Actual source code: amd.c

  2: #include <petscmat.h>
  3: #include <../src/mat/order/order.h>
  4: #define UF_long long long
  5: #define UF_long_max LONG_LONG_MAX
  6: #define UF_long_id "%lld"
  7: #include <amd.h>

  9: #if defined(PETSC_USE_64BIT_INDICES)
 10: #  define amd_AMD_defaults amd_l_defaults
 11: #  define amd_AMD_order    amd_l_order
 12: #else
 13: #  define amd_AMD_defaults amd_defaults
 14: #  define amd_AMD_order    amd_order
 15: #endif

 18: /*
 19:     MatGetOrdering_AMD - Find the Approximate Minimum Degree ordering

 21:     This provides an interface to Tim Davis' AMD package (used by UMFPACK, CHOLMOD, MATLAB, etc).
 22: */
 25: PetscErrorCode  MatGetOrdering_AMD(Mat mat,const MatOrderingType type,IS *row,IS *col)
 26: {
 28:   PetscInt       nrow,*ia,*ja,*perm;
 29:   int            status;
 30:   PetscReal      val;
 31:   double         Control[AMD_CONTROL],Info[AMD_INFO];
 32:   PetscBool      tval,done;

 35:   /*
 36:      AMD does not require that the matrix be symmetric (it does so internally,
 37:      at least in so far as computing orderings for A+A^T.
 38:   */
 39:   MatGetRowIJ(mat,0,PETSC_FALSE,PETSC_TRUE,&nrow,&ia,&ja,&done);
 40:   if (!done) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"Cannot get rows for matrix type %s",((PetscObject)mat)->type_name);

 42:   amd_AMD_defaults(Control);
 43:   PetscOptionsBegin(((PetscObject)mat)->comm,((PetscObject)mat)->prefix,"AMD Options","Mat");
 44:   /*
 45:     We have to use temporary values here because AMD always uses double, even though PetscReal may be single
 46:   */
 47:   val = (PetscReal)Control[AMD_DENSE];
 48:   PetscOptionsReal("-mat_ordering_amd_dense","threshold for \"dense\" rows/columns","None",val,&val,PETSC_NULL);
 49:   Control[AMD_DENSE] = (double)val;

 51:   tval = (PetscBool)Control[AMD_AGGRESSIVE];
 52:   PetscOptionsBool("-mat_ordering_amd_aggressive","use aggressive absorption","None",tval,&tval,PETSC_NULL);
 53:   Control[AMD_AGGRESSIVE] = (double)tval;
 54:   PetscOptionsEnd();

 56:   PetscMalloc(nrow*sizeof(PetscInt),&perm);
 57:   status = amd_AMD_order(nrow,ia,ja,perm,Control,Info);
 58:   switch (status) {
 59:     case AMD_OK: break;
 60:     case AMD_OK_BUT_JUMBLED:
 61:       /* The result is fine, but PETSc matrices are supposed to satisfy stricter preconditions, so PETSc considers a
 62:       * matrix that triggers this error condition to be invalid.
 63:       */
 64:       SETERRQ(((PetscObject)mat)->comm,PETSC_ERR_PLIB,"According to AMD, the matrix has unsorted and/or duplicate row indices");
 65:     case AMD_INVALID:
 66:       amd_info(Info);
 67:       SETERRQ(((PetscObject)mat)->comm,PETSC_ERR_PLIB,"According to AMD, the matrix is invalid");
 68:     case AMD_OUT_OF_MEMORY:
 69:       SETERRQ(((PetscObject)mat)->comm,PETSC_ERR_MEM,"AMD could not compute ordering");
 70:     default:
 71:       SETERRQ(((PetscObject)mat)->comm,PETSC_ERR_LIB,"Unexpected return value");
 72:   }
 73:   MatRestoreRowIJ(mat,0,PETSC_FALSE,PETSC_TRUE,&nrow,&ia,&ja,&done);

 75:   ISCreateGeneral(PETSC_COMM_SELF,nrow,perm,PETSC_COPY_VALUES,row);
 76:   ISCreateGeneral(PETSC_COMM_SELF,nrow,perm,PETSC_OWN_POINTER,col);
 77:   return(0);
 78: }