rollaxis(a, axis, start=0)¶
Roll the specified axis backwards, until it lies in a given position.
The axis to roll backwards. The positions of the other axes do not change relative to one another.
The axis is rolled until it lies before this position. The default, 0, results in a “complete” roll.
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.
>>> 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)