Actual source code: dsm.c
1: #define PETSCMAT_DLL
2: /* dsm.f -- translated by f2c (version of 25 March 1992 12:58:56). */
4: #include petsc.h
5: #include src/mat/color/color.h
7: static PetscInt c_n1 = -1;
11: PetscErrorCode MINPACKdsm(PetscInt *m,PetscInt *n,PetscInt *npairs,PetscInt *indrow,PetscInt *indcol,PetscInt *ngrp,PetscInt *maxgrp,
12: PetscInt *mingrp,PetscInt *info,PetscInt *ipntr,PetscInt *jpntr,PetscInt *iwa,PetscInt *liwa)
13: {
14: /* System generated locals */
15: PetscInt i__1,i__2,i__3;
17: /* Local variables */
18: PetscInt i,j,maxclq,numgrp;
20: /* Given the sparsity pattern of an m by n matrix A, this */
21: /* subroutine determines a partition of the columns of A */
22: /* consistent with the direct determination of A. */
23: /* The sparsity pattern of the matrix A is specified by */
24: /* the arrays indrow and indcol. On input the indices */
25: /* for the non-zero elements of A are */
26: /* indrow(k),indcol(k), k = 1,2,...,npairs. */
27: /* The (indrow,indcol) pairs may be specified in any order. */
28: /* Duplicate input pairs are permitted, but the subroutine */
29: /* eliminates them. */
30: /* The subroutine partitions the columns of A into groups */
31: /* such that columns in the same group do not have a */
32: /* non-zero in the same row position. A partition of the */
33: /* columns of A with this property is consistent with the */
34: /* direct determination of A. */
35: /* The subroutine statement is */
36: /* subroutine dsm(m,n,npairs,indrow,indcol,ngrp,maxgrp,mingrp, */
37: /* info,ipntr,jpntr,iwa,liwa) */
38: /* where */
39: /* m is a positive integer input variable set to the number */
40: /* of rows of A. */
41: /* n is a positive integer input variable set to the number */
42: /* of columns of A. */
43: /* npairs is a positive integer input variable set to the */
44: /* number of (indrow,indcol) pairs used to describe the */
45: /* sparsity pattern of A. */
46: /* indrow is an integer array of length npairs. On input indrow */
47: /* must contain the row indices of the non-zero elements of A. */
48: /* On output indrow is permuted so that the corresponding */
49: /* column indices are in non-decreasing order. The column */
50: /* indices can be recovered from the array jpntr. */
51: /* indcol is an integer array of length npairs. On input indcol */
52: /* must contain the column indices of the non-zero elements of */
53: /* A. On output indcol is permuted so that the corresponding */
54: /* row indices are in non-decreasing order. The row indices */
55: /* can be recovered from the array ipntr. */
56: /* ngrp is an integer output array of length n which specifies */
57: /* the partition of the columns of A. Column jcol belongs */
58: /* to group ngrp(jcol). */
59: /* maxgrp is an integer output variable which specifies the */
60: /* number of groups in the partition of the columns of A. */
61: /* mingrp is an integer output variable which specifies a lower */
62: /* bound for the number of groups in any consistent partition */
63: /* of the columns of A. */
64: /* info is an integer output variable set as follows. For */
65: /* normal termination info = 1. If m, n, or npairs is not */
66: /* positive or liwa is less than max(m,6*n), then info = 0. */
67: /* If the k-th element of indrow is not an integer between */
68: /* 1 and m or the k-th element of indcol is not an integer */
69: /* between 1 and n, then info = -k. */
70: /* ipntr is an integer output array of length m + 1 which */
