Johan Hake wrote:
Question #105253 on DOLFIN changed:
https://answers.launchpad.net/dolfin/+question/105253
Status: Open => Answered
Johan Hake proposed the following answer:
On Monday 22 March 2010 20:04:47 Murtazo Nazarov wrote:
New question #105253 on DOLFIN:
https://answers.launchpad.net/dolfin/+question/105253
I am trying to use Lu factorized solver, for that did like this.
LUSolver solver("lu");
Matrix M;
Vector b;
assemble(M, *a);
assemble(b, *L);
solver.factorize(M);
solver.factorized_solve(u.vector(), b);
The matrix M is a mass matrix. But I get runtime error:
terminate called after throwing an instance of 'std::runtime_error'
what(): *** Error: Unable to return pointers to underlying matrix
data.
Did someone experienced such output? Do you know how to fix it?
I think Garth can give a more comprehensive answer, but it looks like
solver.factorize only works for the uBLAS backend. So you probably need
to
set:
parameters["linear_algebra_backend"] = "uBLAS";
in the beginning.
Johan
With this I get another error:
Initializing DOLFIN version 0.9.7.
Matrix of size 14400 x 14400 has 43200 nonzero entries.
Sorting sparsity pattern.
Matrix of size 14400 x 14400 has 43200 nonzero entries.
Sorting sparsity pattern.
LU-factorizing linear system of size 14400 x 14400 (UMFPACK).
[0]PETSC ERROR:
------------------------------------------------------------------------
[0]PETSC ERROR: Caught signal number 11 SEGV: Segmentation Violation,
probably memory access out of range
[0]PETSC ERROR: Try option -start_in_debugger or -on_error_attach_debugger
[0]PETSC ERROR: or see
http://www.mcs.anl.gov/petsc/petsc-as/documentation/troubleshooting.html#Si
gnal[0]PETSC ERROR: or try http://valgrind.org on linux or man libgmalloc
on Apple to find memory corruption errors
[0]PETSC ERROR: configure using --with-debugging=yes, recompile, link,
and run
[0]PETSC ERROR: to get more information on the crash.
[0]PETSC ERROR: --------------------- Error Message
------------------------------------
[0]PETSC ERROR: Signal received!
