mars.tensor.roll¶

mars.tensor.
roll
(a, shift, axis=None)[source]¶ Roll tensor elements along a given axis.
Elements that roll beyond the last position are reintroduced at the first.
 Parameters
a (array_like) – Input tensor.
shift (int or tuple of ints) – The number of places by which elements are shifted. If a tuple, then axis must be a tuple of the same size, and each of the given axes is shifted by the corresponding number. If an int while axis is a tuple of ints, then the same value is used for all given axes.
axis (int or tuple of ints, optional) – Axis or axes along which elements are shifted. By default, the tensor is flattened before shifting, after which the original shape is restored.
 Returns
res – Output tensor, with the same shape as a.
 Return type
Tensor
See also
rollaxis
Roll the specified axis backwards, until it lies in a given position.
Notes
Supports rolling over multiple dimensions simultaneously.
Examples
>>> import mars.tensor as mt
>>> x = mt.arange(10) >>> mt.roll(x, 2).execute() array([8, 9, 0, 1, 2, 3, 4, 5, 6, 7])
>>> x2 = mt.reshape(x, (2,5)) >>> x2.execute() array([[0, 1, 2, 3, 4], [5, 6, 7, 8, 9]]) >>> mt.roll(x2, 1).execute() array([[9, 0, 1, 2, 3], [4, 5, 6, 7, 8]]) >>> mt.roll(x2, 1, axis=0).execute() array([[5, 6, 7, 8, 9], [0, 1, 2, 3, 4]]) >>> mt.roll(x2, 1, axis=1).execute() array([[4, 0, 1, 2, 3], [9, 5, 6, 7, 8]])