[Numpy-discussion] Memory leak with matrices?

2010-03-09 Thread David Paul Reichert
Hi, I've got two issues: First, the following seems to cause a memory leak, using numpy 1.3.0: a = matrix(ones(1)) while True: a += 0 This only seems to happen when a is a matrix rather than an array, and when the short hand '+=' is used. Second, I'm not sure whether that's a bug or whet

[Numpy-discussion] Adding zero-dimension arrays, bug?

2009-06-09 Thread David Paul Reichert
Hi, Numpy let's me define arrays with zero rows and/or columns, and that's wanted behaviour from what I have read in discussions. However, I can add an array with zero rows to an array with one row (but not more), resulting in another zero row array, like so: In: a = zeros((4,0)) In: a Out: arr

Re: [Numpy-discussion] performance matrix multiplication vs. matlab

2009-06-05 Thread David Paul Reichert
st suggests that the latest version of Ubuntu is up-to-date wrt > ATLAS: > > http://www.mail-archive.com/numpy-discussion@scipy.org/msg13102.html > > Jason > > On Fri, Jun 5, 2009 at 5:44 AM, David Paul Reichert < > d.p.reich...@sms.ed.ac.uk> wrote: > >> Thanks

Re: [Numpy-discussion] performance matrix multiplication vs. matlab

2009-06-05 Thread David Paul Reichert
Thanks for the replies so far. I had already tested using an already transposed matrix in the loop, it didn't make any difference. Oh and btw, I'm on (Scientific) Linux. I used the Enthought distribution, but I guess I'll have to get my hands dirty and try to get that Atlas thing working (I'm not

[Numpy-discussion] performance matrix multiplication vs. matlab

2009-06-04 Thread David Paul Reichert
Hi all, I would be glad if someone could help me with the following issue: From what I've read on the web it appears to me that numpy should be about as fast as matlab. However, when I do simple matrix multiplication, it consistently appears to be about 5 times slower. I tested this using A = 0