[petsc-users] getinfo for Mat of type nest

[Edoardo alinovi]

Hi Barry,

I am trying to port this preconditioner I found presented at the last PETSc
conference into may code:
https://urldefense.us/v3/__https://github.com/ndjinga/SOLVERLAB/blob/master/CoreFlows/examples/C/SaddlePointPreconditioner/SaddlePointLinearSolver.c__;!!G_uCfscf7eWS!a-JnrBsta75n_WDtxUNd7Xb8_m7tg1pWSxwWNTmUBSfpBwISq4IxJkbM6QgADd-x23Q_2s-d6d6bOWCKGRMxMzHyc9DDm7A$ 

So far so good, I am just translating C to Fortran, however when I try to
solve my linear system with:

call KSPSetOperators(ksp,  Ahat, Pmat, ierr)
call KSPSolve(ksp, bhat, xhat, ierr)

with Ahat and Pmat being indeed two nest MatNest, created from an array of
Mat as:

call MatCreateNest(PETSC_COMM_WORLD, 2, PETSC_NULL_IS, 2, PETSC_NULL_IS,
Mat_array,  Ahat, ierr)
call MatCreateNest(PETSC_COMM_WORLD, 2, PETSC_NULL_IS, 2, PETSC_NULL_IS,
Mat_array, Pmat, ierr)


However I am getting this error on getinfo:

from C to Fortran

[0]PETSC ERROR: --------------------- Error Message
--------------------------------------------------------------
[0]PETSC ERROR: No support for this operation for this object type
[0]PETSC ERROR: No method getinfo for Mat of type nest
[0]PETSC ERROR: See https://urldefense.us/v3/__https://petsc.org/release/faq/__;!!G_uCfscf7eWS!a-JnrBsta75n_WDtxUNd7Xb8_m7tg1pWSxwWNTmUBSfpBwISq4IxJkbM6QgADd-x23Q_2s-d6d6bOWCKGRMxMzHyRUMnyvE$  for trouble shooting.
[0]PETSC ERROR: Petsc Release Version 3.20.4, unknown

How can I get rid of this issue?

Many thanks!
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20241003/e42dd937/attachment-0001.html>