[Numpy-discussion] A matrix user in the land of arrays

Keith Goodman kwgoodman@gmail....
Fri May 9 12:52:08 CDT 2008

The recently proposed changes to the matrix class was the final push I
needed to begin slowly porting my package from matrices to arrays. But
I'm already stuck in the first stage (all new modules must use

Here's a toy example of iterating over columns of a matrix:

x is a nxm matrix
y is a nx1 matrix

for j in xrange(x.shape[1]):
    idx = where(y > scalar)[0]
    x[idx,j] = scalar

If x and y become 2d arrays, the code still works. But what confuses
me is how to generalize it to work for both 2d and 1d arrays.

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