Re: [Numpy-discussion] multiprocessing shared arrays and numpy

2010-03-05 Thread Francesc Alted
Yeah, 10% of improvement by using multi-cores is an expected figure for memory bound problems. This is something people must know: if their computations are memory bound (and this is much more common that one may initially think), then they should not expect significant speed-ups on their

[Numpy-discussion] Is this a bug in numpy.ma.reduce?

2010-03-05 Thread David Goldsmith
Hi! Sorry for the cross-post, but my own investigation has led me to suspect that mine is actually a numpy problem, not a matplotlib problem. I'm getting the following traceback from a call to matplotlib.imshow: Traceback (most recent call last): File

Re: [Numpy-discussion] multiprocessing shared arrays and numpy

2010-03-05 Thread Gael Varoquaux
On Fri, Mar 05, 2010 at 09:53:02AM +0100, Francesc Alted wrote: Yeah, 10% of improvement by using multi-cores is an expected figure for memory bound problems. This is something people must know: if their computations are memory bound (and this is much more common that one may initially

Re: [Numpy-discussion] Is this a bug in numpy.ma.reduce?

2010-03-05 Thread Pierre GM
On Mar 5, 2010, at 4:38 AM, David Goldsmith wrote: Hi! Sorry for the cross-post, but my own investigation has led me to suspect that mine is actually a numpy problem, not a matplotlib problem. I'm getting the following traceback from a call to matplotlib.imshow: ... Based on examination

Re: [Numpy-discussion] Is this a bug in numpy.ma.reduce?

2010-03-05 Thread Vincent Schut
On 03/05/2010 11:51 AM, Pierre GM wrote: On Mar 5, 2010, at 4:38 AM, David Goldsmith wrote: Hi! Sorry for the cross-post, but my own investigation has led me to suspect that mine is actually a numpy problem, not a matplotlib problem. I'm getting the following traceback from a call to

Re: [Numpy-discussion] multiprocessing shared arrays and numpy

2010-03-05 Thread Francesc Alted
Gael, On Fri, Mar 05, 2010 at 10:51:12AM +0100, Gael Varoquaux wrote: On Fri, Mar 05, 2010 at 09:53:02AM +0100, Francesc Alted wrote: Yeah, 10% of improvement by using multi-cores is an expected figure for memory bound problems. This is something people must know: if their computations

Re: [Numpy-discussion] multiprocessing shared arrays and numpy

2010-03-05 Thread Gael Varoquaux
On Fri, Mar 05, 2010 at 08:14:51AM -0500, Francesc Alted wrote: FWIW, I observe very good speedups on my problems (pretty much linear in the number of CPUs), and I have data parallel problems on fairly large data (~100Mo a piece, doesn't fit in cache), with no synchronisation at all

[Numpy-discussion] printing structured arrays

2010-03-05 Thread Bruce Schultz
Hi, I've just started playing with numpy and have noticed that when printing a structured array that the output is not nicely formatted. Is there a way to make the formatting look the same as it does for an unstructured array? Here an example of what I mean: data = [ (1, 2), (3, 4.1) ] dtype =

Re: [Numpy-discussion] Why does np.nan{min, max} clobber my array mask?

2010-03-05 Thread Bruce Southey
On Mon, Feb 15, 2010 at 9:24 PM, Bruce Southey bsout...@gmail.com wrote: On Mon, Feb 15, 2010 at 8:35 PM, Pierre GM pgmdevl...@gmail.com wrote: On Feb 15, 2010, at 8:51 PM, David Carmean wrote: On Sun, Feb 14, 2010 at 03:22:04PM -0500, Pierre GM wrote: I'm sorry, I can't follow you. Can you

Re: [Numpy-discussion] multiprocessing shared arrays and numpy

2010-03-05 Thread Francesc Alted
A Friday 05 March 2010 14:46:00 Gael Varoquaux escrigué: On Fri, Mar 05, 2010 at 08:14:51AM -0500, Francesc Alted wrote: FWIW, I observe very good speedups on my problems (pretty much linear in the number of CPUs), and I have data parallel problems on fairly large data (~100Mo a piece,

[Numpy-discussion] Loading bit strings

2010-03-05 Thread Dan Lenski
Is there a good way in NumPy to convert from a bit string to a boolean array? For example, if I have a 2-byte string s='\xfd\x32', I want to get a 16-length boolean array out of it. Here's what I came up with: A = fromstring(s, dtype=uint8) out = empty(A.size * 8, dtype=bool) for bit in

Re: [Numpy-discussion] Is this a bug in numpy.ma.reduce?

