2: /* seq.f -- translated by f2c (version of 25 March 1992 12:58:56).*/
4: #include <../src/mat/color/color.h>
8: PetscErrorCode MINPACKseq(PetscInt *n,const PetscInt *indrow,const PetscInt *jpntr,const PetscInt *indcol,const PetscInt *ipntr,PetscInt *list,PetscInt *ngrp,PetscInt *maxgrp,PetscInt *iwa) 9: {
10: /* System generated locals */
11: PetscInt i__1, i__2, i__3;
13: /* Local variables */
14: PetscInt jcol, j, ic, ip, jp, ir;
16: /* Given the sparsity pattern of an m by n matrix A, this */
17: /* subroutine determines a consistent partition of the */
18: /* columns of A by a sequential algorithm. */
19: /* A consistent partition is defined in terms of the loopless */
20: /* graph G with vertices a(j), j = 1,2,...,n where a(j) is the */
21: /* j-th column of A and with edge (a(i),a(j)) if and only if */
22: /* columns i and j have a non-zero in the same row position. */
23: /* A partition of the columns of A into groups is consistent */
24: /* if the columns in any group are not adjacent in the graph G. */
25: /* In graph-theory terminology, a consistent partition of the */
26: /* columns of A corresponds to a coloring of the graph G. */
27: /* The subroutine examines the columns in the order specified */
28: /* by the array list, and assigns the current column to the */
29: /* group with the smallest possible number. */
30: /* Note that the value of m is not needed by seq and is */
31: /* therefore not present in the subroutine statement. */
32: /* The subroutine statement is */
33: /* subroutine seq(n,indrow,jpntr,indcol,ipntr,list,ngrp,maxgrp, */
34: /* iwa) */
35: /* where */
36: /* n is a positive integer input variable set to the number */
37: /* of columns of A. */
38: /* indrow is an integer input array which contains the row */
39: /* indices for the non-zeroes in the matrix A. */
40: /* jpntr is an integer input array of length n + 1 which */
41: /* specifies the locations of the row indices in indrow. */
42: /* The row indices for column j are */
43: /* indrow(k), k = jpntr(j),...,jpntr(j+1)-1. */
44: /* Note that jpntr(n+1)-1 is then the number of non-zero */
45: /* elements of the matrix A. */
46: /* indcol is an integer input array which contains the */
47: /* column indices for the non-zeroes in the matrix A. */
48: /* ipntr is an integer input array of length m + 1 which */
49: /* specifies the locations of the column indices in indcol. */
50: /* The column indices for row i are */
51: /* indcol(k), k = ipntr(i),...,ipntr(i+1)-1. */
52: /* Note that ipntr(m+1)-1 is then the number of non-zero */
53: /* elements of the matrix A. */
54: /* list is an integer input array of length n which specifies */
55: /* the order to be used by the sequential algorithm. */
56: /* The j-th column in this order is list(j). */
57: /* ngrp is an integer output array of length n which specifies */
58: /* the partition of the columns of A. Column jcol belongs */
59: /* to group ngrp(jcol). */
60: /* maxgrp is an integer output variable which specifies the */
61: /* number of groups in the partition of the columns of A. */
62: /* iwa is an integer work array of length n. */
63: /* Argonne National Laboratory. MINPACK Project. July 1983. */
64: /* Thomas F. Coleman, Burton S. Garbow, Jorge J. More' */
67: /* Parameter adjustments */
68: --iwa;
69: --ngrp;
70: --list;
71: --ipntr;
72: --indcol;
73: --jpntr;
74: --indrow;
76: /* Function Body */
77: *maxgrp = 0;
78: i__1 = *n;
79: for (jp = 1; jp <= i__1; ++jp) {
80: ngrp[jp] = *n;
81: iwa[jp] = 0;
82: }
84: /* Beginning of iteration loop. */
86: i__1 = *n;
87: for (j = 1; j <= i__1; ++j) {
88: jcol = list[j];
90: /* Find all columns adjacent to column jcol. */
92: /* Determine all positions (ir,jcol) which correspond */
93: /* to non-zeroes in the matrix. */
95: i__2 = jpntr[jcol + 1] - 1;
96: for (jp = jpntr[jcol]; jp <= i__2; ++jp) {
97: ir = indrow[jp];
99: /* For each row ir, determine all positions (ir,ic) */
100: /* which correspond to non-zeroes in the matrix. */
102: i__3 = ipntr[ir + 1] - 1;
103: for (ip = ipntr[ir]; ip <= i__3; ++ip) {
104: ic = indcol[ip];
106: /* Array iwa marks the group numbers of the */
107: /* columns which are adjacent to column jcol. */
109: iwa[ngrp[ic]] = j;
110: }
111: }
113: /* Assign the smallest un-marked group number to jcol. */
115: i__2 = *maxgrp;
116: for (jp = 1; jp <= i__2; ++jp) {
117: if (iwa[jp] != j) goto L50;
118: }
119: ++(*maxgrp);
120: L50:121: ngrp[jcol] = jp;
122: }
124: /* End of iteration loop. */
125: return(0);
126: }