[petsc-users] snes setjacobian with csr sparse matrix

[Adolfo Rodriguez]

I am trying to use PETSc to solve a non-linear problem. The problem I am
facing is that I already have the Jacobian matrix formed in CSR format. Now
I am trying to define a function FormJacobian which takes this preexisting
matrix and writes it in PETSc format. For a small problem, I can use
MatSetValue, looping over all non-zero elements one at a time. However,
this turns out too slow for larger problems.

In my current implementation, I am using MatCreateSeqAIJ which works great.
However, this approach does not seem to work to set the Jacobian.

Any suggestions?

Regards,

Adolfo
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