Mailman 3 November 2009 - NumPy-Discussion

[OT] Python-URL! QOTW
by Bruce Southey Nov. 3, 2009

Nov. 3, 2009

Way to go Robert! QOTW: "I consider "import *" the first error to be fixed ..." - Robert Kern, author of PyFlakes, a potential replacement for Pylint and Pychecker, on his personal style http://groups.google.com/group/comp.lang.python/msg/5bf77b21b3b0caf2 Python 2.6.4 is out; it fixes some small but important bugs in previous 2.6.3 release: http://groups.google.com/group/comp.lang.python/t/44f4c166de5e6703/ PEP391: A new way to configure Python logging, using dictionaries: http://groups.google.com/group/comp.lang.python/t/3fc3138c22a50678/ Why do you use Python? http://groups.google.com/group/comp.lang.python/t/66ccb10d2da5b740/ Is there any value in forcing one class/function per module? (long thread): http://groups.google.com/group/comp.lang.python/t/1e0c1e2091539512/ A review of complex solutions to an almost inexistent problem shows constructive criticism in action: http://groups.google.com/group/comp.lang.python/t/d218212cabe9670b/ A user module may shadow a standard module of the same name - is it avoidable? http://groups.google.com/group/comp.lang.python/t/b31f74b6145c9d94/ copy.deepcopy() is not as "deep" as its name implies: http://groups.google.com/group/comp.lang.python/t/d827fd118189fe01/ A long thread about Web development: why to use templates, and why frameworks actually do help developers: http://groups.google.com/group/comp.lang.python/t/367025d4d9a2e15d/ Using a module as a place to store application global settings: http://groups.google.com/group/comp.lang.python/t/23e21edf1b232b32/ A simple list comprehension question leads to discuss mutability, identity, and Cousin Chuy's Super-Burritos: http://groups.google.com/group/comp.lang.python/t/17cfd91ece6ed54f/ Combining map, zip and filter into an equivalent list comprehension: http://groups.google.com/group/comp.lang.python/t/259976305282b0c0?q=map timeit: make sure you actually measure what you want, and not other code: http://groups.google.com/group/comp.lang.python/t/7ecae76e11f720ee/ Why do compiled C extensions on Windows use '.pyd' in their name instead of '.dll'? http://groups.google.com/group/comp.lang.python/t/c8d93871cc5f31dc/ Pyfora, a web forum about Python, was lauched recently. Will this fragment the community? http://groups.google.com/group/comp.lang.python/t/e6e0d99c995da697/ A guy's future book on programming Python doesn't fit standard practice (a long thread!): http://groups.google.com/group/comp.lang.python/t/6918784f36d147d2/ ======================================================================== Everything Python-related you want is probably one or two clicks away in these pages: Python.org's Python Language Website is the traditional center of Pythonia http://www.python.org Notice especially the master FAQ http://www.python.org/doc/FAQ.html PythonWare complements the digest you're reading with the marvelous daily python url http://www.pythonware.com/daily Just beginning with Python? This page is a great place to start: http://wiki.python.org/moin/BeginnersGuide/Programmers The Python Papers aims to publish "the efforts of Python enthusiasts": http://pythonpapers.org/ The Python Magazine is a technical monthly devoted to Python: http://pythonmagazine.com Readers have recommended the "Planet" site: http://planet.python.org comp.lang.python.announce announces new Python software. Be sure to scan this newsgroup weekly. http://groups.google.com/group/comp.lang.python.announce/topics Python411 indexes "podcasts ... to help people learn Python ..." Updates appear more-than-weekly: http://www.awaretek.com/python/index.html The Python Package Index catalogues packages. http://www.python.org/pypi/ Much of Python's real work takes place on Special-Interest Group mailing lists http://www.python.org/sigs/ Python Success Stories--from air-traffic control to on-line match-making--can inspire you or decision-makers to whom you're subject with a vision of what the language makes practical. http://www.pythonology.com/success The Python Software Foundation (PSF) has replaced the Python Consortium as an independent nexus of activity. It has official responsibility for Python's development and maintenance. http://www.python.org/psf/ Among the ways you can support PSF is with a donation. http://www.python.org/psf/donations/ The Summary of Python Tracker Issues is an automatically generated report summarizing new bugs, closed ones, and patch submissions. http://search.gmane.org/?author=status%40bugs.python.org&group=gmane.comp.p… Although unmaintained since 2002, the Cetus collection of Python hyperlinks retains a few gems. http://www.cetus-links.org/oo_python.html Python FAQTS http://python.faqts.com/ The Cookbook is a collaborative effort to capture useful and interesting recipes. http://code.activestate.com/recipes/langs/python/ Many Python conferences around the world are in preparation. Watch this space for links to them. Among several Python-oriented RSS/RDF feeds available, see: http://www.python.org/channews.rdf For more, see: http://www.syndic8.com/feedlist.php?ShowMatch=python&ShowStatus=all The old Python "To-Do List" now lives principally in a SourceForge reincarnation. http://sourceforge.net/tracker/?atid=355470&group_id=5470&func=browse http://www.python.org/dev/peps/pep-0042/ del.icio.us presents an intriguing approach to reference commentary. It already aggregates quite a bit of Python intelligence. http://del.icio.us/tag/python Enjoy the *Python Magazine*. http://pymag.phparch.com/ *Py: the Journal of the Python Language* http://www.pyzine.com Dr.Dobb's Portal is another source of Python news and articles: http://www.ddj.com/TechSearch/searchResults.jhtml?queryText=python and Python articles regularly appear at IBM DeveloperWorks: http://www.ibm.com/developerworks/search/searchResults.jsp?searchSite=dW&se… Previous - (U)se the (R)esource, (L)uke! - messages are listed here: http://search.gmane.org/?query=python+URL+weekly+news+links&group=gmane.com… http://groups.google.com/groups/search?q=Python-URL!+group%3Acomp.lang.pyth… http://lwn.net/Search/DoSearch?words=python-url&ctype3=yes&cat_25=yes There is *not* an RSS for "Python-URL!"--at least not yet. Arguments for and against are occasionally entertained. Suggestions/corrections for next week's posting are always welcome. E-mail to <Python-URL(a)phaseit.net> should get through. To receive a new issue of this posting in e-mail each Monday morning (approximately), ask <claird(a)phaseit.net> to subscribe. Mention "Python-URL!". Write to the same address to unsubscribe. -- The Python-URL! Team-- Phaseit, Inc. (http://phaseit.net) is pleased to participate in and sponsor the "Python-URL!" project. Watch this space for upcoming news about posting archives.

