1 files changed, 87 insertions, 0 deletions
diff --git a/src/python/gudhi/reader_utils.pyx b/src/python/gudhi/reader_utils.pyx
new file mode 100644
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+++ b/src/python/gudhi/reader_utils.pyx
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+from cython cimport numeric
+from libcpp.vector cimport vector
+from libcpp.string cimport string
+from libcpp.map cimport map
+from libcpp.pair cimport pair
+
+from os import path
+from numpy import array as np_array
+
+""" This file is part of the Gudhi Library - https://gudhi.inria.fr/ - which is released under MIT.
+    See file LICENSE or go to https://gudhi.inria.fr/licensing/ for full license details.
+    Author(s):       Vincent Rouvreau
+
+    Copyright (C) 2017 Inria
+
+    Modification(s):
+      - YYYY/MM Author: Description of the modification
+"""
+
+__author__ = "Vincent Rouvreau"
+__copyright__ = "Copyright (C) 2017 Inria"
+__license__ = "MIT"
+
+cdef extern from "Reader_utils_interface.h" namespace "Gudhi":
+    vector[vector[double]] read_matrix_from_csv_file(string off_file, char separator)
+    map[int, vector[pair[double, double]]] read_pers_intervals_grouped_by_dimension(string filename)
+    vector[pair[double, double]] read_pers_intervals_in_dimension(string filename, int only_this_dim)
+
+def read_lower_triangular_matrix_from_csv_file(csv_file='', separator=';'):
+    """Read lower triangular matrix from a CSV style file.
+
+    :param csv_file: A CSV file style name.
+    :type csv_file: string
+    :param separator: The value separator in the CSV file. Default value is ';'
+    :type separator: char
+
+    :returns:  The lower triangular matrix.
+    :rtype: vector[vector[double]]
+    """
+    if csv_file is not '':
+        if path.isfile(csv_file):
+            return read_matrix_from_csv_file(str.encode(csv_file), ord(separator[0]))
+    print("file " + csv_file + " not set or not found.")
+    return []
+
+def read_persistence_intervals_grouped_by_dimension(persistence_file=''):
+    """Reads a file containing persistence intervals.
+    Each line might contain 2, 3 or 4 values: [[field] dimension] birth death
+    The return value is an `map[dim, vector[pair[birth, death]]]`
+    where `dim` is an `int`, `birth` a `double`, and `death` a `double`.
+    Note: the function does not check that birth <= death.
+
+    :param persistence_file: A persistence file style name.
+    :type persistence_file: string
+
+    :returns:  The persistence pairs grouped by dimension.
+    :rtype: map[int, vector[pair[double, double]]]
+    """
+    if persistence_file is not '':
+        if path.isfile(persistence_file):
+            return read_pers_intervals_grouped_by_dimension(str.encode(persistence_file))
+    print("file " + persistence_file + " not set or not found.")
+    return []
+
+def read_persistence_intervals_in_dimension(persistence_file='', only_this_dim=-1):
+    """Reads a file containing persistence intervals.
+    Each line of persistence_file might contain 2, 3 or 4 values:
+    [[field] dimension] birth death
+    Note: the function does not check that birth <= death.
+
+    :param persistence_file: A persistence file style name.
+    :type persistence_file: string
+    :param only_this_dim: The specific dimension. Default value is -1.
+        If `only_this_dim` = -1, dimension is ignored and all lines are returned.
+        If `only_this_dim` is >= 0, only the lines where dimension =
+        `only_this_dim` (or where dimension is not specified) are returned.
+    :type only_this_dim: int.
+
+    :returns:  The persistence intervals.
+    :rtype: numpy array of dimension 2
+    """
+    if persistence_file is not '':
+        if path.isfile(persistence_file):
+            return np_array(read_pers_intervals_in_dimension(str.encode(
+                persistence_file), only_this_dim))
+    print("file " + persistence_file + " not set or not found.")
+    return []