Re: [Numpy-discussion] fancy view question

2009-02-18 Thread Vincent Schut
Gael Varoquaux wrote: On Tue, Feb 17, 2009 at 10:18:11AM -0600, Robert Kern wrote: On Tue, Feb 17, 2009 at 10:16, Gael Varoquaux gael.varoqu...@normalesup.org wrote: On Tue, Feb 17, 2009 at 09:09:38AM -0600, Robert Kern wrote: np.repeat(np.repeat(x, 2, axis=0), 2, axis=1) stride_tricks are

[Numpy-discussion] inplace dot products

2009-02-18 Thread Olivier Grisel
Hi numpist people, I discovered the ufunc and there ability to compute the results on preallocated arrays: a = arange(10, dtype=float32) b = arange(10, dtype=float32) + 1 c = add(a, b, a) c is a True a array([ 1., 3., 5., 7., 9., 11., 13., 15., 17., 19.], dtype=float32)

Re: [Numpy-discussion] views and object lifetime

2009-02-18 Thread Neal Becker
Matthieu Brucher matthieu.brucher at gmail.com writes: B has a reference to A. Could you be more specific? Where is this reference stored? What C api functions are used? Matthieu 2009/2/18 Neal Becker ndbecker2 at gmail.com: How is it ensured, at the C api level, that when I have an

Re: [Numpy-discussion] views and object lifetime

2009-02-18 Thread Matthieu Brucher
2009/2/18 Neal Becker ndbeck...@gmail.com: Matthieu Brucher matthieu.brucher at gmail.com writes: B has a reference to A. Could you be more specific? Where is this reference stored? What C api functions are used? I don't remember, and I don't have the Numpy book here. But if B is a view

Re: [Numpy-discussion] views and object lifetime

2009-02-18 Thread Gael Varoquaux
On Wed, Feb 18, 2009 at 01:02:54PM +, Neal Becker wrote: B has a reference to A. Could you be more specific? Where is this reference stored? In [1]: import numpy as np In [2]: a = np.empty(10) In [3]: b = a[::2] In [4]: b.base is a Out[4]: True Gaƫl

Re: [Numpy-discussion] views and object lifetime

2009-02-18 Thread Scott Sinclair
2009/2/18 Neal Becker ndbeck...@gmail.com: Matthieu Brucher matthieu.brucher at gmail.com writes: B has a reference to A. Could you be more specific? Where is this reference stored? What C api functions are used? I'm probably not qualified to be much more specific, these links should

Re: [Numpy-discussion] views and object lifetime

2009-02-18 Thread Travis E. Oliphant
Neal Becker wrote: How is it ensured, at the C api level, that when I have an array A, and a view of it B, that the data is not destroyed until both A and B are? One array, A, owns the data and will deallocate it only when its reference-count goes to 0.The view, B, has a reference to A

Re: [Numpy-discussion] Compute multiple outer products, without a loop?

2009-02-18 Thread Ken Basye
Thanks Chuck; that's perfect. Ken -- Message: 1 Date: Tue, 17 Feb 2009 11:04:56 -0700 From: Charles R Harris charlesr.har...@gmail.com Subject: Re: [Numpy-discussion] Compute multiple outer products without a

Re: [Numpy-discussion] Warnings in current trunk

2009-02-18 Thread Charles R Harris
On Tue, Feb 17, 2009 at 11:37 PM, David Cournapeau da...@ar.media.kyoto-u.ac.jp wrote: Charles R Harris wrote: Oh, and this should be avoided: if (endptr != NULL) *endptr = (char*)p; Folks have different views about whether the single statement should be in brackets but no

[Numpy-discussion] Ironclad v0.8.1 released

2009-02-18 Thread William Reade
Hi all I'm fairly pleased to announce the release of Ironclad v0.8.1; it's not an enormous technical leap above v0.8, but it does now enable you to import and use SciPy and Matplotlib with IronPython on Win32 (with some restrictions; see project page) . Downloads, and more details, are

[Numpy-discussion] additional dtype argument to numpy.dot() (Re: Numpy-discussion Digest, Vol 29, Issue 48)

2009-02-18 Thread David Henderson
Hi Paul, list: Thanks for the reply. numpy.sum() does indeed have a dtype for the accumulator for the sum. numpy.sum() does not implement an inner (dot) product, just a straight summation. The feature I'm requesting is to add a similar accumulator type argument for numpy.dot(). After

Re: [Numpy-discussion] additional dtype argument to numpy.dot() (Re: Numpy-discussion Digest, Vol 29, Issue 48)

