xref: /petsc/src/mat/utils/convert.c (revision bbb6d6a8ce168c53119d255f697846c361b726e4)
1 #ifndef lint
2 static char vcid[] = "$Id: convert.c,v 1.19 1995/06/08 03:10:22 bsmith Exp bsmith $";
3 #endif
4 
5 /* Matrix conversion routines.  For now, this supports only AIJ */
6 
7 #include "mpiaij.h"
8 #define  ABS(a) ((a > 0) ? a : -a)
9 
10 /* Determines the block diagonals within a subset of a matrix */
11 /* For now this is just sequential -- not parallel */
12 
13 /*
14    MatDetermineDiagonals_Private - Determines the diagonal structure
15    of a matrix.
16 
17    Input Parameters:
18 .  mat - the matrix
19 .  nb - block size
20 .  irows - rows to use
21 .  icols - columns to use
22 
23    Output Parameters:
24 .  ndiag - number of diagonals
25 .  diagonals - the diagonal numbers
26 
27    Note:  The user must free the diagonals array.
28  */
29 
30 int MatDetermineDiagonals_Private(Mat mat,int nb,int newr,int newc,
31             int *rowrange, int *colrange,int *ndiag, int **diagonals)
32 {
33   int    nd, clast, cfirst, ierr, nnc, maxd, nz, *col, *cwork, *diag;
34   int    i, j, k, jdiag, cshift, row, dnew, temp;
35   Scalar *v;
36 
37   VALIDHEADER(mat,MAT_COOKIE);
38   if ((newr%nb) || (newc%nb))
39     SETERRQ(1,"MatDetermineDiagonals_Private:Invalid block size");
40   cfirst = colrange[0];
41   clast  = colrange[newc-1];
42   nnc    = clast - cfirst + 1;
43   cwork  = (int *) PETSCMALLOC( nnc * sizeof(int) );	CHKPTRQ(cwork);
44   for (i=0; i<nnc; i++)  cwork[i] = -1;
45   for (i=0; i<newc; i++) cwork[colrange[i]-cfirst] = i;
46 
47   /* Determine which diagonals exist:  compute nd, diag[]: */
48   /* Temporarily ssume diag[0] = 0 (main diagonal) */
49   maxd = newr + newc - 1;	/* maximum possible diagonals */
50   diag = (int *)PETSCMALLOC( maxd * sizeof(int) );	CHKPTRQ(diag);
51   nd = 1;
52   for (i=0; i<maxd; i++) diag[i] = 0;
53   for (i=0; i<newr; i++) {
54     ierr = MatGetRow( mat, rowrange[i], &nz, &col, &v ); CHKERRQ(ierr);
55     row = i;
56     j   = 0;
57     /* Skip values until we reach the first column */
58     while (j < nz && col[j] < cfirst) j++;
59     while (j < nz) {
60       if (clast < col[j]) break;
61       cshift = cwork[col[j] - cfirst];
62       if (cshift >= 0) {
63         /* Determine if diagonal block already exits for valid colum */
64         dnew = 1;
65         jdiag = row/nb - cshift/nb;
66         for (k=0; k<nd; k++) {
67           if (diag[k] == jdiag) {	/* diagonal exists */
68             dnew = 0;	break;
69           }
70         }
71         if (dnew) {
72 	  diag[nd] = jdiag;
73 	  nd++;
74           if (ABS(jdiag) > newr/nb)
75              { printf("ERROR jdiag\n"); }
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_AIJ - Converts from MATAIJ format to another format. For
100   parallel formats, the new matrix distribution is determined by PETSc.
