Hi Wolfgang,
Thank you so much for your kind help. I tried the dynamic sparsity pattern,
and with the sparsity_pattern.add_entries() and sparse_matrix.set()
function, I sucesefully insert values in the sparse matrix.
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Hi Juan Carlos Araújo Cabarcas,
Thank you for your code, and it is really an excellent way. I also tried to
use the dynamic sparsity pattern in dealii, and use the add_entries()
function to indicate the nonzeros' locations, then I successfully insert
the values in the sparse matrix as you did in
In addition to the excellent idea by Juan Carlos:
> When I initialize the PETSc sparsity matrix, I don't know where the nonzeros
> are.
> Then I loop over the locally owned cells on each processor, and guadually
> know
> for each row of the matrix the locations and values of the nonzeros. Do
Hey Pai Liu,
At some point in my research I had to do something similar to what you want
to do. In the application of the so-called Dirichlet-to-Neumann maps for
Helmholtz problems, one has to assemble a dense block corresponding to the
boundary degrees of freedom, so I had to include extra ent
Hi Wolfgang,
> I would start by asking where the nonzero entries are going to lie. What
> kind of operator do you plan on implementing for which you don't know
> where the nonzeros are?
>
I want to multiply this matrix with a PETSc vector (which is also stored in
parallel).
When I initializ
On 4/2/19 9:28 AM, Pai Liu wrote:
>
> I need to manually create a PETSc sparsity matrix (not the system
> matrix) in parallel computing for other purposes.
I would start by asking where the nonzero entries are going to lie. What
kind of operator do you plan on implementing for which you don't k
Hi all,
I need to manually create a PETSc sparsity matrix (not the system matrix)
in parallel computing for other purposes. I only know the number of nonzero
values per row before I initialize the sparsity matrix. Thus I use the
following codes to initialize the PETSc sparsity matrix and add en
