numpy.rollaxis¶

numpy.rollaxis(a,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 youshould prefermoveaxis. Themoveaxis function was added in NumPy1.11.

Parameters:	a:ndarray Input array. axis:int The axis to roll backwards. The positions of the other axes do notchange relative to one another. start:int, optional The axis is rolled until it lies before this position. The default,0, results in a “complete” roll.
Returns:	res:ndarray For NumPy >= 1.10.0 a view ofa is always returned. For earlierNumPy versions a view ofa is returned only if the order of theaxes is changed, otherwise the input array is returned.

See also

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)