101  */
102 int MatConvert_AIJ(Mat mat, MatType newtype, Mat *newmat)
103 {
104   Mat_AIJ *aij = (Mat_AIJ *) 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 MATROW:
110       ierr = MatCreateSequentialRow(mat->comm,m,n,0,aij->ilen,newmat);
111       CHKERRQ(ierr); break;
112     case MATMPIROW:
113       ierr = MatCreateMPIRow(MPI_COMM_WORLD,PETSC_DECIDE,PETSC_DECIDE,
114              m,n,0,0,0,0,newmat); /* Could do smarter memory allocation */
115       CHKERRQ(ierr); break;
116     case MATMPIAIJ:
117       ierr = MatCreateMPIAIJ(MPI_COMM_WORLD,PETSC_DECIDE,PETSC_DECIDE,
118              m,n,0,0,0,0,newmat); /* Could do smarter memory allocation */
119       CHKERRQ(ierr); break;
120     case MATDENSE:
121       ierr = MatCreateSequentialDense(mat->comm,m,n,newmat);
122       CHKERRQ(ierr); break;
123     case MATBDIAG:
124     { int nb = 1; /* Default block size = 1 */
125       int ndiag, *diag, *rr, *cr;
126       rr = (int *) PETSCMALLOC( (m+n) * sizeof(int) ); CHKPTRQ(rr);
127       cr = rr + m;
128       for (i=0; i<m; i++) rr[i] = i;
129       for (i=0; i<n; i++) cr[i] = i;
130       OptionsGetInt(0,"-mat_bdiag_bsize",&nb);
131       ierr = MatDetermineDiagonals_Private(mat,nb,m,n,rr,cr,&ndiag,&diag);
132       CHKERRQ(ierr);
133       ierr = MatCreateSequentialBDiag(mat->comm,m,n,ndiag,nb,diag,0,newmat);
134       CHKERRQ(ierr);
135       PETSCFREE(rr), PETSCFREE(diag);
136       break;
137     }
138     case MATMPIBDIAG:
139     { int nb = 1; /* Default block size = 1 */
140       int ndiag, *diag, *rr, *cr;
141       rr = (int *) PETSCMALLOC( (m+n) * sizeof(int) ); CHKPTRQ(rr);
142       cr = rr + m;
143       for (i=0; i<m; i++) rr[i] = i;
144       for (i=0; i<n; i++) cr[i] = i;
145       OptionsGetInt(0,"-mat_bdiag_bsize",&nb);
146       ierr = MatDetermineDiagonals_Private(mat,nb,m,n,rr,cr,&ndiag,&diag);
147       CHKERRQ(ierr);
148       ierr = MatCreateMPIBDiag(MPI_COMM_WORLD,PETSC_DECIDE,m,n,ndiag,nb,
149              diag,0,newmat); CHKERRQ(ierr);
150       PETSCFREE(rr), PETSCFREE(diag);
151       CHKERRQ(ierr); break;
152     }
153     default:
154       SETERRQ(1,"MatConvert_AIJ:Matrix type is not currently supported");
155   }
156   ierr = MatGetOwnershipRange(*newmat,&rstart,&rend); CHKERRQ(ierr);
157   for (i=rstart; i<rend; i++) {
158     ierr = MatGetRow(mat,i,&nz,&cwork,&vwork); CHKERRQ(ierr);
159     ierr = MatSetValues(*newmat,1,&i,nz,cwork,vwork,INSERTVALUES);
160            CHKERRQ(ierr);
161     ierr = MatRestoreRow(mat,i,&nz,&cwork,&vwork); CHKERRQ(ierr);
162   }
163   ierr = MatAssemblyBegin(*newmat,FINAL_ASSEMBLY); CHKERRQ(ierr);
164   ierr = MatAssemblyEnd(*newmat,FINAL_ASSEMBLY); CHKERRQ(ierr);
165   return 0;
166 }
167 /* ------------------------------------------------------------------ */
168 /*
169   MatConvert_MPIAIJ - Converts from MATMPIAIJ format to another
170   parallel format.
171  */
172 int MatConvert_MPIAIJ(Mat mat, MatType newtype, Mat *newmat)
173 {
174   Mat_MPIAIJ *aij = (Mat_MPIAIJ *) mat->data;
175   Mat_AIJ    *Ad = (Mat_AIJ *)(aij->A->data), *Bd = (Mat_AIJ *)(aij->B->data);
176   int        ierr, nz, i, ig,rstart = aij->rstart, m = aij->m, *cwork;
177   Scalar     *vwork;
178 
179   switch (newtype) {
180     case MATMPIROW:
181       for (i=0; i<m; i++)
182         {ierr = MatCreateMPIRow(mat->comm,m,aij->n,aij->M,aij->N,0,Ad->ilen,
183 			0,Bd->ilen,newmat); CHKERRQ(ierr); }
184       break;
185     default:
186       SETERRQ(1,"MatConvert_MPIAIJ:Only MATMPIROW is currently suported");
187   }
188   /* Each processor converts its local rows */
189   for (i=0; i<m; i++) {
190     ig   = i + rstart;
191     ierr = MatGetRow(mat,ig,&nz,&cwork,&vwork);	CHKERRQ(ierr);
192     ierr = MatSetValues(*newmat,1,&ig,nz,cwork,vwork,
193 		INSERTVALUES); 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