Hi Georg,
for the system that you describe, there is no need to wrap things in
BCRSMatrices and BlockVectors. You can use directly FieldMatrices and -Vectors:
Dune::FieldMatrix<Scalar, numSurfaceReactions, numSurfaceSpecies> A;
for(int speciesIdx=0; speciesIdx<numSurfaceSpecies; speciesIdx++)
for(int reactionIdx=0; reactionIdx<numSurfaceReactions;
reactionIdx++)
A[speciesIdx][reactionIdx] = ...
// right hand side
Dune::FieldVector<Scalar, numSurfaceReactions> b;
for(int reactionIdx=0; reactionIdx<numSurfaceReactions; reactionIdx++)
b[reactionIdx] = …
// solution
Dune::FieldVector<Scalar, numSurfaceSpecies> x;
A.solve(x, b);
I hope that numSurfaceReactions == numSurfaceSpecies?
You would only need the more complicated setting if your system size was not
known at compile time.
Kind regards
Bernd
________________________________
Von: Dumux <[email protected]> im Auftrag von
[email protected] <[email protected]>
Gesendet: Montag, 11. Dezember 2017 09:29:07
An: [email protected]
Betreff: [DuMuX] Dune::BCRSMatrix
Hello Dumux,
I would like to solve a linear system of equations (A*x = b) using the Dune
ISTL. To use the Dumux implementation (seqsolverbackend.hh),
Dune::FieldVectors need to be wrapped in Dune::Blockvectors and a
Dune::FieldMatrix is wrapped in a Dune::BCRSMatrix. I am not familiar with
these data types and the Dune documentation on the homepage is really
confusing. Since the system is not too large, I guess I can solve everything in
a single block? This is the code I use right now:
Dune::FieldMatrix<Scalar, numSurfaceReactions, numSurfaceSpecies> A;
for(int speciesIdx=0; speciesIdx<numSurfaceSpecies; speciesIdx++)
for(int reactionIdx=0; reactionIdx<numSurfaceReactions;
reactionIdx++)
assign values…
// right hand side
Dune::BlockVector<Dune::FieldVector<Scalar, numSurfaceReactions> > b;
b.resize(1); // does this mean there is only one block containing a
FieldVector ?
for(int reactionIdx=0; reactionIdx<numSurfaceReactions; reactionIdx++)
b[0][reactionIdx] = …
// solution
Dune::BlockVector<Dune::FieldVector<Scalar, numSurfaceSpecies> > x;
x.resize(1);
typedef typename Dune::FieldMatrix<Scalar, numSurfaceReactions,
numSurfaceSpecies> MatrixBlock;
typedef typename Dune::BCRSMatrix<MatrixBlock> ISTLMatrix;
ISTLMatrix A2(1, 1, ISTLMatrix::random); // does this mean there is only one
block containing a FieldMatrix ?
for(int speciesIdx=0; speciesIdx<numSurfaceSpecies; speciesIdx++)
for(int reactionIdx=0; reactionIdx<numSurfaceReactions;
reactionIdx++)
A2[0][0][reactionIdx][speciesIdx] = … HOW TO ASSIGN VALUES???
I get a segmentation fault from the last line. Is there better information on
BCRS matrices somewhere? Any hints on how to set up this matrix are greatly
appreciated!
Best regards
Georg Futter
——————————————————————————
German Aerospace Center (DLR)
Institute of Engineering Thermodynamics | Computational Electrochemistry |
Pfaffenwaldring 38-40 | 70569 Stuttgart
Dipl.-Ing. Georg Futter | Ph.D. student
Telefon 0711/6862-8135 | [email protected]<mailto:[email protected]>
www.DLR.de<http://www.dlr.de/>
_______________________________________________
Dumux mailing list
[email protected]
https://listserv.uni-stuttgart.de/mailman/listinfo/dumux
