Re: [Numpy-discussion] picking elements with boolean masks
Neal Becker wrote: starting with a NxM array, I want to select elements of the array using a set of boolean masks. The masks are simply where the indexes have a 0 or 1 in the corresponding bit position. For example, consider the case where M = 4. all_syms = np.arange (4) all_bits = np.arange (2) bit_mask = (all_syms[:,np.newaxis] all_bits) 1 mask0 = bit_mask == 0 mask1 = bit_mask == 1 Maybe there's a more straightforward way to generate these masks. That's not my question. In [331]: mask1 Out[331]: array([[False, False], [ True, False], [False, True], [ True, True]], dtype=bool) OK, now I want to use this mask on D In [333]: D.shape Out[333]: (32400, 4) Just to simplify, let's just try the first row of D In [336]: D[0] Out[336]: array([ 0., 2., 2., 4.]) In [335]: D[0][mask1[...,0]] Out[335]: array([ 2., 4.]) that worked fine. But I want not just to apply one of the masks in the set (mask1 is [4,2], it has 2 masks), I want the results of applying all the masks (2 in this case) In [334]: D[0][mask1] --- ValueErrorTraceback (most recent call last) ipython-input-334-243c7a5e45a4 in module() 1 D[0][mask1] ValueError: boolean index array should have 1 dimension Any ideas what's the best approach here? Perhaps what I need is to use integer indexing, rather than boolean. all_syms = np.arange (const.size) all_bits = np.arange (BITS_PER_SYM) bit_mask = (all_syms[:,np.newaxis] all_bits) 1 ind = np.array ([np.nonzero (bit_mask[...,i])[0] for i in range (BITS_PER_SYM)]) In [366]: ind Out[366]: array([[1, 3], [2, 3]]) So now we have the 1-d indexes of the elements we want to select from D. D = np.arange (4)+1 In [376]: D Out[376]: array([1, 2, 3, 4]) In [377]: D[ind] Out[377]: array([[2, 4], [3, 4]]) Looks like that does the job ___ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
Re: [Numpy-discussion] numpy array to C API
On Thu, Mar 21, 2013 at 05:34:51PM +0100, Valentin Haenel wrote: I got currious about the Ctypes approach as well as Gaël Varoquaux’s blog post about avoiding data copies, but the link in the article didn't seem to work. (Under Further Reading and References) There seems to be something wrong with Gaël's website. I have CC him, maybe he can fix it. Thanks Valentin! I believe that I have fixed the problem. Soren, if you still have difficulties accessing the material, please complain. Cheers, Gaël ___ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
Re: [Numpy-discussion] Unable to building numpy with openblas usingbento or distutils
Caveat: Not tested but it did look interesting: http://osdf.github.com/blog/numpyscipy-with-openblas-for-ubuntu-1204-second-try.html. Would be interested to know if it worked out as want to try out OpenBlas in the future.___ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
Re: [Numpy-discussion] Unable to building numpy with openblas usingbento or distutils
On Mon, Mar 25, 2013 at 2:40 PM, Dinesh B Vadhia dineshbvad...@hotmail.comwrote: ** Caveat: Not tested but it did look interesting: http://osdf.github.com/blog/numpyscipy-with-openblas-for-ubuntu-1204-second-try.html . Would be interested to know if it worked out as want to try out OpenBlas in the future. Yes, this is one of the sources I used. I needed to change the c_check file in openblas as described up thread, and I didn't like the half-distutils/half-bento hack, but with Ake's patch to numpy's distutils, and my site.cfg, this works as described for me (Kubuntu 12.10) using just the usual setup.py. Skipper ___ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
[Numpy-discussion] Growing the contributor base of Numpy
Dear all, One recurring question is how to *grow the contributor base* to NumPy and provide help and relief to core developers and maintainers. One way to do this would be to *leverage the upcoming SciPy conference* in 2 ways: 1. Provide an intermediate or advanced level tutorial on NumPy focusing on teaching the C-API and the architecture of the package to help people navigate the source code, and find answers to precise deep questions. I think that many users would be interested in being better able to understand the underlayers to become powerful users (and contributors if they want to). 2. Organize a Numpy sprint to leverage all this freshly graduated students apply what they learned to tackle some of the work under the guidance of core developers. This would be a great occasion to share and grow knowledge that is fundamental to our community. And the fact that the underlayers are in C is fine IMHO: SciPy is about scientific programming in Python and that is done with a lot of C. *Thoughts? Anyone interested in leading a tutorial (can be a team of people)? Anyone willing to coordinate the sprint? Who would be willing to be present and help during the sprint? * Note that there is less than 1 week left until the tutorial submission deadline. I am happy to help brainstorm on this to make it happen. Thanks, Jonathan and Andy, for the SciPy2013 organizers -- Jonathan Rocher, PhD Scientific software developer SciPy2013 conference co-chair Enthought, Inc. jroc...@enthought.com 1-512-536-1057 http://www.enthought.com ___ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
Re: [Numpy-discussion] variables not defined in numpy.random __init.py__ ?