1 0

numpy distutils and cython
by Robert Cimrman Nov. 3, 2009

Nov. 3, 2009

Hi, I am using numpy distutils to build the extension modules of a project, which have been so far written in C, and wrapped by SWIG. Now I would like to try cython (as everynone!), but still be able to use the numpy distutils. I have found the thread [1], which offers some solution, but it does not mention using the Configuration class from numpy.distutils.misc_util which I use. How can I tell Configuration to use Cython instead of Pyrex? thanks! r. [1] http://old.nabble.com/problem-with-numpy.distutils-and-Cython-td25100957.ht…

1 0

Re: [Numpy-discussion] Setting a firm release date for 1st december.
by Tony S Yu Nov. 2, 2009

Nov. 2, 2009

On Nov 2, 2009, at 11:09 AM, numpy-discussion-request(a)scipy.org wrote: > From: David Cournapeau <cournape(a)gmail.com> > Subject: [Numpy-discussion] 1.4.0: Setting a firm release date for 1st > december. > To: Discussion of Numerical Python <numpy-discussion(a)scipy.org> > Message-ID: > <5b8d13220911020029q1d9f1bd7ia1770e3b93e6e653(a)mail.gmail.com> > Content-Type: text/plain; charset=UTF-8 > > Hi, > > I think it is about time to release 1.4.0. Instead of proposing a > release date, I am setting a firm date for 1st December, and 16th > november to freeze the trunk. If someone wants a different date, you > have to speak now. > > There are a few issues I would like to clear up: > - Documentation for datetime, in particular for the public C API > - Snow Leopard issues, if any > > Otherwise, I think there has been quite a lot of new features. If > people want to add new functionalities or features, please do it soon, > > cheers, > > David This seems like an appropriate opportunity to ping an issue I posted on Trac: http://projects.scipy.org/numpy/ticket/1177 Basically, interp doesn't currently play nice with numpy scalars. Patch included with ticket (see second comment). Cheers, -Tony

1 0

Re: [Numpy-discussion] odd behaviour with basic operations
by Benjamin Deschamps Nov. 2, 2009

Nov. 2, 2009

Seems like this was a rookie mistake with code later in the function. Thanks for suggesting the use of numpy.where, that is a much better function for the purpose. Benjamin

