[petsc-dev] [petsc-users] ublas sparse matrix bindings?

[Aron Ahmadia]

There are no "easy" solutions, but this is definitely Eigen3 territory...

A

On Mon, Jul 5, 2010 at 5:05 PM, Matthew Knepley <knepley at gmail.com> wrote:

> On Mon, Jul 5, 2010 at 3:50 PM, Jed Brown <jed at 59a2.org> wrote:
>
>> On Sat, 3 Jul 2010 15:41:53 +0300, Aron Ahmadia <aja2111 at columbia.edu>
>> wrote:
>> > I am not sure I  understand your argument here (I apologize if I talk
>> past
>> > you, please feel free to clarify).  I am surmising from the rest of your
>> > paragraph that you feel it would be most beneficial to users to have the
>> > full flexibility of mixed-precision with matrices/vectors, i.e. A = A1 +
>> A2,
>> > where A1 is single-precision and A2 is double-precision.  The layer at
>> which
>> > you express your linear algebra algorithms should be unaware of the data
>> > that composes a given matrix A.
>>
>> Consider a sparse matrix consisting of 12x12 blocks operating on vector
>> blocks with 3 single precision reals, 6 double precision reals, and 3
>> double precision complex.  Now write a templated factorization that
>> operates on these (user-defined) blocks.  Ideally this would merely
>> involve the user defining
>>
>>  struct Field {
>>    float a[3];
>>    double b[6];
>>    complex double c[3];
>>  };
>>  Matrix<int64_t,Field,Field> A;
>>
>> but I don't know how to make that work.  All I can think of is an
>> expression template solution operating on recursive types, which strikes
>> me as terribly confusing to write and use, as well as perhaps having
>> padding and ordering issues.
>
>
> Can we think up an easy DSL or library solution?
>
>    Matt
>
>
>>
>> Jed
>
> --
> What most experimenters take for granted before they begin their
> experiments is infinitely more interesting than any results to which their
> experiments lead.
> -- Norbert Wiener
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20100705/817be68c/attachment.html>