remove zero lines 2-D numpy array

Question

I run a qr factorization in numpy which returns a list of ndarrays, namely Qand R:

>>&         


        

Answer 1

Use np.all with an axis argument:

>>> r[np.all(r == 0, axis=1)]
array([[ 0.,  0.,  0.]])
>>> r[~np.all(r == 0, axis=1)]
array([[-1.41421356, -0.70710678, -0.70710678],
       [ 0.        , -1.22474487, -1.22474487]])