fix #631 : implemented LArray.reverse() method

Author: alixdamman

doc/source/api.rst

@@ -329,6 +329,7 @@ Changing Axes or Labels
    LArray.set_labels
    LArray.combine_axes
    LArray.split_axes
+   LArray.reverse
 
 .. _la_agg:
 

doc/source/changes/version_0_30.rst.inc

@@ -221,6 +221,8 @@ Miscellaneous improvements
 * renamed `a_min` and `a_max` arguments of :py:obj:`LArray.clip()` as `minval` and `maxval` respectively
   and made them optional (closes :issue:`747`).
 
+* implemented :py:obj:`LArray.reverse()` method to reverse one or several axes of an array (closes :issue:`631`).
+
 
 Fixes
 -----

larray/core/array.py

@@ -7144,6 +7144,66 @@ def split_axes(self, axes=None, sep='_', names=None, regex=None, sort=False, fil
         return array
     split_axis = renamed_to(split_axes, 'split_axis')
 
+    def reverse(self, axes=None):
+        r"""
+        Reverse axes of an array
+
+        Parameters
+        ----------
+        axes : int, str, Axis or any combination of those
+            axes to reverse. If None, all axes are reversed. Defaults to None.
+
+        Returns
+        -------
+        LArray
+            Array with passed `axes` reversed.
+
+        Examples
+        --------
+        >>> arr = ndtest((2, 2, 2))
+        >>> arr
+         a  b\c  c0  c1
+        a0   b0   0   1
+        a0   b1   2   3
+        a1   b0   4   5
+        a1   b1   6   7
+
+        Reverse one axis
+
+        >>> arr.reverse('c')
+         a  b\c  c1  c0
+        a0   b0   1   0
+        a0   b1   3   2
+        a1   b0   5   4
+        a1   b1   7   6
+
+        Reverse several axes
+
+        >>> arr.reverse(('a', 'c'))
+         a  b\c  c1  c0
+        a1   b0   5   4
+        a1   b1   7   6
+        a0   b0   1   0
+        a0   b1   3   2
+
+        Reverse all axes
+
+        >>> arr.reverse()
+         a  b\c  c1  c0
+        a1   b1   7   6
+        a1   b0   5   4
+        a0   b1   3   2
+        a0   b0   1   0
+        """
+        if axes is None:
+            axes = self.axes
+        else:
+            axes = self.axes[axes]
+        if not isinstance(axes, AxisCollection):
+            axes = AxisCollection(axes)
+        reversed_axes = tuple(axis[::-1] for axis in axes)
+        return self[reversed_axes]
+
 
 def larray_equal(a1, a2):
     import warnings