1 0

odd behaviour with basic operations
by Benjamin Deschamps Nov. 2, 2009

Nov. 2, 2009

I am getting strange behaviour with the following code: Pd = ((numpy.sign(C_02) == 1) * Pd_pos) + ((numpy.sign(C_02) == -1) * Pd_neg) Ps = ((numpy.sign(C_02) == 1) * Ps_pos) + ((numpy.sign(C_02) == -1) * Ps_neg) where Pd, Ps, C_02, Pd_pos, Pd_neg, Ps_pos and Ps_neg are all Float32 numpy arrays of the same shape. The problem is that the first line evaluates correctly (Pd is what it should be), but the second line does not. However, if I run the same line of code manually in IDLE, then it evaluates correctly! In other words, Ps as returned by the function does not match the value that I should get and obtain when entering the exact same code in IDLE. Basically, (numpy.sign(C_02) == 1) evaluates to either True or False, and multiplying with another array will give either 0 (when false) or the value of the array. The purpose of this code is to compute Pd and Ps without loops, and to take the value from Pd_pos or Ps_pos when C_02 is positive or of Pd_neg and Ps_neg when C_02 is negative. Using loops, it looks like this: for index in numpy.ndindex(ysize, xsize): if numpy.sign(C_02[index]) == 1: Pd[index] = Pd_pos[index] Ps[index] = Ps_pos[index] elif numpy.sign(C_02[index]) == -1: Pd[index] = Pd_neg[index] Ps[index] = Ps_neg[index] which also works fine, but takes much longer. Python 2.6.3, IDLE 2.6.1, Numpy 1.3.0, Snow Leopard, the script also uses some GDAL, matplotlib and scipy functions... Ideas? Benjamin

2 1

Single view on multiple arrays
by Bill Blinn Nov. 1, 2009

Nov. 1, 2009

What is the best way to create a view that is composed of sections of many different arrays? For example, imagine I had a = np.array(range(0, 12)).reshape(3, 4) b = np.array(range(12, 24)).reshape(3, 4) c = np.array(range(24, 36)).reshape(3, 4) v = multiview((3, 4)) #the idea of the following lines is that the 0th row of v is #a view on the first row of a. the same would hold true for #the 1st and 2nd row of v and the 0th rows of b and c, respectively v[0] = a[0] v[1] = b[0] v[2] = c[0] #change the underlying arrays a[0, 0] = 50 b[0, 0] = 51 c[0, 0] = 52 #I would want all these assertions to pass because the view #refers to the rows of a, b and c assert v[0, 0] == 50 assert v[1, 0] == 51 assert v[2, 0] == 52 Is there any way to do this? Thanks, bill

3 3

November 6 EPD Webinar: How do I... use Envisage for GUIs?
by Amenity Applewhite Nov. 1, 2009

Nov. 1, 2009

Having trouble viewing this email? Click here Friday, November 6: How do I... use Envisage for GUIs? Dear Leah, Envisage is a Python-based framework for building extensible applications. The Envisage Core and corresponding Envisage Plugins are components of the Enthought Tool Suite. We've found that Envisage grants us a degree of immediate functionality in our custom applications and have come to rely on the framework in much of our development. For November's EPD webinar, Corran Webster will show how you can hook together existing Envisage plugins to quickly create a new GUI. We'll also look at how you can easily turn an existing Traits UI interface into an Envisage plugin. New: Linux-ready webinars! In order to better serve the Linux-users among our subscribers, we've decided to begin hosting our EPD webinars on WebEx instead of GoToMeeting. This means that our original limit of 35 attendees will be scaled back to 30. As usual, EPD subscribers at a Basic level or above will be guaranteed seats for the event while the general public may add their name to the wait list here. EPD Webinar: How do I... use Envisage for GUIs? Friday, November 6 1pm CDT/6pm UTC Wait list We look forward to seeing you Friday! As always, feel free to contact us with questions, concerns, or suggestions for future webinar topics. Thanks, The Enthought Team QUICK LINKS ::: www.enthought.com code.enthought.com Facebook Enthought Blog Forward email This email was sent to leah(a)enthought.com by amenity(a)enthought.com. Update Profile/Email Address | Instant removal with SafeUnsubscribe™ | Privacy Policy. Enthought, Inc. | 515 Congress Ave. | Suite 2100 | Austin | TX | 78701

1 0

Recarray comparison and byte order
by Matthew Brett Nov. 1, 2009

Nov. 1, 2009

Hi, I was surprised by this - is it a bug or a feature or me misunderstanding something? a = np.zeros((1,), dtype=[('f1', 'u2')]) b = a.copy() b == a (array([True], dtype=bool)) # as expected c = a.byteswap().newbyteorder() c == a (False) # to me, unexpected, note bool rather than array Thanks for any clarification... Matthew

2 2