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Subject: Re: [ublas] [bindings] naming for sparse matrices
From: Thomas Klimpel (Thomas.Klimpel_at_[hidden])
Date: 2010-02-01 12:18:25

Rutger ter Borg wrote:
> If you agree, I'll make the appropriate adjustments,
> run all unit tests, and wrap up the sparse stuff
> so we can move on again.

If you want to do all the work :-)
I could also try to write it and do the necessary adjustments.

> Do we need an index_type<M>::type?

I don't know, but probably yes. In case the index_type of umfpack/mumps is not identical to index_type<M>::type, it looks like some conversion must be done.

> I've been pondering about this for a while. Given that we also have matrices
> like tridiagonal (3 arrays), and ones with data in associative arrays (which
> is just one array containing something else than "value"), I've come up with
> the following proposal that I actually like:
> begin_array1( ... ), end_array1( ... )
> begin_array2( ... ), etc.
> ...
> the contents of these arrays depend on the data structure.

Well, if you are sure that you like it, why not. What is the type of "*begin_array1( ... )"? Wouldn't it be better not to mix "index" and "numerical" data? The tridiagonal matrices requested by lapack are not always "true" tridiagonal matrices, because the off-diagonal sometimes has n-elements instead of n-1.