Actual source code: degree.c


  2: /* degree.f -- translated by f2c (version 19931217).*/

  4: #include <petsc/private/matorderimpl.h>

  6: /*****************************************************************/
  7: /*********     DEGREE ..... DEGREE IN MASKED COMPONENT   *********/
  8: /*****************************************************************/

 10: /*    PURPOSE - THIS ROUTINE COMPUTES THE DEGREES OF THE NODES*/
 11: /*       IN THE CONNECTED COMPONENT SPECIFIED BY MASK AND ../../..*/
 12: /*       NODES FOR WHICH MASK IS ZERO ARE IGNORED.*/

 14: /*    INPUT PARAMETER -*/
 15: /*       ../../.. - IS THE INPUT NODE THAT DEFINES THE COMPONENT.*/
 16: /*       (XADJ, ADJNCY) - ADJACENCY STRUCTURE PAIR.*/
 17: /*       MASK - SPECIFIES A SECTION SUBGRAPH.*/

 19: /*    OUTPUT PARAMETERS -*/
 20: /*       DEG - ARRAY CONTAINING THE DEGREES OF THE NODES IN*/
 21: /*             THE COMPONENT.*/
 22: /*       CCSIZE-SIZE OF THE COMPONENT SPECIFIED BY MASK AND ../../..*/
 23: /*    WORKING PARAMETER -*/
 24: /*       LS - A TEMPORARY VECTOR USED TO STORE THE NODES OF THE*/
 25: /*              COMPONENT LEVEL BY LEVEL.*/
 26: /*****************************************************************/
 27: PetscErrorCode SPARSEPACKdegree(const PetscInt *root, const PetscInt *inxadj, const PetscInt *adjncy, PetscInt *mask, PetscInt *deg, PetscInt *ccsize, PetscInt *ls)
 28: {
 29:   PetscInt *xadj = (PetscInt *)inxadj; /* Used as temporary and reset within this function */
 30:   /* System generated locals */
 31:   PetscInt i__1, i__2;

 33:   /* Local variables */
 34:   PetscInt ideg, node, i, j, jstop, jstrt, lbegin, lvlend, lvsize, nbr;
 35:   /*       INITIALIZATION ...*/
 36:   /*       THE ARRAY XADJ IS USED AS A TEMPORARY MARKER TO*/
 37:   /*       INDICATE WHICH NODES HAVE BEEN CONSIDERED SO FAR.*/

 39:   PetscFunctionBegin;
 40:   /* Parameter adjustments */
 41:   --ls;
 42:   --deg;
 43:   --mask;
 44:   --adjncy;
 45:   --xadj;

 47:   ls[1]       = *root;
 48:   xadj[*root] = -xadj[*root];
 49:   lvlend      = 0;
 50:   *ccsize     = 1;
 51: /*       LBEGIN IS THE POINTER TO THE BEGINNING OF THE CURRENT*/
 52: /*       LEVEL, AND LVLEND POINTS TO THE END OF THIS LEVEL.*/
 53: L100:
 54:   lbegin = lvlend + 1;
 55:   lvlend = *ccsize;
 56:   /*       FIND THE DEGREES OF NODES IN THE CURRENT LEVEL,*/
 57:   /*       AND AT THE SAME TIME, GENERATE THE NEXT LEVEL.*/
 58:   i__1 = lvlend;
 59:   for (i = lbegin; i <= i__1; ++i) {
 60:     node  = ls[i];
 61:     jstrt = -xadj[node];
 62:     i__2  = xadj[node + 1];
 63:     jstop = (PetscInt)PetscAbsInt(i__2) - 1;
 64:     ideg  = 0;
 65:     if (jstop < jstrt) goto L300;
 66:     i__2 = jstop;
 67:     for (j = jstrt; j <= i__2; ++j) {
 68:       nbr = adjncy[j];
 69:       if (!mask[nbr]) goto L200;
 70:       ++ideg;
 71:       if (xadj[nbr] < 0) goto L200;
 72:       xadj[nbr] = -xadj[nbr];
 73:       ++(*ccsize);
 74:       ls[*ccsize] = nbr;
 75:     L200:;
 76:     }
 77:   L300:
 78:     deg[node] = ideg;
 79:   }
 80:   /*       COMPUTE THE CURRENT LEVEL WIDTH. */
 81:   /*       IF IT IS NONZERO, GENERATE ANOTHER LEVEL.*/
 82:   lvsize = *ccsize - lvlend;
 83:   if (lvsize > 0) goto L100;
 84:   /*       RESET XADJ TO ITS CORRECT SIGN AND RETURN. */
 85:   i__1 = *ccsize;
 86:   for (i = 1; i <= i__1; ++i) {
 87:     node       = ls[i];
 88:     xadj[node] = -xadj[node];
 89:   }
 90:   PetscFunctionReturn(PETSC_SUCCESS);
 91: }