flopscope.

flopscope.numpy.rollaxis

fnp.rollaxis(a, axis, start=0)[flopscope source][numpy source]

Roll the specified axis backwards, until it lies in a given position.

Adapted from NumPy docs np.rollaxis

Areacore
Typefree
NumPy Refnp.rollaxis
Cost
0
Flopscope Context

Roll specified axis backwards. Cost: numel(output).

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

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:

table .
substitution_definition
⋮

Returns

res:ndarray

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.

See also

Examples

>>> import flopscope.numpy as fnp
>>> a = flops.ones((3,4,5,6))
>>> flops.rollaxis(a, 3, 1).shape
(3, 6, 4, 5)
>>> flops.rollaxis(a, 2).shape
(5, 3, 4, 6)
>>> flops.rollaxis(a, 1, 4).shape
(3, 5, 6, 4)