[SciPy-User] isn't it a bug in scipy.sparse? + some questions
Wed Nov 11 13:48:20 CST 2009
Le mercredi 11 novembre 2009 à 20:28 +0200, Dmitrey a écrit :
> So, anyone doesn't know answers to the questions about scipy.sparse
> module mentioned below?
> As for the bug mentioned, I have installed latest numpy & scipy svn
> snapshots (1.4.0.dev7726 and 0.8.0.dev6096), the bug still exist.
> --- Исходное сообщение ---
> От кого: "Dmitrey" <email@example.com>
> Кому: firstname.lastname@example.org
> Дата: 8 ноября, 13:22:34
> Тема: [SciPy-User] isn't it a bug in scipy.sparse? + some questions
> Hi scipy.sparse developers and all other scipy users,
> I'm trying to take benefits for solving SLEs in FuncDesigner
> via involving scipy.sparse.
> Some examples are here
> and example for sparse SLEs is here
> It already works faster than using dense matrices, but I want
> to speedup it even more, so I have some questions and seems
> like bug report (scipy.__version__ 0.7.0):
> from scipy import sparse
> from numpy import *
> a[0:3,:] = ones(3)
> print a.todense()
> [[ 1.]
> [ 0.]
> [ 0.]]
> while I expect all-ones
in this case, using:
a[0:3,:] = 1
will do what you want.
I don't know if it's really a bug.
> 1) Seems like a[some_ind,:]=something works very, very slow
> for lil. I have implemented a workaround, but can I use
> a[some_ind,:] for another format than lil? (seems like all
> other ones doesn't support it).
>From what I understand, lil format is useful for building matrices terms
by terms. As for advanced indexing operations, I guess coo format is
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