Actual source code: mmaij.c

  1: /*$Id: mmaij.c,v 1.59 2001/08/07 03:02:49 balay Exp $*/

  3: /*
  4:    Support for the parallel AIJ matrix vector multiply
  5: */
 6:  #include src/mat/impls/aij/mpi/mpiaij.h
 7:  #include src/vec/vecimpl.h

  9: int MatSetUpMultiply_MPIAIJ(Mat mat)
 10: {
 11:   Mat_MPIAIJ         *aij = (Mat_MPIAIJ*)mat->data;
 12:   Mat_SeqAIJ         *B = (Mat_SeqAIJ*)(aij->B->data);
 13:   int                N = mat->N,i,j,*indices,*aj = B->j,ierr,ec = 0,*garray;
 14:   int                shift = B->indexshift;
 15:   IS                 from,to;
 16:   Vec                gvec;
 17: #if defined (PETSC_USE_CTABLE)
 18:   PetscTable         gid1_lid1;
 19:   PetscTablePosition tpos;
 20:   int                gid,lid;
 21: #endif


 25: #if defined (PETSC_USE_CTABLE)
 26:   /* use a table - Mark Adams (this has not been tested with "shift") */
 27:   PetscTableCreate(aij->B->m,&gid1_lid1);
 28:   for (i=0; i<aij->B->m; i++) {
 29:     for (j=0; j<B->ilen[i]; j++) {
 30:       int data,gid1 = aj[B->i[i] + shift + j] + 1 + shift;
 31:       PetscTableFind(gid1_lid1,gid1,&data);
 32:       if (!data) {
 33:         /* one based table */
 34:         PetscTableAdd(gid1_lid1,gid1,++ec);
 35:       }
 36:     }
 37:   }
 38:   /* form array of columns we need */
 39:   PetscMalloc((ec+1)*sizeof(int),&garray);
 40:   PetscTableGetHeadPosition(gid1_lid1,&tpos);
 41:   while (tpos) {
 42:     PetscTableGetNext(gid1_lid1,&tpos,&gid,&lid);
 43:     gid--;
 44:     lid--;
 45:     garray[lid] = gid;
 46:   }
 47:   PetscSortInt(ec,garray); /* sort, and rebuild */
 48:   PetscTableRemoveAll(gid1_lid1);
 49:   for (i=0; i<ec; i++) {
 50:     PetscTableAdd(gid1_lid1,garray[i]+1,i+1);
 51:   }
 52:   /* compact out the extra columns in B */
 53:   for (i=0; i<aij->B->m; i++) {
 54:     for (j=0; j<B->ilen[i]; j++) {
 55:       int gid1 = aj[B->i[i] + shift + j] + 1 + shift;
 56:       PetscTableFind(gid1_lid1,gid1,&lid);
 57:       lid --;
 58:       aj[B->i[i] + shift + j]  = lid - shift;
 59:     }
 60:   }
 61:   aij->B->n = aij->B->N = ec;
 62:   PetscTableDelete(gid1_lid1);
 63:   /* Mark Adams */
 64: #else
 65:   /* For the first stab we make an array as long as the number of columns */
 66:   /* mark those columns that are in aij->B */
 67:   PetscMalloc((N+1)*sizeof(int),&indices);
 68:   PetscMemzero(indices,N*sizeof(int));
 69:   for (i=0; i<aij->B->m; i++) {
 70:     for (j=0; j<B->ilen[i]; j++) {
 71:       if (!indices[aj[B->i[i] +shift + j] + shift]) ec++;
 72:       indices[aj[B->i[i] + shift + j] + shift] = 1;
 73:     }
 74:   }

 76:   /* form array of columns we need */
 77:   PetscMalloc((ec+1)*sizeof(int),&garray);
 78:   ec = 0;
 79:   for (i=0; i<N; i++) {
 80:     if (indices[i]) garray[ec++] = i;
 81:   }

 83:   /* make indices now point into garray */
 84:   for (i=0; i<ec; i++) {
 85:     indices[garray[i]] = i-shift;
 86:   }

 88:   /* compact out the extra columns in B */
 89:   for (i=0; i<aij->B->m; i++) {
 90:     for (j=0; j<B->ilen[i]; j++) {
 91:       aj[B->i[i] + shift + j] = indices[aj[B->i[i] + shift + j]+shift];
 92:     }
 93:   }
 94:   aij->B->n = aij->B->N = ec;
 95:   PetscFree(indices);
 96: #endif  
 97:   /* create local vector that is used to scatter into */
 98:   VecCreateSeq(PETSC_COMM_SELF,ec,&aij->lvec);

