xref: /petsc/src/mat/utils/convert.c (revision 416022c9818a71eecdf06d41c1abd586feaab60e)
1 #ifndef lint
2 static char vcid[] = "$Id: convert.c,v 1.26 1995/09/21 20:11:31 bsmith Exp bsmith $";
3 #endif
4 
5 /* Matrix conversion routines.  For now, this supports only AIJ */
6 
7 #include "mpiaij.h"
8 
9 /* Determines the block diagonals within a subset of a matrix */
10 /* For now this is just sequential -- not parallel */
11 
12 /*
13    MatDetermineDiagonals_Private - Determines the diagonal structure
14    of a matrix.
15 
16    Input Parameters:
17 .  mat - the matrix
18 .  nb - block size
19 .  irows - rows to use
20 .  icols - columns to use
21 
22    Output Parameters:
23 .  ndiag - number of diagonals
24 .  diagonals - the diagonal numbers
25 
26    Note:  The user must free the diagonals array.
27  */
28 
29 int MatDetermineDiagonals_Private(Mat mat,int nb,int newr,int newc,int *rowrange,
30                                   int *colrange,int *ndiag, int **diagonals)
31 {
32   int    nd, clast, cfirst, ierr, nnc, maxd, nz, *col, *cwork, *diag;
33   int    i, j, k, jdiag, cshift, row, dnew, temp;
34   Scalar *v;
35 
36   PETSCVALIDHEADERSPECIFIC(mat,MAT_COOKIE);
37   if ((newr%nb)||(newc%nb)) SETERRQ(1,"MatDetermineDiagonals_Private:Bad block size");
38   cfirst = colrange[0];
39   clast  = colrange[newc-1];
40   nnc    = clast - cfirst + 1;
41   cwork  = (int *) PETSCMALLOC( nnc * sizeof(int) );	CHKPTRQ(cwork);
42   for (i=0; i<nnc; i++)  cwork[i] = -1;
43   for (i=0; i<newc; i++) cwork[colrange[i]-cfirst] = i;
44 
45   /* Determine which diagonals exist:  compute nd, diag[]: */
46   /* Temporarily ssume diag[0] = 0 (main diagonal) */
47   maxd = newr + newc - 1;	/* maximum possible diagonals */
48   diag = (int *)PETSCMALLOC( maxd * sizeof(int) );	CHKPTRQ(diag);
49   nd = 1;
50   for (i=0; i<maxd; i++) diag[i] = 0;
51   for (i=0; i<newr; i++) {
52     ierr = MatGetRow( mat, rowrange[i], &nz, &col, &v ); CHKERRQ(ierr);
53     row = i;
54     j   = 0;
55     /* Skip values until we reach the first column */
56     while (j < nz && col[j] < cfirst) j++;
57     while (j < nz) {
58       if (clast < col[j]) break;
59       cshift = cwork[col[j] - cfirst];
60       if (cshift >= 0) {
61         /* Determine if diagonal block already exits for valid colum */
62         dnew = 1;
63         jdiag = row/nb - cshift/nb;
64         for (k=0; k<nd; k++) {
65           if (diag[k] == jdiag) {	/* diagonal exists */
66             dnew = 0;	break;
67           }
68         }
69         if (dnew) {
70 	  diag[nd] = jdiag;
71 	  nd++;
72           /* what the hell is this? Not good PETSc style */
73           if (PETSCABS(jdiag) > newr/nb) {
74             SETERRQ(1," MatDetermineDiagonals_Private: bad jdiag");
75           }
76         }
77       }
78       j++;
79     }
80     ierr = MatRestoreRow( mat, rowrange[i], &nz, &col, &v ); CHKERRQ(ierr);
81   }
82   /* Sort diagonals in decreasing order. */
83   for (k=0; k<nd; k++) {
84     for (j=k+1; j<nd; j++) {
85       if (diag[k] < diag[j]) {
86         temp = diag[k];
87         diag[k] = diag[j];
88         diag[j] = temp;
89       }
90     }
91   }
92   PETSCFREE( cwork );
93   *ndiag = nd;
94   *diagonals = diag;
95   return 0;
96 }
97 
98 /*
99   MatConvert_SeqAIJ - Converts from MATSEQAIJ format to another format. For
100   parallel formats, the new matrix distribution is determined by PETSc.
