SimplicialLDLT causes huge permutation fill-in from version 3.2.5 on

Submitted by hen..@..gmx.de

Assigned to Nobody

Link to original bugzilla bug (#1055)
Version: 3.2

Description

Hello Eigen Team,

I'm solving sparse matrices with the SimplicialLDLT with
SimplicialLDLT<SparseMatrix<double>,Lower> ldltsolver;

Everything works fine for Eigen version 3.2.4, but when I compile the exact same program using Eigen version 3.2.5 it causes a huge fill-in.

For the same Problem I get the same numerical result for the two different Eigen versions, but a very different result regarding matrix fill-in of the L Matrix after permutation with the analyzePattern() function. As a consequence the computation time of analyzePattern() and subsequent solve() is drastically increased.

I've tried both mingw 4.6.2 (GCC) and VisualStudio2010 with the same result.

Here is some output from my program code:

output from version 3.2.5:
-> nonzero entries before=1036 after=13600 decomposition => fillin is 13.1274 sparse matrix size(m/n)=320/320
computation time of analyzePattern()=686.601

output from version 3.2.4:
-> nonzero entries before=1036 after=1432 decomposition => fillin is 1.38224 sparse matrix size(m/n)=320/320
computation time of analyzePattern()=42.6205

Can you please check that issue and fix it for further versions?
If you need more Information, please let me know.
Thanks,
Mike.