dask.array.roll
dask.array.roll¶
- dask.array.roll(array, shift, axis=None)[source]¶
Roll array elements along a given axis.
This docstring was copied from numpy.roll.
Some inconsistencies with the Dask version may exist.
Elements that roll beyond the last position are re-introduced at the first.
- Parameters
- aarray_like (Not supported in Dask)
Input array.
- shiftint 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.
- axisint or tuple of ints, optional
Axis or axes along which elements are shifted. By default, the array is flattened before shifting, after which the original shape is restored.
- Returns
- resndarray
Output array, with the same shape as a.
See also
rollaxis
Roll the specified axis backwards, until it lies in a given position.
Notes
New in version 1.12.0.
Supports rolling over multiple dimensions simultaneously.
Examples
>>> x = np.arange(10) >>> np.roll(x, 2) array([8, 9, 0, 1, 2, 3, 4, 5, 6, 7]) >>> np.roll(x, -2) array([2, 3, 4, 5, 6, 7, 8, 9, 0, 1])
>>> x2 = np.reshape(x, (2,5)) >>> x2 array([[0, 1, 2, 3, 4], [5, 6, 7, 8, 9]]) >>> np.roll(x2, 1) array([[9, 0, 1, 2, 3], [4, 5, 6, 7, 8]]) >>> np.roll(x2, -1) array([[1, 2, 3, 4, 5], [6, 7, 8, 9, 0]]) >>> np.roll(x2, 1, axis=0) array([[5, 6, 7, 8, 9], [0, 1, 2, 3, 4]]) >>> np.roll(x2, -1, axis=0) array([[5, 6, 7, 8, 9], [0, 1, 2, 3, 4]]) >>> np.roll(x2, 1, axis=1) array([[4, 0, 1, 2, 3], [9, 5, 6, 7, 8]]) >>> np.roll(x2, -1, axis=1) array([[1, 2, 3, 4, 0], [6, 7, 8, 9, 5]])