2010-03-05 Thread David Goldsmith
On Fri, Mar 5, 2010 at 2:51 AM, Pierre GM pgmdevl...@gmail.com wrote: On Mar 5, 2010, at 4:38 AM, David Goldsmith wrote: Hi! Sorry for the cross-post, but my own investigation has led me to suspect that mine is actually a numpy problem, not a matplotlib problem. I'm getting the following

Re: [Numpy-discussion] Loading bit strings

2010-03-05 Thread Robert Kern
On Fri, Mar 5, 2010 at 11:11, Dan Lenski dlen...@gmail.com wrote: Is there a good way in NumPy to convert from a bit string to a boolean array? For example, if I have a 2-byte string s='\xfd\x32', I want to get a 16-length boolean array out of it. Here's what I came up with: A =

Re: [Numpy-discussion] Is this a bug in numpy.ma.reduce?

2010-03-05 Thread David Goldsmith
On Fri, Mar 5, 2010 at 9:22 AM, David Goldsmith d.l.goldsm...@gmail.comwrote: On Fri, Mar 5, 2010 at 2:51 AM, Pierre GM pgmdevl...@gmail.com wrote: On Mar 5, 2010, at 4:38 AM, David Goldsmith wrote: Hi! Sorry for the cross-post, but my own investigation has led me to suspect that mine is

Re: [Numpy-discussion] Is this a bug in numpy.ma.reduce?

2010-03-05 Thread David Goldsmith
On Fri, Mar 5, 2010 at 9:43 AM, David Goldsmith d.l.goldsm...@gmail.comwrote: On Fri, Mar 5, 2010 at 9:22 AM, David Goldsmith d.l.goldsm...@gmail.comwrote: On Fri, Mar 5, 2010 at 2:51 AM, Pierre GM pgmdevl...@gmail.com wrote: On Mar 5, 2010, at 4:38 AM, David Goldsmith wrote: Hi! Sorry

Re: [Numpy-discussion] Loading bit strings

2010-03-05 Thread Zachary Pincus
Is there a good way in NumPy to convert from a bit string to a boolean array? For example, if I have a 2-byte string s='\xfd\x32', I want to get a 16-length boolean array out of it. numpy.unpackbits(numpy.fromstring('\xfd\x32', dtype=numpy.uint8))

Re: [Numpy-discussion] multiprocessing shared arrays and numpy

2010-03-05 Thread Brian Granger
Francesc, Yeah, 10% of improvement by using multi-cores is an expected figure for memory bound problems. This is something people must know: if their computations are memory bound (and this is much more common that one may initially think), then they should not expect significant speed-ups

Re: [Numpy-discussion] Iterative Matrix Multiplication

2010-03-05 Thread Friedrich Romstedt
Do you have doublets in the v_array? In case not, then you owe me a donut. See attachment. Friedrich P.S.: You misunderstood too, the line you wanted to change was in context to detect back-facing triangles, and there one vertex is sufficient. shading.py Description: Binary data

Re: [Numpy-discussion] printing structured arrays

2010-03-05 Thread Gökhan Sever
On Fri, Mar 5, 2010 at 8:00 AM, Bruce Schultz bruce.schu...@gmail.comwrote: Hi, I've just started playing with numpy and have noticed that when printing a structured array that the output is not nicely formatted. Is there a way to make the formatting look the same as it does for an

Re: [Numpy-discussion] Iterative Matrix Multiplication

2010-03-05 Thread Ian Mallett
Cool--this works perfectly now :-) Unfortunately, it's actually slower :P Most of the slowest part is in the removing doubles section. Some of the costliest calls: #takes 0.04 seconds inner = np.inner(ns, v1s - some_point) #0.0840001106262 sum_1 = sum.reshape((len(sum), 1)).repeat(len(sum),

Re: [Numpy-discussion] Building Numpy Windows Superpack

2010-03-05 Thread David Cournapeau
On Fri, Mar 5, 2010 at 1:22 PM, Patrick Marsh patrickmars...@gmail.com wrote: I've run the Numpy superpack installer for Python 2.6 built with MinGW through the dependency walker.  Unfortunately, outside of checking for some extremely obviously things, I'm in way over my head in interpreting