[petsc-users] MatMatSolve in sequential call

[Alexander Grayver]

On 13.08.2012 19:01, Hong Zhang wrote:
> Alexander :
> I need a simple code from you to reproduce the error for debugging.

Hong,

Attached you will find test.c that should reproduce this behavior with 
petsc-3.3-p2.
Just run it with 1 and 2 procs as following:
./mpirun -n 1 test -ksp_type preonly -pc_type cholesky 
-pc_factor_mat_solver_package mumps -ksp_view

Here is matrix I tested it on (15 MB): 
https://dl.dropbox.com/u/60982984/A.dat

> If mumps' solver is activated, then you should get error (sequential 
> and parallel)
> [0]PETSC ERROR: No support for this operation for this object type!
> [0]PETSC ERROR: MatMatSolve_MUMPS() is not implemented yet!
>
> If petsc's direct solver is activated, then you should not be able to 
> run it in parallel.

Please note, that it works correctly for nproc > 1 since 1 year or so!
So I don't quite understand why there should be error thrown.
I just occasionally decided to test something in sequential version and 
this thing happened.

>
> Please check ~petsc/src/mat/examples/tests/ex125.c
> to see if you used same calling procedure as this example.
> Note: I fixed a bug in this example and patched petsc-3.3.
> The update copy of ex125.c is attached for your convenience.
>
> Hong
>


-- 
Regards,
Alexander

-------------- next part --------------
#include <petscksp.h>
#include <petscviewer.h>

static char help = [];

#undef __FUNCT__
#define __FUNCT__ "main"
int main(int argc,char **args)
{
  Vec            x,b;
  Mat            A,B,C,F;
  KSP            ksp;    
  PC             pc;
  PetscRandom    rctx;
  PetscInt       M,N;
  PetscErrorCode ierr;
  PetscViewer    viewer;

  PetscInitialize(&argc,&args,(char *)0,help);

  ierr = PetscViewerBinaryOpen(PETSC_COMM_WORLD,"A.dat",FILE_MODE_READ,&viewer);CHKERRQ(ierr);
  ierr = MatCreate(PETSC_COMM_WORLD,&A);CHKERRQ(ierr);
  ierr = MatSetFromOptions(A);CHKERRQ(ierr);
  ierr = MatLoad(A,viewer);CHKERRQ(ierr);
  ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);

  MatGetSize(A,&N,&M);
  VecCreateMPI(PETSC_COMM_WORLD,PETSC_DECIDE,M,&x);
  VecCreateMPI(PETSC_COMM_WORLD,PETSC_DECIDE,N,&b);
  
  MatCreateDense(PETSC_COMM_WORLD,PETSC_DECIDE,PETSC_DECIDE,N,10,PETSC_NULL,&B);
  MatCreateDense(PETSC_COMM_WORLD,PETSC_DECIDE,PETSC_DECIDE,N,10,PETSC_NULL,&C);

  PetscRandomCreate(PETSC_COMM_WORLD,&rctx);
  PetscRandomSetFromOptions(rctx);
  VecSetRandom(b,rctx);

  ierr = KSPCreate(PETSC_COMM_WORLD,&ksp);CHKERRQ(ierr);
  ierr = KSPSetOperators(ksp,A,A,DIFFERENT_NONZERO_PATTERN);CHKERRQ(ierr);
  ierr = KSPSetFromOptions(ksp);CHKERRQ(ierr);
  ierr = KSPSolve(ksp,b,x);CHKERRQ(ierr);
  
  ierr = KSPGetPC(ksp,&pc);CHKERRQ(ierr);
  ierr = PCFactorGetMatrix(pc,&F);CHKERRQ(ierr);
  ierr = MatMatSolve(F,B,C);CHKERRQ(ierr);
  

  KSPDestroy(&ksp);
  MatDestroy(&A);
  MatDestroy(&B);
  MatDestroy(&C);
  VecDestroy(&x);
  VecDestroy(&b);
  PetscRandomDestroy(&rctx);

  ierr = PetscFinalize();

  return 0;
}