Numpy: Assignment and Indexing as Matlab

Question

Sometimes is useful to assign arrays with one index only. In Matlab this is straightforward:

M = zeros(4);
M(1:5:end) = 1
M =

   1   0   0   0
   0   1   0          


        

Answer 1

Another way using unravel_index

>>> M = zeros((4,4));
>>> M[unravel_index(arange(0,4*4,5),(4,4))]= 1
>>> M
array([[ 1.,  0.,  0.,  0.],
       [ 0.,  1.,  0.,  0.],
       [ 0.,  0.,  1.,  0.],
       [ 0.,  0.,  0.,  1.]])