Mailman 3 July 2009 - SciPy-Dev

random.set_state also in need of EXPERT attention
by David Goldsmith July 28, 2009

July 28, 2009

Hi, folks! Ralf originally requested expert attention for this in its Discussion section; I over-confidently said I thought I could handle it; after too many hours of unproductive research (I seem to have found that there's a lot of "politics" in the field of random number generators? Despite widespread use: http://en.wikipedia.org/wiki/Mersenne_twister, Matsumoto & Nishimura and this algorithm don't appear to have much recognition in certain circles, e.g., those under the influence of Marsaglia, e.g., notably, "Numerical Recipes." I understand that Marsaglia is critical of MT, but for "NR" to completely ignore an algorithm in such widespread use, well, out of curiosity, if anyone knows, "what gives"?) I give up. DG

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docs and doceditor question
by josef.pktd＠gmail.com July 28, 2009

July 28, 2009

what is the source for http://docs.scipy.org/doc/scipy/reference/generated/scipy.interpolate.Univa… ? It's the kind of class documentation that I wanted but I don't see how it is generated. Is it autogenerated or are there specific directives somewhere to specify it. another question: Are the scipy docs supposed to build on Windows. I managed some months ago, but it seems I will have to hunt down again posix specific commands for several hours, to build it. I tried briefly, but without the latest sphinx. Thanks, Josef

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Re: [SciPy-dev] Milestones status update
by David Goldsmith July 28, 2009

July 28, 2009

Why you? DG --- On Tue, 7/28/09, Pierre GM <pgmdevlist(a)gmail.com> wrote: > From: Pierre GM <pgmdevlist(a)gmail.com> > Subject: Re: [SciPy-dev] Milestones status update > To: "SciPy Developers List" <scipy-dev(a)scipy.org> > Date: Tuesday, July 28, 2009, 2:02 PM > > On Jul 28, 2009, at 4:36 PM, d_l_goldsmith(a)yahoo.com > wrote: > > > > > Un-led categories not near "Goal met": > > > > "Masked Arrays," "Masked Arrays IV," "Operations on > Masks," "Even > > More MA Functions, I and II," "Other Math," "Other > Array > > Subclasses," "Numpy Internals," and "C-Types" (these > last two are > > noted as (probably) needing Expert attention). > > Uh-oh, looks like I'm in trouble... > > > _______________________________________________ > Scipy-dev mailing list > Scipy-dev(a)scipy.org > http://mail.scipy.org/mailman/listinfo/scipy-dev >

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Milestones status update
by d_l_goldsmith＠yahoo.com July 28, 2009

July 28, 2009

Un-led categories not near "Goal met": "Masked Arrays," "Masked Arrays IV," "Operations on Masks," "Even More MA Functions, I and II," "Other Math," "Other Array Subclasses," "Numpy Internals," and "C-Types" (these last two are noted as (probably) needing Expert attention). Led categories still needing work: "Financial Functions," (> 50% GM) "Random Number Generation," (> 57% GM) "Masked Arrays III" (> 80% GM). Objects & namespaces w/ "white" un-categorized attributes: broadcast, arrayprint (one), chararray (many!), matrix (many!), memmap, multiarray, numeric (Expert only?), recarray, record, scalarmath, umath, ctypeslib (one, Expert only!), distutils (many, Expert only!), doc, dtype (one), fftpack_lite, generic (many!), arrayterator, scimath, shape_base (one), stride_tricks, utils, testing (decorators, nosetester, utils), ufunc (one), void DG

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Re: [SciPy-dev] random.set_state also in need of EXPERT attention
by David Goldsmith July 28, 2009