101  */
102 int MatConvert_SeqAIJ(Mat mat, MatType newtype, Mat *newmat)
103 {
104   Mat_SeqAIJ *aij = (Mat_SeqAIJ *) mat->data;
105   Scalar     *vwork;
106   int        i, ierr, nz, m = aij->m, n = aij->n, *cwork, rstart, rend;
107 
108   switch (newtype) {
109     case MATSEQROW:
110       ierr = MatCreateSeqRow(mat->comm,m,n,0,aij->ilen,newmat);CHKERRQ(ierr);
111       break;
112     case MATMPIROW:
113       if (m != n) SETERRQ(1,"MatConvert_SeqAIJ: MPIRowbs matrix must be square");
114       ierr = MatCreateMPIRow(MPI_COMM_WORLD,PETSC_DECIDE,PETSC_DECIDE,
115                              m,n,0,0,0,0,newmat); CHKERRQ(ierr);
116       break;
117     case MATMPIROWBS:
118       ierr = MatCreateMPIRowbs(MPI_COMM_WORLD,PETSC_DECIDE,
119                                m,0,0,0,newmat);CHKERRQ(ierr);
120       break;
121     case MATMPIAIJ:
122       ierr = MatCreateMPIAIJ(MPI_COMM_WORLD,PETSC_DECIDE,PETSC_DECIDE,
123                              m,n,0,0,0,0,newmat);CHKERRQ(ierr);
124       break;
125     case MATSEQDENSE:
126       ierr = MatCreateSeqDense(mat->comm,m,n,newmat); CHKERRQ(ierr);
127       break;
128     case MATSEQBDIAG:
129       {
130       int nb = 1, /* Default block size = 1 */ ndiag, *diag, *rr, *cr;
131       rr = (int *) PETSCMALLOC( (m+n) * sizeof(int) ); CHKPTRQ(rr);
132       cr = rr + m;
133       for (i=0; i<m; i++) rr[i] = i;
134       for (i=0; i<n; i++) cr[i] = i;
135       OptionsGetInt(0,"-mat_bdiag_bsize",&nb);
136       ierr = MatDetermineDiagonals_Private(mat,nb,m,n,rr,cr,&ndiag,&diag);CHKERRQ(ierr);
137       ierr = MatCreateSeqBDiag(mat->comm,m,n,ndiag,nb,diag,0,newmat); CHKERRQ(ierr);
138       PETSCFREE(rr), PETSCFREE(diag);
139       break;
140       }
141     case MATMPIBDIAG:
142       {
143       int nb = 1, /* Default block size = 1 */ ndiag, *diag, *rr, *cr;
144       rr = (int *) PETSCMALLOC( (m+n) * sizeof(int) ); CHKPTRQ(rr);
145       cr = rr + m;
146       for (i=0; i<m; i++) rr[i] = i;
147       for (i=0; i<n; i++) cr[i] = i;
148       OptionsGetInt(0,"-mat_bdiag_bsize",&nb);
149       ierr = MatDetermineDiagonals_Private(mat,nb,m,n,rr,cr,&ndiag,&diag);
150       CHKERRQ(ierr);
151       ierr = MatCreateMPIBDiag(MPI_COMM_WORLD,PETSC_DECIDE,m,n,ndiag,nb,
152                                diag,0,newmat); CHKERRQ(ierr);
153       PETSCFREE(rr), PETSCFREE(diag);
154       break;
155       }
156     default:
157       SETERRQ(1,"MatConvert_SeqAIJ:Matrix type is not currently supported");
158   }
159   ierr = MatGetOwnershipRange(*newmat,&rstart,&rend); CHKERRQ(ierr);
160   for (i=rstart; i<rend; i++) {
161     ierr = MatGetRow(mat,i,&nz,&cwork,&vwork); CHKERRQ(ierr);
162     ierr = MatSetValues(*newmat,1,&i,nz,cwork,vwork,INSERT_VALUES); CHKERRQ(ierr);
163     ierr = MatRestoreRow(mat,i,&nz,&cwork,&vwork); CHKERRQ(ierr);
164   }
165   ierr = MatAssemblyBegin(*newmat,FINAL_ASSEMBLY); CHKERRQ(ierr);
166   ierr = MatAssemblyEnd(*newmat,FINAL_ASSEMBLY); CHKERRQ(ierr);
167   return 0;
168 }
169 /* ------------------------------------------------------------------ */
170 /*
171   MatConvert_MPIAIJ - Converts from MATMPIAIJ format to another
172   parallel format.
173  */
174 int MatConvert_MPIAIJ(Mat mat, MatType newtype, Mat *newmat)
175 {
176   Mat_MPIAIJ *aij = (Mat_MPIAIJ *) mat->data;
177   Mat_SeqAIJ *Ad = (Mat_SeqAIJ *)(aij->A->data), *Bd = (Mat_SeqAIJ *)(aij->B->data);
178   int        ierr, nz, i, ig,rstart = aij->rstart, m = aij->m, *cwork;
179   Scalar     *vwork;
180 
181   switch (newtype) {
182     case MATMPIROW:
183       ierr = MatCreateMPIRow(mat->comm,m,aij->n,aij->M,aij->N,0,Ad->ilen,
184 			0,Bd->ilen,newmat); CHKERRQ(ierr);
185       break;
186     default:
187       SETERRQ(1,"MatConvert_MPIAIJ:Only MATMPIROW is currently suported");
188   }
189   /* Each processor converts its local rows */
190   for (i=0; i<m; i++) {
191     ig   = i + rstart;
192     ierr = MatGetRow(mat,ig,&nz,&cwork,&vwork);	CHKERRQ(ierr);
193     ierr = MatSetValues(*newmat,1,&ig,nz,cwork,vwork,INSERT_VALUES); CHKERRQ(ierr);
194     ierr = MatRestoreRow(mat,ig,&nz,&cwork,&vwork); CHKERRQ(ierr);
195   }
196   ierr = MatAssemblyBegin(*newmat,FINAL_ASSEMBLY); CHKERRQ(ierr);
197   ierr = MatAssemblyEnd(*newmat,FINAL_ASSEMBLY); CHKERRQ(ierr);
198   return 0;
199 }
200 
201 
202