Re: [eigen] banded matrices in Eigen
• To: eigen@xxxxxxxxxxxxxxxxxxx
• Subject: Re: [eigen] banded matrices in Eigen
• From: Laura Flores <laura.floresanchez@xxxxxxxxx>
• Date: Fri, 7 Feb 2014 16:49:39 +0100
• Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :content-type; bh=mT//wc/BYJMOu6xtDKmIw3rDCyKLGVqVFsGnCOsHeK4=; b=OfPBHLS9m4T/umVaVD5LlIl0RGrEJkzxSnr3cfJMaJhnJ6dmKzhFCtEBFmqb8cDGjk VTtJyGX9Cnlx+mAaXGWpaQWQkzC0yNk5I33X7Jo8dOjmFoRN6+hn36E7BU0n82UkRVO2 6sFMOqc4j/bd1fpq1QsEPULl0306iWiFd5ZYghttaJXuQZo66g+NKMKTHv+vB7vX7o6a IxdzqkDbmgMFGQdKR4U/SNMt+Z0TsvmG/LE4vvJxv+YW9fbYYwgJgtPuqkO/ZWxmaCQU +E1YDvuaX2A2a8lR7mPx7ZWEnX6b2vyaOcXRuI4M0f44UXEF5+lcmP+fKf8/Im+c78l9 VVxw==

Hi Rhys,
Yes, I meant a sparse matrix with that kind of structure (symmetric and multi-diagonal). I was using a SparseMatrix, but maybe it is better to use something more similar to the Diagonal class.

Thinking of another approach, could somebody tell if it is possible to use the ThreadedConjugateGradient solver with a custom matrix (that is to say, a matrix class defined by myself)? Or maybe with a matrix which is derived from the Diagonal class?

Thank you,
Laura

2014-02-07 4:06 GMT+01:00 Rhys Ulerich :
Hi Laura,

> I would also be interested in sparse multi-diagonal symmetric matrices.. I am
> dealing with sparse matrices that are composed only of a certain number of
> diagonals, and, since they are symmetric, some of this diagonals are
> identical.

Just to be clear, do you mean dense, symmetric, banded a la BLAS SBMV?
Or do you mean a genuinely sparse matrix (so compressed storage of
some sort) that happens to exhibit the same structure?

> Has there been by any chance some improvement since the last question