Need help vectorizing code

Newsgroups	comp.lang.python
Date	2014-01-18 12:51 -0800
Message-ID	<140f8aea-d3c5-4c0d-94f5-6aa064e353d1@googlegroups.com> (permalink)
Subject	Need help vectorizing code
From	Kevin K <richyokevin@gmail.com>

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I have some code that I need help vectorizing.
I want to convert the following to vector form, how can I? I want to get rid of the inner loop - apparently, it's possible to do so.
X is an NxD matrix. y is a 1xD vector.

def foo(X, y, mylambda, N, D, epsilon):
...
        for j in xrange(D):
            aj = 0
            cj = 0
            for i in xrange(N):
                aj += 2 * (X[i,j] ** 2)
                cj += 2 * (X[i,j] * (y[i] - w.transpose()*X[i].transpose() + w[j]*X[i,j]))

...

If I call numpy.vectorize() on the function, it throws an error at runtime.

Thanks

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Thread

Need help vectorizing code Kevin K <richyokevin@gmail.com> - 2014-01-18 12:51 -0800
  Re: Need help vectorizing code Joshua Landau <joshua@landau.ws> - 2014-01-18 21:04 +0000
  Re: Need help vectorizing code Kevin K <richyokevin@gmail.com> - 2014-01-18 13:18 -0800
  Re: Need help vectorizing code Peter Otten <__peter__@web.de> - 2014-01-18 22:50 +0100
  Re: Need help vectorizing code Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2014-01-19 15:46 +0000

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