On Mon, Mar 25, 2013 at 4:23 PM, Dinesh B Vadhia dineshbvad...@hotmail.comwrote: ** Using PyInstaller, the following error occurs: Traceback (most recent call last): File string, line 9, in module File //usr/lib/python2.7/dist-packages/PIL/Image.py, line 355, in init __import__(f, globals(), locals(), []) File //usr/lib/python2.7/dist-packages/PIL/IptcImagePlugin.py, line 23, in module import os, tempfile File /usr/lib/python2.7/tempfile.py, line 34, in module from random import Random as _Random File //usr/lib/python2.7/dist-packages/numpy/random/__init__.py, line 90, in module ranf = random = sample = random_sample NameError: name 'random_sample' is not defined Is line 90 in __init.py__ valid? It is. Above the failing you see a line from info import __all__, and in random/info.py you'll see that `random_sample` is in the __all__ dict. Somehow it disappeared for you, you'll need to do some debugging to find out why. Ralf ___ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
Re: [Numpy-discussion] variables not defined in numpy.random __init.py__ ?
On Mon, Mar 25, 2013 at 12:51 PM, Ralf Gommers ralf.gomm...@gmail.comwrote: On Mon, Mar 25, 2013 at 4:23 PM, Dinesh B Vadhia dineshbvad...@hotmail.com wrote: ** Using PyInstaller, the following error occurs: Traceback (most recent call last): File string, line 9, in module File //usr/lib/python2.7/dist-packages/PIL/Image.py, line 355, in init __import__(f, globals(), locals(), []) File //usr/lib/python2.7/dist-packages/PIL/IptcImagePlugin.py, line 23, in module import os, tempfile File /usr/lib/python2.7/tempfile.py, line 34, in module from random import Random as _Random File //usr/lib/python2.7/dist-packages/numpy/random/__init__.py, line 90, in module ranf = random = sample = random_sample NameError: name 'random_sample' is not defined Is line 90 in __init.py__ valid? It is. In my reading of this the main problem is that `tempfile` is trying to import `random` from the Python standard library but instead is importing the one from within NumPy (i.e., `numpy.random`). I suspect that somehow `sys.path` is being set incorrectly --- perhaps because of the `PYTHONPATH` environment variable. -Brad ___ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
Re: [Numpy-discussion] NumPy/SciPy participation in GSoC 2013
On Thu, Mar 21, 2013 at 10:20 PM, Ralf Gommers ralf.gomm...@gmail.comwrote: Hi all, It is the time of the year for Google Summer of Code applications. If we want to participate with Numpy and/or Scipy, we need two things: enough mentors and ideas for projects. If we get those, we'll apply under the PSF umbrella. They've outlined the timeline they're working by and guidelines at http://pyfound.blogspot.nl/2013/03/get-ready-for-google-summer-of-code.html. We should be able to come up with some interesting project ideas I'd think, let's put those at http://projects.scipy.org/scipy/wiki/SummerofCodeIdeas. Preferably with enough detail to be understandable for people new to the projects and a proposed mentor. We need at least 3 people willing to mentor a student. Ideally we'd have enough mentors this week, so we can apply to the PSF on time. If you're willing to be a mentor, please send me the following: name, email address, phone nr, and what you're interested in mentoring. If you have time constaints and have doubts about being able to be a primary mentor, being a backup mentor would also be helpful. So far we've only got one primary mentor (thanks Chuck!), most core devs do not seem to have the bandwidth this year. If there are other people interested in mentoring please let me know. If not, then it looks like we're not participating this year. Ralf ___ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
