1: /* dsm.f -- translated by f2c (version of 25 March 1992 12:58:56). */
3: #include <../src/mat/color/color.h>
5: static PetscInt c_n1 = -1;
9: PetscErrorCode MINPACKdsm(PetscInt *m,PetscInt *n,PetscInt *npairs,PetscInt *indrow,PetscInt *indcol,PetscInt *ngrp,PetscInt *maxgrp, 10: PetscInt *mingrp,PetscInt *info,PetscInt *ipntr,PetscInt *jpntr,PetscInt *iwa,PetscInt *liwa) 11: {
12: /* System generated locals */
13: PetscInt i__1,i__2,i__3;
15: /* Local variables */
16: PetscInt i,j,maxclq,numgrp;
18: /* Given the sparsity pattern of an m by n matrix A, this */
19: /* subroutine determines a partition of the columns of A */
20: /* consistent with the direct determination of A. */
21: /* The sparsity pattern of the matrix A is specified by */
22: /* the arrays indrow and indcol. On input the indices */
23: /* for the non-zero elements of A are */
24: /* indrow(k),indcol(k), k = 1,2,...,npairs. */
25: /* The (indrow,indcol) pairs may be specified in any order. */
26: /* Duplicate input pairs are permitted, but the subroutine */
27: /* eliminates them. */
28: /* The subroutine partitions the columns of A into groups */
29: /* such that columns in the same group do not have a */
30: /* non-zero in the same row position. A partition of the */
31: /* columns of A with this property is consistent with the */
32: /* direct determination of A. */
33: /* The subroutine statement is */
34: /* subroutine dsm(m,n,npairs,indrow,indcol,ngrp,maxgrp,mingrp, */
35: /* info,ipntr,jpntr,iwa,liwa) */
36: /* where */
37: /* m is a positive integer input variable set to the number */
38: /* of rows of A. */
39: /* n is a positive integer input variable set to the number */
40: /* of columns of A. */
41: /* npairs is a positive integer input variable set to the */
42: /* number of (indrow,indcol) pairs used to describe the */
43: /* sparsity pattern of A. */
44: /* indrow is an integer array of length npairs. On input indrow */
45: /* must contain the row indices of the non-zero elements of A. */
46: /* On output indrow is permuted so that the corresponding */
47: /* column indices are in non-decreasing order. The column */
48: /* indices can be recovered from the array jpntr. */
49: /* indcol is an integer array of length npairs. On input indcol */
50: /* must contain the column indices of the non-zero elements of */
51: /* A. On output indcol is permuted so that the corresponding */
52: /* row indices are in non-decreasing order. The row indices */
53: /* can be recovered from the array ipntr. */
54: /* ngrp is an integer output array of length n which specifies */
55: /* the partition of the columns of A. Column jcol belongs */
56: /* to group ngrp(jcol). */
57: /* maxgrp is an integer output variable which specifies the */
58: /* number of groups in the partition of the columns of A. */
59: /* mingrp is an integer output variable which specifies a lower */
60: /* bound for the number of groups in any consistent partition */
61: /* of the columns of A. */
62: /* info is an integer output variable set as follows. For */
63: /* normal termination info = 1. If m, n, or npairs is not */
64: /* positive or liwa is less than max(m,6*n), then info = 0. */
65: /* If the k-th element of indrow is not an integer between */
66: /* 1 and m or the k-th element of indcol is not an integer */
67: /* between 1 and n, then info = -k. */
68: /* ipntr is an integer output array of length m + 1 which */
