Actual source code: genrcm.c

  1: #define PETSCMAT_DLL

  3: /* genrcm.f -- translated by f2c (version 19931217).*/

 5:  #include petsc.h

  7: /*****************************************************************/
  8: /*****************************************************************/
  9: /*********   GENRCM ..... GENERAL REVERSE CUTHILL MCKEE   ********/
 10: /*****************************************************************/

 12: /*    PURPOSE - GENRCM FINDS THE REVERSE CUTHILL-MCKEE*/
 13: /*       ORDERING FOR A GENERAL GRAPH. FOR EACH CONNECTED*/
 14: /*       COMPONENT IN THE GRAPH, GENRCM OBTAINS THE ORDERING*/
 15: /*       BY CALLING THE SUBROUTINE RCM.*/

 17: /*    INPUT PARAMETERS -*/
 18: /*       NEQNS - NUMBER OF EQUATIONS*/
 19: /*       (XADJ, ADJNCY) - ARRAY PAIR CONTAINING THE ADJACENCY*/
 20: /*              STRUCTURE OF THE GRAPH OF THE MATRIX.*/

 22: /*    OUTPUT PARAMETER -*/
 23: /*       PERM - VECTOR THAT CONTAINS THE RCM ORDERING.*/

 25: /*    WORKING PARAMETERS -*/
 26: /*       MASK - IS USED TO MARK VARIABLES THAT HAVE BEEN*/
 27: /*              NUMBERED DURING THE ORDERING PROCESS. IT IS*/
 28: /*              INITIALIZED TO 1, AND SET TO ZERO AS EACH NODE*/
 29: /*              IS NUMBERED.*/
 30: /*       XLS - THE INDEX VECTOR FOR A LEVEL STRUCTURE.  THE*/
 31: /*              LEVEL STRUCTURE IS STORED IN THE CURRENTLY*/
 32: /*              UNUSED SPACES IN THE PERMUTATION VECTOR PERM.*/

 34: /*    PROGRAM SUBROUTINES -*/
 35: /*       FN../../.., RCM.*/
 36: /*****************************************************************/
 39: PetscErrorCode SPARSEPACKgenrcm(PetscInt *neqns,PetscInt *xadj,PetscInt *adjncy,PetscInt *perm,PetscInt *mask,PetscInt *xls)
 40: {
 41:     /* System generated locals */
 42:     PetscInt i__1;

 44:     /* Local variables */
 45:     PetscInt nlvl,root,i,ccsize;
 46:     EXTERN PetscErrorCode SPARSEPACKfnroot(PetscInt*,PetscInt *,PetscInt *,PetscInt *,PetscInt *,PetscInt *,PetscInt *),
 47:                SPARSEPACKrcm(PetscInt*,PetscInt *,PetscInt *,PetscInt *,PetscInt *,PetscInt *,PetscInt *);
 48:     PetscInt num;

 51:     /* Parameter adjustments */
 52:     --xls;
 53:     --mask;
 54:     --perm;
 55:     --adjncy;
 56:     --xadj;

 58:     i__1 = *neqns;
 59:     for (i = 1; i <= i__1; ++i) {
 60:         mask[i] = 1;
 61:     }
 62:     num = 1;
 63:     i__1 = *neqns;
 64:     for (i = 1; i <= i__1; ++i) {
 65: /*          FOR EACH MASKED CONNECTED COMPONENT ...*/
 66:         if (!mask[i]) {
 67:             goto L200;
 68:         }
 69:         root = i;
 70: /*             FIRST FIND A PSEUDO-PERIPHERAL NODE ../../...*/
 71: /*             NOTE THAT THE LEVEL STRUCTURE FOUND BY*/
 72: /*             FN../../.. IS STORED STARTING AT PERM(NUM).*/
 73: /*             THEN RCM IS CALLED TO ORDER THE COMPONENT*/
 74: /*             USING ../../.. AS THE STARTING NODE.*/
 75:         SPARSEPACKfnroot(&root,&xadj[1],&adjncy[1],&mask[1],&nlvl,&xls[1],&perm[num]);
 76:         SPARSEPACKrcm(&root,&xadj[1],&adjncy[1],&mask[1],&perm[num],&ccsize,&xls[1]);
 77:         num += ccsize;
 78:         if (num > *neqns) {
 79:             return(0);
 80:         }
 81: L200:
 82:         ;
 83:     }
 84:     return(0);
 85: }