Re: [Pysparse-users] Has the keys() method changed behavior?

[Toine B. <tb...@iv...>]

Thanks, that seems to have done the job! Thanks for the speedy response!

-Toine

> I reverted keys() back to its old behavior. I don't know why I changed
> it in the first place.  It's on branches/keys right now, so check it
> out and make sure it does what you want and I'll merge back to 
> branches/version-1_1 and trunk.
> 
> Can we tidy up branches by removing some of the dead wood in there?
> Can I delete 1_1_x, PSI, branch_numpy, branch_rel_1_0, class_branch,
> python-2_4?
> 
> On Tue, Aug 3, 2010 at 5:21 AM, Toine Bogers <tb...@iv...> wrote:
>> Dear PySparse maintainers,
>> First of all: thanks for creating PySparse! It's been extremely useful in
> writing my Python code for my collaborative filtering experiments. Up till
>> now I never really had any problems with it, but after I migrated to
>> v1.1.1 I ran into a peculiar 'bug/feature' with the keys() method.
>> I used to run v1.0 of PySparse on OS X 10.5 without any problems. I tried
>> installing the later versions, but they would never compile and the .dmg of
>> v1.0 on SourceForge worked fine for me. I recently migrated to Snow Leopard
>> (clean install) and to my surprise I could compile and install the latest
>> version of PySparse (v1.1.1) without any problems.
>> At first glance everything seemed to work just fine until I ran one of my
>> larger scripts. It returned a very peculiar error: the keys() method no
>> longer works as it should. Instead of returning a list of tuples of (row,
>> column)-indices it now returns a list containing two lists, one containing
>> all row indices, the other containing all column indices
>> The following example shows what I mean. I've created a small 3x3 sparse
>> matrix A:
>>>> print A
>> ll_mat(general, [3,3]):
>>  1.000000  2.000000  --------
>>  1.000000  1.000000  2.000000
>>  4.000000  5.000000  4.000000
>> Then when I print out the keys, it returns this:
>>>> print A.keys()
>> [[0, 0, 1, 1, 1, 2, 2, 2], [0, 1, 0, 1, 2, 0, 1, 2]]
>> whereas it used to return:
>> [[0, 0], [0, 1], [1, 0], [1, 1], [1, 2], [2, 0], [2, 1], [2, 2]]
>> And of course all of my code is expecting that method to work like that. The
>> online documentation still says that keys() returns "[...]a list of tuples
>> (i,j) of the nonzero matrix entries." Which is also what I expected it to
>> do, but not what it does anymore.
>> The strange thing is that the items() method still returns a list of
>> tuple-value pairs:
>>>> print A.items()
>> [((0, 0), 1.0), ((0, 1), 2.0), ((1, 0), 1.0), ((1, 1), 1.0), ((1, 2), 2.0),
>> ((2, 0), 4.0), ((2, 1), 5.0), ((2, 2), 4.0)]
>> In a way this is good, since it means I can, with some relatively minor
>> adjusments, use the items() method instead. But I would prefer not to have
>> to use items() when keys() is enough.
>> Do you have an explanation for the change in behavior I've observed? Is it
>> perhaps some sort of compilation option that I didn't set properly (which
>> makes the underlying Fortran/C-code return its results in a different format
>> to the keys() method)?
>>
>> Kind regards,
>> Toine Bogers
> 
> -- 
> Daniel Wheeler

----
Toine Bogers
Royal School of Library & Information Science
Birketinget 6 | 2300 Copenhagen S | Denmark
http://itlab.dbit.dk/~toine/
Phone: +45 32 34 13 67 | Room: C4.02