69: /* specifies the locations of the column indices in indcol. */
70: /* The column indices for row i are */
71: /* indcol(k), k = ipntr(i),...,ipntr(i+1)-1. */
72: /* Note that ipntr(m+1)-1 is then the number of non-zero */
73: /* elements of the matrix A. */
74: /* jpntr is an integer output array of length n + 1 which */
75: /* specifies the locations of the row indices in indrow. */
76: /* The row indices for column j are */
77: /* indrow(k), k = jpntr(j),...,jpntr(j+1)-1. */
78: /* Note that jpntr(n+1)-1 is then the number of non-zero */
79: /* elements of the matrix A. */
80: /* iwa is an integer work array of length liwa. */
81: /* liwa is a positive integer input variable not less than */
82: /* max(m,6*n). */
83: /* Subprograms called */
84: /* MINPACK-supplied ... degr,ido,numsrt,seq,setr,slo,srtdat */
85: /* FORTRAN-supplied ... max */
86: /* Argonne National Laboratory. MINPACK Project. December 1984. */
87: /* Thomas F. Coleman, Burton S. Garbow, Jorge J. More' */
90: /* Parameter adjustments */
91: --iwa;
92: --jpntr;
93: --ipntr;
94: --ngrp;
95: --indcol;
96: --indrow;
98: *info = 0;
100: /* Determine a lower bound for the number of groups. */
102: *mingrp = 0;
103: i__1 = *m;
104: for (i = 1; i <= i__1; ++i) {
105: /* Computing MAX */
106: i__2 = *mingrp,i__3 = ipntr[i + 1] - ipntr[i];
107: *mingrp = PetscMax(i__2,i__3);
108: }
110: /* Determine the degree sequence for the intersection */
111: /* graph of the columns of A. */
113: MINPACKdegr(n,&indrow[1],&jpntr[1],&indcol[1],&ipntr[1],&iwa[*n * 5 + 1],&
114: iwa[*n + 1]);
116: /* Color the intersection graph of the columns of A */
117: /* with the smallest-last (SL) ordering. */
119: MINPACKslo(n,&indrow[1],&jpntr[1],&indcol[1],&ipntr[1],&iwa[*n * 5 + 1],&
120: iwa[(*n << 2) + 1],&maxclq,&iwa[1],&iwa[*n + 1],&iwa[(*n << 1)
121: + 1],&iwa[*n * 3 + 1]);
122: MINPACKseq(n,&indrow[1],&jpntr[1],&indcol[1],&ipntr[1],&iwa[(*n << 2) + 1],
123: &ngrp[1],maxgrp,&iwa[*n + 1]);
124: *mingrp = PetscMax(*mingrp,maxclq);
126: /* Exit if the smallest-last ordering is optimal. */
128: if (*maxgrp == *mingrp) {
129: return(0);
130: }
132: /* Color the intersection graph of the columns of A */
133: /* with the incidence-degree (ID) ordering. */
135: MINPACKido(m,n,&indrow[1],&jpntr[1],&indcol[1],&ipntr[1],&iwa[*n * 5 + 1],
136: &iwa[(*n << 2) + 1],&maxclq,&iwa[1],&iwa[*n + 1],&iwa[(*n <<
137: 1) + 1],&iwa[*n * 3 + 1]);
138: MINPACKseq(n,&indrow[1],&jpntr[1],&indcol[1],&ipntr[1],&iwa[(*n << 2) + 1],
139: &iwa[1],&numgrp,&iwa[*n + 1]);
140: *mingrp = PetscMax(*mingrp,maxclq);
142: /* Retain the better of the two orderings so far. */
144: if (numgrp < *maxgrp) {
145: *maxgrp = numgrp;
146: i__1 = *n;
147: for (j = 1; j <= i__1; ++j) {
148: ngrp[j] = iwa[j];
149: }
151: /* Exit if the incidence-degree ordering is optimal. */
153: if (*maxgrp == *mingrp) {
154: return(0);
155: }
156: }
158: /* Color the intersection graph of the columns of A */
159: /* with the largest-first (LF) ordering. */
161: i__1 = *n - 1;
162: MINPACKnumsrt(n,&i__1,&iwa[*n * 5 + 1],&c_n1,&iwa[(*n << 2) + 1],&iwa[(*n
163: << 1) + 1],&iwa[*n + 1]);
164: MINPACKseq(n,&indrow[1],&jpntr[1],&indcol[1],&ipntr[1],&iwa[(*n << 2) + 1],
165: &iwa[1],&numgrp,&iwa[*n + 1]);
167: /* Retain the best of the three orderings and exit. */
169: if (numgrp < *maxgrp) {
170: *maxgrp = numgrp;
171: i__1 = *n;
172: for (j = 1; j <= i__1; ++j) {
173: ngrp[j] = iwa[j];
174: }
175: }
176: return(0);
177: }