Re: [Pysparse-users] Adding a column of a sparse matrix to a dense vector

[Artur P. <art...@gm...>]

Thank you for your help Daniel

I have downloaded it but it is asking for more modules from your project.

I will try to have a look and see if I can do something based on what
you did. In the meantime I will also have a look a pyTrilinos.

Thank you once again.

-artur palha

On Tue, Jun 17, 2008 at 11:33 AM, Artur Palha <art...@gm...> wrote:
> Hi to you all, I hope someone can help me.
>
> I am trying to do the following with pysparse but I am having problems doing it.
>
> I have a dense vector, say:
>
> x = numpy.arange(0,10)
>
> and a sparse matrix:
>
> A = pysparse.spmatrix.ll_mat(10,10)
>
> What I wish to do is:
>
> x = x + A[:, 2]
>
> But this gives the following error:
> TypeError: unsupported operand type(s) for +: 'float' and 'll_mat'
>
> Then I tried like this:
>
> x = numpy.arange(0,10)
>
> A = pysparse.sparray.sparray((10,10))
>
> With this it works ok but then, when I try to do a slice:
>
> A_reduced = A[0:5, 0:5]
>
> It gives an error:
> TypeError: unsupported operand type(s) for +: 'int' and 'slice'
>
> Anybody can give a help?
>
> Also, what is the main difference between spmatrix and sparray?
>
> Thanking in advance
>
> Best regards
>
> -artur palha
>