Re: [Numpy-discussion] can this be made faster?

[Greg W. <gre...@gm...>]

On 10/8/06, Daniel Mahler <dm...@gm...> wrote:
>
> >>> a
> array([0, 0])
> >>> b
> array([0, 1, 0, 1, 0])
> >>> c
> array([1, 1, 1, 1, 1])
>


Well for this particular example you could do
a=array([len(b)-sum(b), sum(b)])
Since you are just counting the ones and zeros.

This next one is a little closer for the case when c is not just a bunch of
1's but you still have to know how the highest number in b.
a=array([sum(c[b==0]),  sum(c[b==1]), ... sum(c[b==N]) ] )

So it sort of depends on your ultimate goal.
Greg
-- 
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