xref: /petsc/src/mat/impls/aij/seq/fdaij.c (revision b0a32e0c6855ee6a6cd3495fa7da12ea9885bc5d)
1 /*$Id: fdaij.c,v 1.35 2000/10/24 20:25:32 bsmith Exp bsmith $*/
2 
3 #include "src/mat/impls/aij/seq/aij.h"
4 #include "src/vec/vecimpl.h"
5 
6 EXTERN int MatGetColumnIJ_SeqAIJ(Mat,int,PetscTruth,int*,int**,int**,PetscTruth*);
7 EXTERN int MatRestoreColumnIJ_SeqAIJ(Mat,int,PetscTruth,int*,int**,int**,PetscTruth*);
8 
9 #undef __FUNC__
10 #define __FUNC__ "MatFDColoringCreate_SeqAIJ"
11 int MatFDColoringCreate_SeqAIJ(Mat mat,ISColoring iscoloring,MatFDColoring c)
12 {
13   int        i,*is,n,nrows,N = mat->N,j,k,m,*rows,ierr,*ci,*cj,ncols,col;
14   int        nis = iscoloring->n,*rowhit,*columnsforrow,l;
15   IS         *isa = iscoloring->is;
16   PetscTruth done,flg;
17 
18   PetscFunctionBegin;
19   if (!mat->assembled) {
20     SETERRQ(PETSC_ERR_ARG_WRONGSTATE,"Matrix must be assembled by calls to MatAssemblyBegin/End();");
21   }
22 
23   c->M       = mat->M;  /* set total rows, columns and local rows */
24   c->N       = mat->N;
25   c->m       = mat->M;
26   c->rstart  = 0;
27 
28   c->ncolors = nis;
29   ierr       = PetscMalloc(nis*sizeof(int),&c->ncolumns);CHKERRQ(ierr);
30   ierr       = PetscMalloc(nis*sizeof(int*),&c->columns);CHKERRQ(ierr);
31   ierr       = PetscMalloc(nis*sizeof(int),&c->nrows);CHKERRQ(ierr);
32   ierr       = PetscMalloc(nis*sizeof(int*),&c->rows);CHKERRQ(ierr);
33   ierr       = PetscMalloc(nis*sizeof(int*),&c->columnsforrow);CHKERRQ(ierr);
34 
35   /*
36       Calls the _SeqAIJ() version of these routines to make sure it does not
37      get the reduced (by inodes) version of I and J
38   */
39   ierr = MatGetColumnIJ_SeqAIJ(mat,0,PETSC_FALSE,&ncols,&ci,&cj,&done);CHKERRQ(ierr);
40 
41   /*
42      Temporary option to allow for debugging/testing
43   */
44   ierr = PetscOptionsHasName(PETSC_NULL,"-matfdcoloring_slow",&flg);CHKERRQ(ierr);
45 
46   ierr = PetscMalloc((N+1)*sizeof(int),&rowhit);CHKERRQ(ierr);
47   ierr = PetscMalloc((N+1)*sizeof(int),&columnsforrow);CHKERRQ(ierr);
48 
49   for (i=0; i<nis; i++) {
50     ierr = ISGetLocalSize(isa[i],&n);CHKERRQ(ierr);
51     ierr = ISGetIndices(isa[i],&is);CHKERRQ(ierr);
52     c->ncolumns[i] = n;
53     if (n) {
54       ierr = PetscMalloc(n*sizeof(int),&c->columns[i]);CHKERRQ(ierr);
55       ierr = PetscMemcpy(c->columns[i],is,n*sizeof(int));CHKERRQ(ierr);
56     } else {
57       c->columns[i]  = 0;
58     }
59 
60     if (flg) { /* ------------------------------------------------------------------------------*/
61       /* crude version requires O(N*N) work */
62       ierr = PetscMemzero(rowhit,N*sizeof(int));CHKERRQ(ierr);
63       /* loop over columns*/
64       for (j=0; j<n; j++) {
65         col  = is[j];
66         rows = cj + ci[col];
67         m    = ci[col+1] - ci[col];
68         /* loop over columns marking them in rowhit */
69         for (k=0; k<m; k++) {
70           rowhit[*rows++] = col + 1;
71         }
72       }
73       /* count the number of hits */
74       nrows = 0;
75       for (j=0; j<N; j++) {
76         if (rowhit[j]) nrows++;
77       }
78       c->nrows[i] = nrows;
79       ierr        = PetscMalloc(nrows*sizeof(int),&c->rows[i]);CHKERRQ(ierr);