71: /* specifies the locations of the column indices in indcol. */
72: /* The column indices for row i are */
73: /* indcol(k), k = ipntr(i),...,ipntr(i+1)-1. */
74: /* Note that ipntr(m+1)-1 is then the number of non-zero */
75: /* elements of the matrix A. */
76: /* jpntr is an integer output array of length n + 1 which */
77: /* specifies the locations of the row indices in indrow. */
78: /* The row indices for column j are */
79: /* indrow(k), k = jpntr(j),...,jpntr(j+1)-1. */
80: /* Note that jpntr(n+1)-1 is then the number of non-zero */
81: /* elements of the matrix A. */
82: /* iwa is an integer work array of length liwa. */
83: /* liwa is a positive integer input variable not less than */
84: /* max(m,6*n). */
85: /* Subprograms called */
86: /* MINPACK-supplied ... degr,ido,numsrt,seq,setr,slo,srtdat */
87: /* FORTRAN-supplied ... max */
88: /* Argonne National Laboratory. MINPACK Project. December 1984. */
89: /* Thomas F. Coleman, Burton S. Garbow, Jorge J. More' */
92: /* Parameter adjustments */
93: --iwa;
94: --jpntr;
95: --ipntr;
96: --ngrp;
97: --indcol;
98: --indrow;
100: *info = 0;
102: /* Determine a lower bound for the number of groups. */
104: *mingrp = 0;
105: i__1 = *m;
106: for (i = 1; i <= i__1; ++i) {
107: /* Computing MAX */
108: i__2 = *mingrp,i__3 = ipntr[i + 1] - ipntr[i];
109: *mingrp = PetscMax(i__2,i__3);
110: }
112: /* Determine the degree sequence for the intersection */
113: /* graph of the columns of A. */
115: MINPACKdegr(n,&indrow[1],&jpntr[1],&indcol[1],&ipntr[1],&iwa[*n * 5 + 1],&
116: iwa[*n + 1]);
118: /* Color the intersection graph of the columns of A */
119: /* with the smallest-last (SL) ordering. */
121: MINPACKslo(n,&indrow[1],&jpntr[1],&indcol[1],&ipntr[1],&iwa[*n * 5 + 1],&
122: iwa[(*n << 2) + 1],&maxclq,&iwa[1],&iwa[*n + 1],&iwa[(*n << 1)
123: + 1],&iwa[*n * 3 + 1]);
124: MINPACKseq(n,&indrow[1],&jpntr[1],&indcol[1],&ipntr[1],&iwa[(*n << 2) + 1],
125: &ngrp[1],maxgrp,&iwa[*n + 1]);
126: *mingrp = PetscMax(*mingrp,maxclq);
128: /* Exit if the smallest-last ordering is optimal. */
130: if (*maxgrp == *mingrp) {
131: return(0);
132: }
134: /* Color the intersection graph of the columns of A */
135: /* with the incidence-degree (ID) ordering. */
137: MINPACKido(m,n,&indrow[1],&jpntr[1],&indcol[1],&ipntr[1],&iwa[*n * 5 + 1],
138: &iwa[(*n << 2) + 1],&maxclq,&iwa[1],&iwa[*n + 1],&iwa[(*n <<
139: 1) + 1],&iwa[*n * 3 + 1]);
140: MINPACKseq(n,&indrow[1],&jpntr[1],&indcol[1],&ipntr[1],&iwa[(*n << 2) + 1],
141: &iwa[1],&numgrp,&iwa[*n + 1]);
142: *mingrp = PetscMax(*mingrp,maxclq);
144: /* Retain the better of the two orderings so far. */
146: if (numgrp < *maxgrp) {
147: *maxgrp = numgrp;
148: i__1 = *n;
149: for (j = 1; j <= i__1; ++j) {
150: ngrp[j] = iwa[j];
151: }
153: /* Exit if the incidence-degree ordering is optimal. */
155: if (*maxgrp == *mingrp) {
156: return(0);
157: }
158: }
160: /* Color the intersection graph of the columns of A */
161: /* with the largest-first (LF) ordering. */
163: i__1 = *n - 1;
164: MINPACKnumsrt(n,&i__1,&iwa[*n * 5 + 1],&c_n1,&iwa[(*n << 2) + 1],&iwa[(*n
165: << 1) + 1],&iwa[*n + 1]);
166: MINPACKseq(n,&indrow[1],&jpntr[1],&indcol[1],&ipntr[1],&iwa[(*n << 2) + 1],
167: &iwa[1],&numgrp,&iwa[*n + 1]);
169: /* Retain the best of the three orderings and exit. */
171: if (numgrp < *maxgrp) {
172: *maxgrp = numgrp;
173: i__1 = *n;
174: for (j = 1; j <= i__1; ++j) {
175: ngrp[j] = iwa[j];
176: }
177: }
178: return(0);
179: }