xref: /petsc/src/mat/utils/convert.c (revision 1a9411475029bd0c092ff088e6540bae5153ea53)
1 #ifndef lint
2 static char vcid[] = "$Id: convert.c,v 1.21 1995/07/28 04:22:53 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,
30             int *rowrange, 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))
38     SETERRQ(1,"MatDetermineDiagonals_Private:Invalid block size");
39   cfirst = colrange[0];
40   clast  = colrange[newc-1];
41   nnc    = clast - cfirst + 1;
42   cwork  = (int *) PETSCMALLOC( nnc * sizeof(int) );	CHKPTRQ(cwork);
43   for (i=0; i<nnc; i++)  cwork[i] = -1;
44   for (i=0; i<newc; i++) cwork[colrange[i]-cfirst] = i;
45 
46   /* Determine which diagonals exist:  compute nd, diag[]: */
47   /* Temporarily ssume diag[0] = 0 (main diagonal) */
48   maxd = newr + newc - 1;	/* maximum possible diagonals */
49   diag = (int *)PETSCMALLOC( maxd * sizeof(int) );	CHKPTRQ(diag);
50   nd = 1;
51   for (i=0; i<maxd; i++) diag[i] = 0;
52   for (i=0; i<newr; i++) {
53     ierr = MatGetRow( mat, rowrange[i], &nz, &col, &v ); CHKERRQ(ierr);
54     row = i;
55     j   = 0;
56     /* Skip values until we reach the first column */
57     while (j < nz && col[j] < cfirst) j++;
58     while (j < nz) {
59       if (clast < col[j]) break;
60       cshift = cwork[col[j] - cfirst];
61       if (cshift >= 0) {
62         /* Determine if diagonal block already exits for valid colum */
63         dnew = 1;
64         jdiag = row/nb - cshift/nb;
65         for (k=0; k<nd; k++) {
66           if (diag[k] == jdiag) {	/* diagonal exists */
67             dnew = 0;	break;
68           }
69         }
70         if (dnew) {
71 	  diag[nd] = jdiag;
72 	  nd++;
73           if (PETSCABS(jdiag) > newr/nb)
74              { printf("ERROR jdiag\n"); }
75         }
76       }
77       j++;
78     }
79     ierr = MatRestoreRow( mat, rowrange[i], &nz, &col, &v ); CHKERRQ(ierr);
80   }
81   /* Sort diagonals in decreasing order. */
82   for (k=0; k<nd; k++) {
83     for (j=k+1; j<nd; j++) {
84       if (diag[k] < diag[j]) {
85         temp = diag[k];
86         diag[k] = diag[j];
87         diag[j] = temp;
88       }
89     }
90   }
91   PETSCFREE( cwork );
92   *ndiag = nd;
93   *diagonals = diag;
94   return 0;
95 }
96 
97 /*
98   MatConvert_AIJ - Converts from MATAIJ format to another format. For
99   parallel formats, the new matrix distribution is determined by PETSc.
100  */
101 int MatConvert_AIJ(Mat mat, MatType newtype, Mat *newmat)
102 {
103   Mat_AIJ *aij = (Mat_AIJ *) mat->data;
104   Scalar  *vwork;
105   int     i, ierr, nz, m = aij->m, n = aij->n, *cwork, rstart, rend;
106 
107   switch (newtype) {
108     case MATROW:
109       ierr = MatCreateSequentialRow(mat->comm,m,n,0,aij->ilen,newmat);
110       CHKERRQ(ierr); break;
111     case MATMPIROW:
112       ierr = MatCreateMPIRow(MPI_COMM_WORLD,PETSC_DECIDE,PETSC_DECIDE,
113              m,n,0,0,0,0,newmat); /* Could do smarter memory allocation */
114       CHKERRQ(ierr); break;
115     case MATMPIAIJ:
116       ierr = MatCreateMPIAIJ(MPI_COMM_WORLD,PETSC_DECIDE,PETSC_DECIDE,
117              m,n,0,0,0,0,newmat); /* Could do smarter memory allocation */
118       CHKERRQ(ierr); break;
119     case MATDENSE:
120       ierr = MatCreateSequentialDense(mat->comm,m,n,newmat);