2009-02-18 Thread David Cournapeau
On Thu, Feb 19, 2009 at 2:37 AM, David Henderson dav...@ipac.caltech.edu wrote: Hi Paul, list: Thanks for the reply. numpy.sum() does indeed have a dtype for the accumulator for the sum. numpy.sum() does not implement an inner (dot) product, just a straight summation. You may be

[Numpy-discussion] rgb_to_hsv in scipy.misc ? (was: Optimizing speed for large-array inter-element algorithms (specifically, color space conversion))

2009-02-18 Thread Nicolas Pinto
Hello, Would it be possible to include the following rgb to hsv conversion code in scipy (probably in misc along with misc.imread, etc.) ? What do you think? Thanks in advance. Best regards, -- Nicolas Pinto Ph.D. Candidate, Brain Computer Sciences Massachusetts Institute of Technology, USA

[Numpy-discussion] parallel compilation of numpy

2009-02-18 Thread Ondrej Certik
Hi, I have a shiny new computer with 8 cores and numpy still takes forever to compile --- is there a way to compile it in parallel (make -j9)? Do distutils allow that? If not, let's move to some build system that allows that? Just wanted to check if there is some reason for that, apart from

Re: [Numpy-discussion] parallel compilation of numpy

2009-02-18 Thread Robert Kern
On Wed, Feb 18, 2009 at 18:14, Ondrej Certik ond...@certik.cz wrote: Hi, I have a shiny new computer with 8 cores and numpy still takes forever to compile --- is there a way to compile it in parallel (make -j9)? Do distutils allow that? No. numscons will, though. If not, let's move to

Re: [Numpy-discussion] parallel compilation of numpy

2009-02-18 Thread Sturla Molden
I have a shiny new computer with 8 cores and numpy still takes forever to compile Yes, forever/8 = forever. Sturla Molden ___ Numpy-discussion mailing list Numpy-discussion@scipy.org http://projects.scipy.org/mailman/listinfo/numpy-discussion

Re: [Numpy-discussion] parallel compilation of numpy

2009-02-18 Thread Matthew Miller
On Thu, Feb 19, 2009 at 02:50:01AM +0100, Sturla Molden wrote: I have a shiny new computer with 8 cores and numpy still takes forever to compile Yes, forever/8 = forever. Good point. nan_to_num() could be helpful here. -- Matthew Miller mat...@mattdm.org

Re: [Numpy-discussion] parallel compilation of numpy

2009-02-18 Thread David Cournapeau
On Thu, Feb 19, 2009 at 9:14 AM, Ondrej Certik ond...@certik.cz wrote: Hi, I have a shiny new computer with 8 cores and numpy still takes forever to compile Forever ? It takes one minute to build :) scipy takes for ever, but it is because of C++ more than anything else. --- is there a way

Re: [Numpy-discussion] parallel compilation of numpy

2009-02-18 Thread David Cournapeau
On Thu, Feb 19, 2009 at 10:50 AM, Sturla Molden stu...@molden.no wrote: I have a shiny new computer with 8 cores and numpy still takes forever to compile Yes, forever/8 = forever. Not if you are a physician: my impression in undergrad was that infinity / 8 could be anything from 0 to

Re: [Numpy-discussion] parallel compilation of numpy

2009-02-18 Thread Ryan May
On Wed, Feb 18, 2009 at 8:00 PM, David Cournapeau courn...@gmail.comwrote: On Thu, Feb 19, 2009 at 10:50 AM, Sturla Molden stu...@molden.no wrote: I have a shiny new computer with 8 cores and numpy still takes forever to compile Yes, forever/8 = forever. Not if you are a physician:

Re: [Numpy-discussion] parallel compilation of numpy

2009-02-18 Thread David Cournapeau
On Thu, Feb 19, 2009 at 11:07 AM, Ryan May rma...@gmail.com wrote: Not to nitpick, but this is the second time I've seen this lately: physician == medical doctor != physicist :) You're right of course - the French word for physicist being physicien, it may be one more mistake perpetuated by

Re: [Numpy-discussion] parallel compilation of numpy

2009-02-18 Thread Christian Heimes
David Cournapeau wrote: No, and it never will. Parallel builds requires to build with dependency handling. Even make does not handle it well: it works most of the time by accident, but there are numerous problems (try for example building lapack with make -j8 on your 8 cores machine - it will

Re: [Numpy-discussion] parallel compilation of numpy

2009-02-18 Thread Ryan May
On Wed, Feb 18, 2009 at 8:19 PM, David Cournapeau courn...@gmail.comwrote: On Thu, Feb 19, 2009 at 11:07 AM, Ryan May rma...@gmail.com wrote: Not to nitpick, but this is the second time I've seen this lately: physician == medical doctor != physicist :) You're right of course - the

[Numpy-discussion] linalg.norm along axis?

