Re: ASCII file format for sparse matrices?

[Rui Maciel]

On 05/13/2011 02:06 PM, Jordi Gutiérrez Hermoso wrote:
> Probably not, unless they are your plans. This is the source file that
> you can begin inspecting to provide a patch:
>
>       
> http://hg.savannah.gnu.org/hgweb/octave/file/tip/src/ov-base-sparse.cc#l396
>
> Note that most of the work is done in op>>  here:
>
>       
> http://hg.savannah.gnu.org/hgweb/octave/file/tip/liboctave/dSparse.cc#l7599
>
> Which as you can see, is just a thin wrapper of the actual
> read_sparse_matrix function:
>
>       http://hg.savannah.gnu.org/hgweb/octave/file/tip/liboctave/Sparse.h#l586
>
> The actual sparse representation right now only is CCS. It would
> probably take a significant amount of rewriting much of the sparse
> matrix code if you have another representation in mind. However, if
> all you want is to extend the flexibility of the load command, that
> can probably be arranged.
I've just took a peek at the source code and, at least at first glance, 
it doesn't look like it takes that much work to implement a proper 
"dictionary of keys" format.  Well, it won't take that much work 
provided that it's possible to declare a temporary std::list for the DoK 
coefficients, import all [i,j,value] triplets into that list, sort the 
list in order of j and i and then fill the Sparse<T>& a object as before.

So, basically if it's possible to add a std::list dependency to 
liboctave/Sparse.h then I believe I can pull it off.

Any thoughts?


Rui Maciel