[SciPy-Dev] sparse rmatvec and maxentropy

[josef.pktd at gmail.com]

On Sat, Jan 22, 2011 at 8:50 AM, Ralf Gommers
<ralf.gommers at googlemail.com> wrote:
>
>
> On Thu, Jan 20, 2011 at 10:13 PM, Skipper Seabold <jsseabold at gmail.com>
> wrote:
>>
>> On Tue, Jan 18, 2011 at 8:12 PM,  <josef.pktd at gmail.com> wrote:
>> > On Tue, Jan 18, 2011 at 8:05 PM,  <josef.pktd at gmail.com> wrote:
>> >> I don't know much about these two parts of scipy.
>> >>
>> >> Running an example for scipy.maxentropy raises an exception after
>> >> upgrading to scipy trunk
>> >>
>> >> I didn't manage to find out with a  Trac search whether rmatvec still
>> >> exists.
>> >>
>
> It was removed in r6996. I missed this one call to it, will clean it up.
>
>>
>> >
>> > 3 of the 4 examples in scipy/maxentropy/examples raise an exception. 2
>> > of them with the rmatvec not found error. The other one doesn't find
>> > scipy.sandbox
>> >
>>
>> I remember seeing the deprecation warnings for this now, but I never
>> worked much with the bigmodel.  I think you can just use * now instead
>> of the rmatvec for the sparse matrices.  You can see this in 0.8.0
>> where both are still there.
>
> A.rmatvec(v) should be A.conj().transpose() * v. But that does not make the
> examples work, they just fail later on. The one that imports scipy.sandbox
> hasn't worked for a while either.
>>
>> http://projects.scipy.org/scipy/browser/tags/0.8.0/scipy/sparse/base.py
>>
>> I picked up the montecarlo code when I was playing around with these.
>>
>>
>> http://bazaar.launchpad.net/~jsseabold/statsmodels/statsmodels-skipper-maxent/files/head:/scikits/statsmodels/sandbox/maxentropy/
>>
>> I'm curious if the maxentropy stuff as it is in scipy wouldn't find
>> more use and maintenance in scikits.learn.  The implementation is
>> somewhat use specific (natural language processing), though this is
>> not by any means set in stone.
>>
> Probably, but wouldn't it need a lot of work before it could be moved? It
> has a grand total of one test, mostly non-working examples, and is obviously
> hardly used at all (see r6919 and r6920 for more examples of broken code).
>
> Perhaps it's worth asking the scikits.learn guys, and otherwise consider
> deprecating it if they're not interested?

I haven't seen or heard anyone using it besides Skipper. There are
also still some features that where designed for pysparse and never
fully updated to scipy.sparse.
http://projects.scipy.org/scipy/ticket/856

I also thought deprecating and removing maxentropy will be the best
idea, if nobody volunteers to give it a workout.

Josef


>
> Cheers,
> Ralf
>
>
>
>
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