NumPy: rollaxis() function

numpy.rollaxis() function

The rollaxis() function is used to 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.

Syntax:

numpy.rollaxis(a, source, destination)

Version: 1.15.0

Parameter:

Return value:

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.

Example-1: numpy.rollaxis() function

>>> import numpy as np
>>> a = np.ones((2,3, 4, 5))
>>> np.rollaxis(a, 2, 1).shape
(2, 4, 3, 5)

Pictorial Presentation:

Example-2: numpy.rollaxis() function

>>> import numpy as np
>>> y = np.ones((2,3, 4, 5))
>>> np.rollaxis(y, 2, 1).shape
(2, 4, 3, 5)

Pictorial Presentation:

Example-3: numpy.rollaxis() function

>>> import numpy as np
>>> y = np.ones((2,3, 4, 5))
>>> np.rollaxis(y, 3).shape
(5, 2, 3, 4)

Pictorial Presentation:

Example-4: numpy.rollaxis() function

>>> import numpy as np
>>> y = np.ones((2,3, 4, 5))
>>> np.rollaxis(y, 1, 3).shape
(2, 4, 3, 5)

Pictorial Presentation:

Python - NumPy Code Editor:

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