Re: [ublas] Bad prod efficiency of sparse/symmetry matrix ?

From: Epic John (epicjohn_at_[hidden])
Date: 2006-12-08 17:37:51

What about sparse_prod? Should that ever be used instead of axpy_prod?When I
tried it, it seemed to run faster for sparse=sparse*sparse .
John

> My classmate ever demo Altas library for me.
> It's really fast when your matrix is bigger.
>
> any way, thanks a lot again
>
> If I am free ,I will try to test all kind  efficiency  of prod .
>
> Kuo-Shih
>
> Gunter Winkler wrote:
> >
> > On Friday 08 December 2006 15:59, Seabook wrote:
> >> I will try that but I still don't know how to use axpy_prod.
> >
> > 1) modify the line in operation.hpp marked with +/i in my diff
> > 2) use axpy_prod(A,X,Y,true) for Y = prod(A,X)
> >    and axpy_prod(A,X,Y,false) for Y += prod(A,X)
> >
> >> Could you paste your source code with axpy_prod operation?
> >
> > I should have atached it already :(
> >
> > BTW. ublas' product of dense matrices is a lot slower than any optimized
> > blas3
> > routine. However, you can use the atlas-bindings to use blas instead of
> > prod.
> >
> > mfg
> > Gunter
> >
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> >
> >
>
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