1: #include <petsc-private/matimpl.h>      /*I "petscmat.h"  I*/

  5: PETSC_EXTERN PetscErrorCode MatColoringApply_Power(MatColoring mc,ISColoring *iscoloring)
  6: {
  7:   PetscErrorCode  ierr;
  8:   Mat             m = mc->mat,mp,ms;
  9:   MatColoring     imc;
 10:   PetscInt        i;
 11:   const char      *optionsprefix;

 14:   /* square the matrix repeatedly if necessary */
 15:   if (mc->dist == 1) {
 16:     mp = m;
 17:   } else {
 18:     MatMatMult(m,m,MAT_INITIAL_MATRIX,2.0,&mp);
 19:     for (i=2;i<mc->dist;i++) {
 20:       ms = mp;
 21:       MatMatMult(m,ms,MAT_INITIAL_MATRIX,2.0,&mp);
 22:       MatDestroy(&ms);
 23:     }
 24:   }
 25:   MatColoringCreate(mp,&imc);
 26:   PetscObjectGetOptionsPrefix((PetscObject)mc,&optionsprefix);
 27:   PetscObjectSetOptionsPrefix((PetscObject)imc,optionsprefix);
 28:   PetscObjectAppendOptionsPrefix((PetscObject)imc,"power_");
 29:   MatColoringSetType(imc,MATCOLORINGGREEDY);
 30:   MatColoringSetDistance(imc,1);
 31:   MatColoringSetWeightType(imc,mc->weight_type);
 32:   MatColoringSetFromOptions(imc);
 33:   MatColoringApply(imc,iscoloring);
 34:   MatColoringDestroy(&imc);
 35:   if (mp != m) {MatDestroy(&mp);}
 36:   return(0);
 37: }

 41: /*MC
 42:   MATCOLORINGPOWER - Take the matrix's nth power, then do one-coloring on it.

 44:    Level: beginner

 46:    Notes:
 47:    This is merely a trivial test algorithm.

 49: .seealso: MatColoringCreate(), MatColoring, MatColoringSetType()
 50: M*/
 51: PETSC_EXTERN PetscErrorCode MatColoringCreate_Power(MatColoring mc)
 52: {
 54:   mc->ops->apply          = MatColoringApply_Power;
 55:   mc->ops->view           = NULL;
 56:   mc->ops->destroy        = NULL;
 57:   mc->ops->setfromoptions = NULL;
 58:   return(0);
 59: }