[SciPy-dev] the current state and future directions of the sparse solvers
Tue Apr 8 16:13:18 CDT 2008
On Tue, Apr 8, 2008 at 3:46 PM, Ondrej Certik <firstname.lastname@example.org> wrote:
> > Supporting a common interface to the various solvers would be quite
> > useful. However, like (2) we should not support interfaces to
> > optional libraries/methods.
> You mean support in scipy by default, right? I would like to have the
> unified interface to all solvers (including petsc and others).
I think that a common interface to UMFPACK/PETSc/etc. should live a scikit.
Ideally, the scikit would include those libraries itself.
> OK, that sounds very good. I am going to study how to start such a
> scikit and we are going to move our additional solvers we have in
> sfepy to it (pysparse, soon petsc4py) -- are you ok with that Robert?
> :) Plus umfpack. Plus the eigensolvers, like primme, blzpack and
I just recently saw a talk by some people that work on providing
abstract interfaces to the solvers in Trilinos:
I have no experience with these, but they may provide some guidance.
> And then we'll see how it goes and if some part is useful (like
> pysparse or blzpack) and with BSD license, it can later be moved to
> scipy directly.
> Do you have some idea about the interface? I noticed the
> linalg/interface.py, that's the way to go. This is only for the
> iterative solvers though.
LinearOperator was designed to formalize the interface expected by
I haven't thought about it much since then, so it's possible that
additions/modifications will be necessary.
> We need to devise some unified interface for the direct solvers and
> also for eigensolvers. Ok, I'll try to follow the arpack example and
> then we'll see if it's ok, or it needs some changes for example in the
> blzpack case.
> For example the lobpcg now in scipy has a different interface, doesn't it?
Only slightly. Since lobpcg operates on block vectors I added a
.matmat() to LinearOperator. If a operator provides a matvec()
method, but no matmat(), then the matvec() is applied to each column.
In the future some sparse matrices may have optimized matmat() for blockvectors.
Nathan Bell email@example.com
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