# xorbits.numpy.rollaxis#

xorbits.numpy.rollaxis(tensor, axis, start=0)[source]#

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 1.11.

Parameters
• a (ndarray (Not supported yet)) – Input array.

• axis (int) – The axis to be rolled. The positions of the other axes do not change relative to one another.

• start (int, optional) –

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` are interpreted:

`start`

Normalized `start`

`-(arr.ndim+1)`

raise `AxisError`

`-arr.ndim`

0

`-1`

`arr.ndim-1`

`0`

`0`

`arr.ndim`

`arr.ndim`

`arr.ndim + 1`

raise `AxisError`

Returns

res – 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.

Return type

ndarray

`moveaxis`

Move array axes to new positions.

`roll`

Roll the elements of an array by a number of positions along a given axis.

Examples

```>>> 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)
```

This docstring was copied from numpy.