July 28, 2009

Okee-dokee, thanks! DG --- On Tue, 7/28/09, Robert Kern <robert.kern(a)gmail.com> wrote: > From: Robert Kern <robert.kern(a)gmail.com> > Subject: Re: [SciPy-dev] random.set_state also in need of EXPERT attention > To: "SciPy Developers List" <scipy-dev(a)scipy.org> > Date: Tuesday, July 28, 2009, 1:34 PM > On Tue, Jul 28, 2009 at 15:16, David > Goldsmith<d_l_goldsmith(a)yahoo.com> > wrote: > > > > --- On Tue, 7/28/09, Robert Kern <robert.kern(a)gmail.com> > wrote: > > > >> Goldsmith<d_l_goldsmith(a)yahoo.com> > >> wrote: > >> > > >> NR is old and stodgy. They don't cover the > state-of-the-art > >> for many arts. Ignore them. > > > > Understood. (Still, I'm looking at the 2007 edition > - very disappointing. Well, at least I know now not to > invest my money in a copy for myself.) > > > >> What "expert attention" is required? > > > > Quoting Ralf from the Discussion section: > "[random.set_state] needs some expert explanation of what > the tuple elements mean, and an example of how to use this > function to modify the generator state in a meaningful way. > [later] [Matsumoto/Nishimura, 1997] is reasonably clear, > there's a link to it on the Wikipedia page. I think it will > only give you elements 2 and 3 though, 4 and 5 were added > later in the implementation and I guess are for some of the > distributions in the random module. [Perhaps irrelevant if > one doesn't need to decipher the code to write an > intelligible docstring] The other difficulty is the > Pyrex/Cython source, a bit harder to read than plain > Python." > > What is wrong with the current docstring's explanation of > the tuple > elements? If anything, there should be less information. > People should > be treating it as an opaque object unless if they are in an > unusual > circumstance like trying to match an MT implementation in > another > language. In such a circumstance, they really need to go > source diving > and understand the code. No amount of documentation is > suitable for > that. > > But basically, element 4 is a boolean flag (encoded as an > int) for > whether element 5 is a cached value for the Gaussian > distribution or > not. The Gaussian generator generates two values at a time, > so we > return one and cache one and turn on the flag. The next > call returns > the cached value and turns off the flag. > > -- > Robert Kern > > "I have come to believe that the whole world is an enigma, > a harmless > enigma that is made terrible by our own mad attempt to > interpret it as > though it had an underlying truth." > -- Umberto Eco > _______________________________________________ > Scipy-dev mailing list > Scipy-dev(a)scipy.org > http://mail.scipy.org/mailman/listinfo/scipy-dev >

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Re: [SciPy-dev] random.set_state also in need of EXPERT attention
by David Goldsmith July 28, 2009

July 28, 2009

--- On Tue, 7/28/09, Robert Kern <robert.kern(a)gmail.com> wrote: > Goldsmith<d_l_goldsmith(a)yahoo.com> > wrote: > > > NR is old and stodgy. They don't cover the state-of-the-art > for many arts. Ignore them. Understood. (Still, I'm looking at the 2007 edition - very disappointing. Well, at least I know now not to invest my money in a copy for myself.) > What "expert attention" is required? Quoting Ralf from the Discussion section: "[random.set_state] needs some expert explanation of what the tuple elements mean, and an example of how to use this function to modify the generator state in a meaningful way. [later] [Matsumoto/Nishimura, 1997] is reasonably clear, there's a link to it on the Wikipedia page. I think it will only give you elements 2 and 3 though, 4 and 5 were added later in the implementation and I guess are for some of the distributions in the random module. [Perhaps irrelevant if one doesn't need to decipher the code to write an intelligible docstring] The other difficulty is the Pyrex/Cython source, a bit harder to read than plain Python." DG > > -- > Robert Kern > > "I have come to believe that the whole world is an enigma, > a harmless > enigma that is made terrible by our own mad attempt to > interpret it as > though it had an underlying truth." > -- Umberto Eco > _______________________________________________ > Scipy-dev mailing list > Scipy-dev(a)scipy.org > http://mail.scipy.org/mailman/listinfo/scipy-dev >

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special.nbdtrik
by Pierre GM July 28, 2009

July 28, 2009

All, I'm trying to find the sources of special.nbdtrik, but no avail so far. Any help would be greatly appreciated. P.

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Need to reschedule the Summer Marathon weekly Skypecon
by David Goldsmith July 27, 2009

July 27, 2009

Hi, folks. I can't do Wed. 19:00 UTC this week; please suggest alternate times - if no one does, I'll assume that no one wants to have a Skypecon this week either. DG

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scipy.special changes, npymath integration
by David Cournapeau July 26, 2009

July 26, 2009

Hi, A small email to indicate that I have merged a first set of changes in scipy.special, aimed at making scipy.special more portable (in particular on windows with MS compilers). This means the scipy trunk requires the last numpy svn (r7252 as I speak). cheers, David

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Homogenizing stats & mstats
by Pierre GM July 24, 2009

July 24, 2009

All, I was browsing some recent tickets for scipy.stats, and couldn't but noticed that a significant number of them (#845, #822, #901...), are related to some lack of consistency between stats and mstats. I'd like to eventually get rid of mstats all together, provided the same functionalities are supported in stats. * A first step would be to use np.asanyarray instead of np.asarray. That should be sufficient for functions like gmean and hmean for example. * A second step would be to use numpy.ma under the hood, returning either a MaskedArray if the input is a MaskedArray itself, or just a standard ndarray otherwise. That should take care of the functions related to ranking and tie handling (I'm pretty confident into the mstats routines, and we can always double-check the results w/ R). If needed, we could also add a usemask flag, like we do in np.io.genfromtxt. * A third would be to port the remaining routines of mstats.extras to stats or morestats (Harrell-Davies quantiles could be imlemented more efficiently in cython, for example). At each step, we could add a Deprecate warning to a reviewed mstat function and call the corresponding stat function instead. What would be a good time line ? 0.8.0, or is it too late? 0.9.0 ? Comments expected. Thx in advance P.

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