[Numpy-discussion] Selecting columns of a matrix

Alan G Isaac aisaac at american.edu
Wed Jun 21 03:48:15 CDT 2006


On Tue, 20 Jun 2006, Keith Goodman apparently wrote: 
> I have a matrix M and a vector (n by 1 matrix) V. I want to form a new 
> matrix that contains the columns of M for which V > 0. 
> One way to do that in Octave is M(:, find(V > 0)). How is it done in numpy? 

M.transpose()[V>0]
If you want the columns as columns,
you can transpose again.

hth,
Alan Isaac







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