2009-02-18 Thread Grissiom
Hi all, Is there any possibility to calculate norm along axis? For example: a = np.array(( (3,4), (6,8))) And I want to get: array([5.0, 10.0]) I currently use a for loop to achieve this, Is there any more elegant way to do this? -- Cheers, Grissiom

Re: [Numpy-discussion] parallel compilation of numpy

2009-02-18 Thread David Cournapeau
Christian Heimes wrote: David Cournapeau wrote: No, and it never will. Parallel builds requires to build with dependency handling. Even make does not handle it well: it works most of the time by accident, but there are numerous problems (try for example building lapack with make -j8 on

Re: [Numpy-discussion] linalg.norm along axis?

2009-02-18 Thread Nicolas Pinto
Grissiom, Using the following doesn't require any loop: In [9]: sqrt((a**2.).sum(1)) Out[9]: array([ 5., 10.]) Best, On Wed, Feb 18, 2009 at 10:23 PM, Grissiom chaos.pro...@gmail.com wrote: Hi all, Is there any possibility to calculate norm along axis? For example: a = np.array((

Re: [Numpy-discussion] linalg.norm along axis?

2009-02-18 Thread Grissiom
On Thu, Feb 19, 2009 at 12:12, Nicolas Pinto pi...@mit.edu wrote: Grissiom, Using the following doesn't require any loop: In [9]: sqrt((a**2.).sum(1)) Out[9]: array([ 5., 10.]) Best, Got it~ Thanks really ;) -- Cheers, Grissiom ___

Re: [Numpy-discussion] parallel compilation of numpy

2009-02-18 Thread David Cournapeau
Michael Abshoff wrote: David Cournapeau wrote: Christian Heimes wrote: David Cournapeau wrote: Hi, You may call me naive and ignorant. Is it really that hard to archive some kind of poor man's concurrency? You don't have to parallelize everything to get a speed up on

Re: [Numpy-discussion] parallel compilation of numpy

2009-02-18 Thread Michael Abshoff
David Cournapeau wrote: Michael Abshoff wrote: David Cournapeau wrote: Hi David, With Sage we do the cythonization in parallel and for now build extension serially, but we have code to do that in parallel, too. Given that we are building 180 extensions or so the speedup is linear. I often

Re: [Numpy-discussion] parallel compilation of numpy

2009-02-18 Thread David Cournapeau
Michael Abshoff wrote: Sure, it also works for incremental builds and I do that many, many times a day, i.e. for each patch I merge into the Sage library. What gets recompiled is decided by our own dependency tracking code which we want to push into Cython itself. Figuring out dependencies

Re: [Numpy-discussion] parallel compilation of numpy

2009-02-18 Thread Andrew Straw
David Cournapeau wrote: * Integration with setuptools and eggs, which enables things like namespace packages. This is not. eggs are not specified, and totally implementation defined. I tried some time ago to add an egg builder to scons, but I gave up. And I don't think you can reuse

Re: [Numpy-discussion] parallel compilation of numpy

2009-02-18 Thread David Cournapeau
On Thu, Feb 19, 2009 at 3:24 PM, Andrew Straw straw...@astraw.com wrote: David Cournapeau wrote: * Integration with setuptools and eggs, which enables things like namespace packages. This is not. eggs are not specified, and totally implementation defined. I tried some time ago to add an

Re: [Numpy-discussion] parallel compilation of numpy

2009-02-18 Thread Michael Abshoff
David Cournapeau wrote: Michael Abshoff wrote: Hi David, Sure, it also works for incremental builds and I do that many, many times a day, i.e. for each patch I merge into the Sage library. What gets recompiled is decided by our own dependency tracking code which we want to push into

Re: [Numpy-discussion] parallel compilation of numpy

2009-02-18 Thread Andrew Straw
David Cournapeau wrote: On Thu, Feb 19, 2009 at 3:24 PM, Andrew Straw straw...@astraw.com wrote: It's an interesting idea to build Python package distributions without distutils. For pure Python installables, if all you seek better is distutils, the bar seems fairly low. :) Being

Re: [Numpy-discussion] parallel compilation of numpy

2009-02-18 Thread David Cournapeau
On Thu, Feb 19, 2009 at 4:26 PM, Andrew Straw straw...@astraw.com wrote: Maybe if you need a level of backward compatibility, (and really, to gain a decent audience for this idea, I think you do need some level of backward compatibility) the new tool could emit setup.py files for consumption