Hi all,
I am having a similar problem. I want to take a 3x3 BlockSparseMatrix m33
and copy four of its blocks into a 2x2 BlockSparseMatrix m22. For instance:
m33 = [ A B C
D E F
G H I ]
>From this matrix, I would like to obtain the following:
m22 = [ E F
Dear Wolfgang,
Thank you for your explanation. Currently, I am using a code that was not
written by me, and uses the MatrixTools::apply_boundary_values() approach.
I try to change it to use the ConstraintMatrix one. For that, step-40 seems
to be the best starting point, like Mark did.
Thanks agai
On 10/13/2017 08:39 AM, Lucas Campos wrote:
In general, using MatrixTools::apply_boundary_values() is not the way to go
with MPI programs. Rather, use a ConstraintMatrix and incorporate the
boundary
values into the same object as you do with hanging node constraints.
This is th
Dear Bangerth,
When you mention
In general, using MatrixTools::apply_boundary_values() is not the way to go
> with MPI programs. Rather, use a ConstraintMatrix and incorporate the
> boundary
> values into the same object as you do with hanging node constraints.
This is the way to go due to
On 10/13/2017 02:06 AM, Mark Ma wrote:
later, I changed the control into
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SolverControlsolver_control (5*system_rhs.size(),1e-12*system_rhs.l2_norm())
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this works well for structure size of um or nm. I think previous setting may
lead to a loss of precision so that the results are always i
Additional: Even though it compiles in release mode, as soon as I run it
with multiple nodes, I get a segfault at that place:
mpirun noticed that process rank 0 with PID 0 on node linux-lb8c exited on
signal 11 (Segmentation fault).
Am Freitag, 13. Oktober 2017 11:05:01 UTC+2 schrieb Maxi Mil
I try to apply initial values to a vector defined as
*LinearAlgebraTrilinos::MPI::Vector
*using
VectorTools::project (dof_handler, hanging_node_constraints,
QGauss(fe.degree+1),
InitialValues(),
local_solution);
When initializing the variable fe (as FESystem) with one or two
components, i
It is actually my stupid mistake in solvercontrol,
I used
SolverControl solver_control (dof_handler.n_dofs(),1e-12)
This works when the geometry size in the order of 1, but fails at 1e-6, or
even 1e-9. Here I actually want to make a micrometer or nanometer size
structure.
later, I changed the con
