numpy.diag_indices_from#
- numpy.diag_indices_from(arr)[source]#
Return the indices to access the main diagonal of an n-dimensional array.
See
diag_indices
for full details.- Parameters:
- arrarray, at least 2-D
See also
Notes
New in version 1.4.0.
Examples
Create a 4 by 4 array.
>>> a = np.arange(16).reshape(4, 4) >>> a array([[ 0, 1, 2, 3], [ 4, 5, 6, 7], [ 8, 9, 10, 11], [12, 13, 14, 15]])
Get the indices of the diagonal elements.
>>> di = np.diag_indices_from(a) >>> di (array([0, 1, 2, 3]), array([0, 1, 2, 3]))
>>> a[di] array([ 0, 5, 10, 15])
This is simply syntactic sugar for diag_indices.
>>> np.diag_indices(a.shape[0]) (array([0, 1, 2, 3]), array([0, 1, 2, 3]))