Re: [Numpy-discussion] ndarray.count() ?

2006-09-07 Thread Martin Spacek
Great! That's exactly what I wanted. Works with floats too. Thanks, Martin Robert Kern wrote: > Mostly, it's simply easy enough to implement yourself. Not all one-liners > should > be methods on the array object. > >(a == value).sum() > -

[Numpy-discussion] ndarray.count() ?

2006-09-07 Thread Martin Spacek
What's the most straightforward way to count, say, the number of 1s or Trues in the array? Or the number of any integer? I was surprised to discover recently that there isn't a count() method as there is for Python lists. Sorry if this has been discussed already, but I'm wondering if there's a

Re: [Numpy-discussion] Numpy that is compatible with Scipy windows installer version

2006-09-06 Thread Martin Spacek
Ryan, Try installing the latest scipy version 0.51. There's a windows binary for it. Worked fine for me. Martin Ryan Krauss wrote: > I am a Linux user trying to install Numpy/Scipy on a Windows machine > in my office. > > I went to the website and grabbed the two latest versions: > scipy = sci

Re: [Numpy-discussion] Keyword added to searchsorted.

2006-09-05 Thread Martin Spacek
I agree. This'll allow me to delete some messy code I have to get the same behaviour. I'm amazed by how often I use searchsorted. 'side' sounds like a good keyword name to me. Martin Robert Kern wrote: > Charles R Harris wrote: >> Hi all, >> >> I added the keyword side to the searchsorted meth

Re: [Numpy-discussion] Optimizing mean(axis=0) on a 3D array

2006-08-28 Thread Martin Spacek
Martin Spacek wrote: > > Actually, your original version is just as fast as the take() version. > Both are about 9X faster than numpy.mean() on my system. I prefer the > take() version because you only have to pass a single argument to > mean_accum() I forgot to mention that

Re: [Numpy-discussion] Optimizing mean(axis=0) on a 3D array

2006-08-28 Thread Martin Spacek
Tim Hochberg wrote: > I'm actually surprised that the take version is faster than my original > version since it makes a big ol' copy. I guess this is an indication > that indexing is more expensive than I realize. That's why nothing beats > measuring! Actually, your original version is just

Re: [Numpy-discussion] Optimizing mean(axis=0) on a 3D array

2006-08-27 Thread Martin Spacek
Tim Hochberg wrote: > Here's an approach (mean_accumulate) that avoids making any copies of > the data. It runs almost 4x as fast as your approach (called baseline > here) on my box. Perhaps this will be useful: > --snip-- > def mean_accumulate(data, indices): > result = np.zeros([32, 32],

Re: [Numpy-discussion] Optimizing mean(axis=0) on a 3D array

2006-08-27 Thread Martin Spacek
Travis Oliphant wrote: > > If frameis is 1-D, then you should be able to use > > temp = data.take(frameis,axis=0) > > for the first step. This can be quite a bit faster (and is a big > reason why take is still around). There are several reasons for this > (one of which is that index check

[Numpy-discussion] Optimizing mean(axis=0) on a 3D array

2006-08-26 Thread Martin Spacek
Hello, I'm a bit ignorant of optimization in numpy. I have a movie with 65535 32x32 frames stored in a 3D array of uint8 with shape (65535, 32, 32). I load it from an open file f like this: >>> import numpy as np >>> data = np.fromfile(f, np.uint8, count=65535*32*32) >>> data = data.reshape(