121       CHKERRQ(ierr); break;
122     case MATBDIAG:
123     { int nb = 1; /* Default block size = 1 */
124       int ndiag, *diag, *rr, *cr;
125       rr = (int *) PETSCMALLOC( (m+n) * sizeof(int) ); CHKPTRQ(rr);
126       cr = rr + m;
127       for (i=0; i<m; i++) rr[i] = i;
128       for (i=0; i<n; i++) cr[i] = i;
129       OptionsGetInt(0,"-mat_bdiag_bsize",&nb);
130       ierr = MatDetermineDiagonals_Private(mat,nb,m,n,rr,cr,&ndiag,&diag);
131       CHKERRQ(ierr);
132       ierr = MatCreateSequentialBDiag(mat->comm,m,n,ndiag,nb,diag,0,newmat);
133       CHKERRQ(ierr);
134       PETSCFREE(rr), PETSCFREE(diag);
135       break;
136     }
137     case MATMPIBDIAG:
138     { int nb = 1; /* Default block size = 1 */
139       int ndiag, *diag, *rr, *cr;
140       rr = (int *) PETSCMALLOC( (m+n) * sizeof(int) ); CHKPTRQ(rr);
141       cr = rr + m;
142       for (i=0; i<m; i++) rr[i] = i;
143       for (i=0; i<n; i++) cr[i] = i;
144       OptionsGetInt(0,"-mat_bdiag_bsize",&nb);
145       ierr = MatDetermineDiagonals_Private(mat,nb,m,n,rr,cr,&ndiag,&diag);
146       CHKERRQ(ierr);
147       ierr = MatCreateMPIBDiag(MPI_COMM_WORLD,PETSC_DECIDE,m,n,ndiag,nb,
148              diag,0,newmat); CHKERRQ(ierr);
149       PETSCFREE(rr), PETSCFREE(diag);
150       CHKERRQ(ierr); break;
151     }
152     default:
153       SETERRQ(1,"MatConvert_AIJ:Matrix type is not currently supported");
154   }
155   ierr = MatGetOwnershipRange(*newmat,&rstart,&rend); CHKERRQ(ierr);
156   for (i=rstart; i<rend; i++) {
157     ierr = MatGetRow(mat,i,&nz,&cwork,&vwork); CHKERRQ(ierr);
158     ierr = MatSetValues(*newmat,1,&i,nz,cwork,vwork,INSERTVALUES);
159            CHKERRQ(ierr);
160     ierr = MatRestoreRow(mat,i,&nz,&cwork,&vwork); CHKERRQ(ierr);
161   }
162   ierr = MatAssemblyBegin(*newmat,FINAL_ASSEMBLY); CHKERRQ(ierr);
163   ierr = MatAssemblyEnd(*newmat,FINAL_ASSEMBLY); CHKERRQ(ierr);
164   return 0;
165 }
166 /* ------------------------------------------------------------------ */
167 /*
168   MatConvert_MPIAIJ - Converts from MATMPIAIJ format to another
169   parallel format.
170  */
171 int MatConvert_MPIAIJ(Mat mat, MatType newtype, Mat *newmat)
172 {
173   Mat_MPIAIJ *aij = (Mat_MPIAIJ *) mat->data;
174   Mat_AIJ    *Ad = (Mat_AIJ *)(aij->A->data), *Bd = (Mat_AIJ *)(aij->B->data);
175   int        ierr, nz, i, ig,rstart = aij->rstart, m = aij->m, *cwork;
176   Scalar     *vwork;
177 
178   switch (newtype) {
179     case MATMPIROW:
180       for (i=0; i<m; i++)
181         {ierr = MatCreateMPIRow(mat->comm,m,aij->n,aij->M,aij->N,0,Ad->ilen,
182 			0,Bd->ilen,newmat); CHKERRQ(ierr); }
183       break;
184     default:
185       SETERRQ(1,"MatConvert_MPIAIJ:Only MATMPIROW is currently suported");
186   }
187   /* Each processor converts its local rows */
188   for (i=0; i<m; i++) {
189     ig   = i + rstart;
190     ierr = MatGetRow(mat,ig,&nz,&cwork,&vwork);	CHKERRQ(ierr);
191     ierr = MatSetValues(*newmat,1,&ig,nz,cwork,vwork,
192 		INSERTVALUES); CHKERRQ(ierr);
193     ierr = MatRestoreRow(mat,ig,&nz,&cwork,&vwork); CHKERRQ(ierr);
194   }
195   ierr = MatAssemblyBegin(*newmat,FINAL_ASSEMBLY); CHKERRQ(ierr);
196   ierr = MatAssemblyEnd(*newmat,FINAL_ASSEMBLY); CHKERRQ(ierr);
197   return 0;
198 }
199