Re: [Numpy-discussion] efficient use of numpy.where() and .any()

On 23/04/07, Pierre GM <pgmdevlist@gmail.com> wrote:

Note that in addition of the bitwise operators, you can use the "logical_" functions. OK, you'll still end up w/ temporaries, but I wonder whether there couldn't be some tricks to bypass that...

If you're really determined not to make many temps, you can use their output arguments and do it all in-place on the first temporary. The few times I've rewritten code that way it hasn't made an appreciable positive difference in the speed, and it was sometimes significantly slower, perhaps because of the increased memory footprint (the temps were longer-lived than when I did it by hand). malloc() is really really cheap, and garbage collection is also extremely cheap for huge arrays. Anne