent@3299 636b058d-ea47-450e-bf9e-a15bfbe3eedb Former-commit-id: d60f4db274962c1c6aaef3c4ab6787bda8c0640f --- src/cython/doc/examples.rst | 4 ++ src/cython/doc/nerve_gic_complex_user.rst | 90 +++++++++++++++++++++++++++++++ 2 files changed, 94 insertions(+) (limited to 'src/cython/doc') diff --git a/src/cython/doc/examples.rst b/src/cython/doc/examples.rst index 1e596e18..58b25793 100644 --- a/src/cython/doc/examples.rst +++ b/src/cython/doc/examples.rst @@ -19,3 +19,7 @@ Examples * :download:`rips_complex_diagram_persistence_from_distance_matrix_file_example.py <../example/rips_complex_diagram_persistence_from_distance_matrix_file_example.py>` * :download:`rips_persistence_diagram.py <../example/rips_persistence_diagram.py>` * :download:`random_cubical_complex_persistence_example.py <../example/random_cubical_complex_persistence_example.py>` + * :download:`coordinate_graph_induced_complex.py <../example/coordinate_graph_induced_complex.py>` + * :download:`functional_graph_induced_complex.py <../example/functional_graph_induced_complex.py>` + * :download:`voronoi_graph_induced_complex.py <../example/voronoi_graph_induced_complex.py>` + * :download:`nerve_of_a_covering.py <../example/nerve_of_a_covering.py>` diff --git a/src/cython/doc/nerve_gic_complex_user.rst b/src/cython/doc/nerve_gic_complex_user.rst index 7edf0578..b2669303 100644 --- a/src/cython/doc/nerve_gic_complex_user.rst +++ b/src/cython/doc/nerve_gic_complex_user.rst @@ -220,3 +220,93 @@ one can obtain the following visualization: :alt: Visualization with Geomview Visualization with Geomview + +Functional GIC +^^^^^^^^^^^^^^ + +If one restricts to the cliques in G whose nodes all belong to preimages of +consecutive intervals (assuming the cover of the height function is minimal, +i.e. no more than two intervals can intersect at a time), the GIC is of +dimension one, i.e. a graph. +We call this graph the functional GIC. See :cite:`Carriere16` for more details. + +Example +^^^^^^^ + +Functional GIC comes with automatic selection of the Rips threshold, +the resolution and the gain of the function cover. See :cite:`Carriere17c` for +more details. In this example, we compute the functional GIC of a Klein bottle +embedded in R^5, where the graph G comes from a Rips complex with automatic +threshold, and the cover C comes from the preimages of intervals covering the +first coordinate, with automatic resolution and gain. Note that automatic +threshold, resolution and gain can be computed as well for the Nerve. + +.. testcode:: + + import gudhi + nerve_complex = gudhi.CoverComplex() + + if (nerve_complex.read_point_cloud(gudhi.__root_source_dir__ + \ + '/data/points/KleinBottle5D.off')): + nerve_complex.set_type('GIC') + nerve_complex.set_color_from_coordinate(0) + nerve_complex.set_function_from_coordinate(0) + nerve_complex.set_graph_from_automatic_rips() + nerve_complex.set_automatic_resolution() + nerve_complex.set_gain() + nerve_complex.set_cover_from_function() + nerve_complex.find_simplices() + nerve_complex.plot_dot() + +the program outputs SC.dot. Using e.g. + +.. code-block:: none + + neato ../../data/points/KleinBottle5D.off_sc.dot -Tpdf -o ../../data/points/KleinBottle5D.off_sc.pdf + +one can obtain the following visualization: + +.. figure:: + ../../doc/Nerve_GIC/coordGICvisu2.jpg + :figclass: align-center + :alt: Visualization with neato + + Visualization with neato + +where nodes are colored by the filter function values and, for each node, the +first number is its ID and the second is the number of data points that its +contain. + +We also provide an example on a set of 72 pictures taken around the same object +(lucky_cat.off). +The function is now the first eigenfunction given by PCA, whose values are +written in a file (lucky_cat_PCA1). Threshold, resolution and gain are +automatically selected as before. + +.. testcode:: + + import gudhi + nerve_complex = gudhi.CoverComplex() + + if (nerve_complex.read_point_cloud(gudhi.__root_source_dir__ + \ + '/data/points/COIL_database/lucky_cat.off')): + nerve_complex.set_type('GIC') + pca_file = gudhi.__root_source_dir__ + \ + '/data/points/COIL_database/lucky_cat_PCA1' + nerve_complex.set_color_from_file(pca_file) + nerve_complex.set_function_from_file(pca_file) + nerve_complex.set_graph_from_automatic_rips() + nerve_complex.set_automatic_resolution() + nerve_complex.set_gain() + nerve_complex.set_cover_from_function() + nerve_complex.find_simplices() + nerve_complex.plot_dot() + +the program outputs again SC.dot which gives the following visualization after using neato: + +.. figure:: + ../../doc/Nerve_GIC/funcGICvisu.jpg + :figclass: align-center + :alt: Visualization with neato + + Visualization with neato -- cgit v1.2.3