Merge branch 'issue_137'

Conflicts:
	doc/whats_new.rst

Author: Guillaume Lemaitre

doc/whats_new.rst

@@ -19,6 +19,7 @@ Bug fixes
 - Fixed a bug in :class:`ensemble.EasyEnsemble`, correction of the `random_state` generation. By `Guillaume Lemaitre`_ and `Christos Aridas`_.
 - Fixed a bug in :class:`under_sampling.RepeatedEditedNearestNeighbours`, add additional stopping criterion to avoid that the minority class become a majority class or that a class disappear. By `Guillaume Lemaitre`_.
 - Fixed a bug in :class:`under_sampling.AllKNN`, add stopping criteria to avoid that the minority class become a majority class or that a class disappear. By `Guillaume Lemaitre`_.
+- Fixed a bug in :class:`under_sampling.CondensedNeareastNeigbour`, correction of the list of indices returned. By `Guillaume Lemaitre`_.
 
 New features
 ~~~~~~~~~~~~

imblearn/under_sampling/condensed_nearest_neighbour.py

@@ -204,6 +204,12 @@ def _sample(self, X, y):
             sel_x = np.squeeze(S_x[idx_maj_sample, :])
             sel_y = S_y[idx_maj_sample]
 
+            # The indexes found are relative to the current class, we need to
+            # find the absolute value
+            # Build the array with the absolute position
+            abs_pos = np.flatnonzero(y == key)
+            idx_maj_sample = abs_pos[idx_maj_sample]
+
             # If we need to offer support for the indices selected
             if self.return_indices:
                 idx_under = np.concatenate((idx_under, idx_maj_sample), axis=0)