100:   /* create two temporary Index sets for build scatter gather */
101:   ISCreateGeneral(mat->comm,ec,garray,&from);
102:   ISCreateStride(PETSC_COMM_SELF,ec,0,1,&to);

104:   /* create temporary global vector to generate scatter context */
105:   /* this is inefficient, but otherwise we must do either 
106:      1) save garray until the first actual scatter when the vector is known or
107:      2) have another way of generating a scatter context without a vector.*/
108:   VecCreateMPI(mat->comm,mat->n,mat->N,&gvec);

110:   /* generate the scatter context */
111:   VecScatterCreate(gvec,from,aij->lvec,to,&aij->Mvctx);
112:   PetscLogObjectParent(mat,aij->Mvctx);
113:   PetscLogObjectParent(mat,aij->lvec);
114:   PetscLogObjectParent(mat,from);
115:   PetscLogObjectParent(mat,to);
116:   aij->garray = garray;
117:   PetscLogObjectMemory(mat,(ec+1)*sizeof(int));
118:   ISDestroy(from);
119:   ISDestroy(to);
120:   VecDestroy(gvec);
121:   return(0);
122: }


125: /*
126:      Takes the local part of an already assembled MPIAIJ matrix
127:    and disassembles it. This is to allow new nonzeros into the matrix
128:    that require more communication in the matrix vector multiply. 
129:    Thus certain data-structures must be rebuilt.

131:    Kind of slow! But that's what application programmers get when 
132:    they are sloppy.
133: */
134: int DisAssemble_MPIAIJ(Mat A)
135: {
136:   Mat_MPIAIJ   *aij = (Mat_MPIAIJ*)A->data;
137:   Mat          B = aij->B,Bnew;
138:   Mat_SeqAIJ   *Baij = (Mat_SeqAIJ*)B->data;
139:   int          ierr,i,j,m = B->m,n = A->N,col,ct = 0,*garray = aij->garray;
140:   int          *nz,ec,shift = Baij->indexshift;
141:   PetscScalar  v;

144:   /* free stuff related to matrix-vec multiply */
145:   VecGetSize(aij->lvec,&ec); /* needed for PetscLogObjectMemory below */
146:   VecDestroy(aij->lvec); aij->lvec = 0;
147:   VecScatterDestroy(aij->Mvctx); aij->Mvctx = 0;
148:   if (aij->colmap) {
149: #if defined (PETSC_USE_CTABLE)
150:     PetscTableDelete(aij->colmap);
151:     aij->colmap = 0;
152: #else
153:     PetscFree(aij->colmap);
154:     aij->colmap = 0;
155:     PetscLogObjectMemory(A,-aij->B->n*sizeof(int));
156: #endif
157:   }

159:   /* make sure that B is assembled so we can access its values */
160:   MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);
161:   MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);

163:   /* invent new B and copy stuff over */
164:   PetscMalloc((m+1)*sizeof(int),&nz);
165:   for (i=0; i<m; i++) {
166:     nz[i] = Baij->i[i+1] - Baij->i[i];
167:   }
168:   MatCreateSeqAIJ(PETSC_COMM_SELF,m,n,0,nz,&Bnew);
169:   PetscFree(nz);
170:   for (i=0; i<m; i++) {
171:     for (j=Baij->i[i]+shift; j<Baij->i[i+1]+shift; j++) {
172:       col  = garray[Baij->j[ct]+shift];
173:       v    = Baij->a[ct++];
174:       MatSetValues(Bnew,1,&i,1,&col,&v,B->insertmode);
175:     }
176:   }
177:   PetscFree(aij->garray);
178:   aij->garray = 0;
179:   PetscLogObjectMemory(A,-ec*sizeof(int));
180:   MatDestroy(B);
181:   PetscLogObjectParent(A,Bnew);
182:   aij->B = Bnew;
183:   A->was_assembled = PETSC_FALSE;
184:   return(0);
185: }

187: /*      ugly stuff added for Glenn someday we should fix this up */

189: static int *auglyrmapd = 0,*auglyrmapo = 0;  /* mapping from the local ordering to the "diagonal" and "off-diagonal"
190:                                       parts of the local matrix */
191: static Vec auglydd = 0,auglyoo = 0;   /* work vectors used to scale the two parts of the local matrix */


