Roll the specified axis backwards, until it lies in a given position.
This function continues to be supported for backward compatibility, but you
should prefer moveaxis. The moveaxis function was added in NumPy
The axis to be rolled. The positions of the other axes do not
change relative to one another.
When start <= axis, the axis is rolled back until it lies in
this position. When start > axis, the axis is rolled until it
lies before this position. The default, 0, results in a “complete”
roll. The following table describes how negative values of start
start <= axis
start > axis
arr.ndim + 1
For NumPy >= 1.10.0 a view of a is always returned. For earlier
NumPy versions a view of a is returned only if the order of the
axes is changed, otherwise the input array is returned.
Move array axes to new positions.
Roll the elements of an array by a number of positions along a given axis.
>>> a = np.ones((3,4,5,6))
>>> np.rollaxis(a, 3, 1).shape
(3, 6, 4, 5)
>>> np.rollaxis(a, 2).shape
(5, 3, 4, 6)
>>> np.rollaxis(a, 1, 4).shape
(3, 5, 6, 4)