2: #include <petsc-private/pcimpl.h>   /*I "petscpc.h" I*/

  6: static PetscErrorCode PCApply_Mat(PC pc,Vec x,Vec y)
  7: {

 11:   MatMult(pc->pmat,x,y);
 12:   return(0);
 13: }

 17: static PetscErrorCode PCApplyTranspose_Mat(PC pc,Vec x,Vec y)
 18: {

 22:   MatMultTranspose(pc->pmat,x,y);
 23:   return(0);
 24: }

 28: static PetscErrorCode PCDestroy_Mat(PC pc)
 29: {
 31:   return(0);
 32: }

 34: /*MC
 35:      PCMAT - A preconditioner obtained by multiplying by the preconditioner matrix supplied
 36:              in PCSetOperators() or KSPSetOperators()

 38:    Notes:  This one is a little strange. One rarely has an explict matrix that approximates the
 39:          inverse of the matrix they wish to solve for.

 41:    Level: intermediate

 43: .seealso:  PCCreate(), PCSetType(), PCType (for list of available types), PC,
 44:            PCSHELL

 46: M*/

 50: PETSC_EXTERN PetscErrorCode PCCreate_Mat(PC pc)
 51: {
 53:   pc->ops->apply               = PCApply_Mat;
 54:   pc->ops->applytranspose      = PCApplyTranspose_Mat;
 55:   pc->ops->setup               = 0;
 56:   pc->ops->destroy             = PCDestroy_Mat;
 57:   pc->ops->setfromoptions      = 0;
 58:   pc->ops->view                = 0;
 59:   pc->ops->applyrichardson     = 0;
 60:   pc->ops->applysymmetricleft  = 0;
 61:   pc->ops->applysymmetricright = 0;
 62:   return(0);
 63: }