194: int MatMPIAIJDiagonalScaleLocalSetUp(Mat inA,Vec scale)
195: {
196:   Mat_MPIAIJ  *ina = (Mat_MPIAIJ*) inA->data; /*access private part of matrix */
197:   int          ierr,i,n,nt,cstart,cend,no,*garray = ina->garray,*lindices;
198:   int          *r_rmapd,*r_rmapo;
199: 
201:   MatGetOwnershipRange(inA,&cstart,&cend);
202:   MatGetSize(ina->A,PETSC_NULL,&n);
203:   PetscMalloc((inA->mapping->n+1)*sizeof(int),&r_rmapd);
204:   PetscMemzero(r_rmapd,inA->mapping->n*sizeof(int));
205:   nt   = 0;
206:   for (i=0; i<inA->mapping->n; i++) {
207:     if (inA->mapping->indices[i] >= cstart && inA->mapping->indices[i] < cend) {
208:       nt++;
209:       r_rmapd[i] = inA->mapping->indices[i] + 1;
210:     }
211:   }
212:   if (nt != n) SETERRQ2(1,"Hmm nt %d n %d",nt,n);
213:   PetscMalloc((n+1)*sizeof(int),&auglyrmapd);
214:   for (i=0; i<inA->mapping->n; i++) {
215:     if (r_rmapd[i]){
216:       auglyrmapd[(r_rmapd[i]-1)-cstart] = i;
217:     }
218:   }
219:   PetscFree(r_rmapd);
220:   VecCreateSeq(PETSC_COMM_SELF,n,&auglydd);

222:   PetscMalloc((inA->N+1)*sizeof(int),&lindices);
223:   PetscMemzero(lindices,inA->N*sizeof(int));
224:   for (i=0; i<ina->B->n; i++) {
225:     lindices[garray[i]] = i+1;
226:   }
227:   no   = inA->mapping->n - nt;
228:   PetscMalloc((inA->mapping->n+1)*sizeof(int),&r_rmapo);
229:   PetscMemzero(r_rmapo,inA->mapping->n*sizeof(int));
230:   nt   = 0;
231:   for (i=0; i<inA->mapping->n; i++) {
232:     if (lindices[inA->mapping->indices[i]]) {
233:       nt++;
234:       r_rmapo[i] = lindices[inA->mapping->indices[i]];
235:     }
236:   }
237:   if (nt > no) SETERRQ2(1,"Hmm nt %d no %d",nt,n);
238:   PetscFree(lindices);
239:   PetscMalloc((nt+1)*sizeof(int),&auglyrmapo);
240:   for (i=0; i<inA->mapping->n; i++) {
241:     if (r_rmapo[i]){
242:       auglyrmapo[(r_rmapo[i]-1)] = i;
243:     }
244:   }
245:   PetscFree(r_rmapo);
246:   VecCreateSeq(PETSC_COMM_SELF,nt,&auglyoo);

248:   return(0);
249: }

251: int MatMPIAIJDiagonalScaleLocal(Mat A,Vec scale)
252: {
253:   Mat_MPIAIJ  *a = (Mat_MPIAIJ*) A->data; /*access private part of matrix */
254:   int         ierr,n,i;
255:   PetscScalar *d,*o,*s;
256: 
258:   if (!auglyrmapd) {
259:     MatMPIAIJDiagonalScaleLocalSetUp(A,scale);
260:   }

262:   VecGetArray(scale,&s);
263: 
264:   VecGetLocalSize(auglydd,&n);
265:   VecGetArray(auglydd,&d);
266:   for (i=0; i<n; i++) {
267:     d[i] = s[auglyrmapd[i]]; /* copy "diagonal" (true local) portion of scale into dd vector */
268:   }
269:   VecRestoreArray(auglydd,&d);
270:   /* column scale "diagonal" portion of local matrix */
271:   MatDiagonalScale(a->A,PETSC_NULL,auglydd);

273:   VecGetLocalSize(auglyoo,&n);
274:   VecGetArray(auglyoo,&o);
275:   for (i=0; i<n; i++) {
276:     o[i] = s[auglyrmapo[i]]; /* copy "off-diagonal" portion of scale into oo vector */
277:   }
278:   VecRestoreArray(scale,&s);
279:   VecRestoreArray(auglyoo,&o);
280:   /* column scale "off-diagonal" portion of local matrix */
281:   MatDiagonalScale(a->B,PETSC_NULL,auglyoo);

283:   return(0);
284: }