80       ierr        = PetscMalloc(nrows*sizeof(int),&c->columnsforrow[i]);CHKERRQ(ierr);
81       nrows       = 0;
82       for (j=0; j<N; j++) {
83         if (rowhit[j]) {
84           c->rows[i][nrows]           = j;
85           c->columnsforrow[i][nrows] = rowhit[j] - 1;
86           nrows++;
87         }
88       }
89     } else {  /*-------------------------------------------------------------------------------*/
90       /* efficient version, using rowhit as a linked list */
91       int currentcol,fm,mfm;
92       rowhit[N] = N;
93       nrows     = 0;
94       /* loop over columns */
95       for (j=0; j<n; j++) {
96         col   = is[j];
97         rows  = cj + ci[col];
98         m     = ci[col+1] - ci[col];
99         /* loop over columns marking them in rowhit */
100         fm    = N; /* fm points to first entry in linked list */
101         for (k=0; k<m; k++) {
102           currentcol = *rows++;
103 	  /* is it already in the list? */
104           do {
105             mfm  = fm;
106             fm   = rowhit[fm];
107           } while (fm < currentcol);
108           /* not in list so add it */
109           if (fm != currentcol) {
110             nrows++;
111             columnsforrow[currentcol] = col;
112             /* next three lines insert new entry into linked list */
113             rowhit[mfm]               = currentcol;
114             rowhit[currentcol]        = fm;
115             fm                        = currentcol;
116             /* fm points to present position in list since we know the columns are sorted */
117           } else {
118             SETERRQ(PETSC_ERR_PLIB,"Detected invalid coloring");
119           }
120 
121         }
122       }
123       c->nrows[i] = nrows;
124       ierr        = PetscMalloc((nrows+1)*sizeof(int),&c->rows[i]);CHKERRQ(ierr);
125       ierr        = PetscMalloc((nrows+1)*sizeof(int),&c->columnsforrow[i]);CHKERRQ(ierr);
126       /* now store the linked list of rows into c->rows[i] */
127       nrows       = 0;
128       fm          = rowhit[N];
129       do {
130         c->rows[i][nrows]            = fm;
131         c->columnsforrow[i][nrows++] = columnsforrow[fm];
132         fm                           = rowhit[fm];
133       } while (fm < N);
134     } /* ---------------------------------------------------------------------------------------*/
135     ierr = ISRestoreIndices(isa[i],&is);CHKERRQ(ierr);
136   }
137   ierr = MatRestoreColumnIJ_SeqAIJ(mat,0,PETSC_FALSE,&ncols,&ci,&cj,&done);CHKERRQ(ierr);
138 
139   ierr = PetscFree(rowhit);CHKERRQ(ierr);
140   ierr = PetscFree(columnsforrow);CHKERRQ(ierr);
141 
142   /* Optimize by adding the vscale, and scaleforrow[][] fields */
143   /*
144        see the version for MPIAIJ
145   */
146   ierr = VecCreateGhost(mat->comm,mat->m,PETSC_DETERMINE,0,PETSC_NULL,&c->vscale);CHKERRQ(ierr)
147   ierr = PetscMalloc(c->ncolors*sizeof(int*),&c->vscaleforrow);CHKERRQ(ierr);
148   for (k=0; k<c->ncolors; k++) {
149     ierr = PetscMalloc((c->nrows[k]+1)*sizeof(int),&c->vscaleforrow[k]);CHKERRQ(ierr);
150     for (l=0; l<c->nrows[k]; l++) {
151       col = c->columnsforrow[k][l];
152       c->vscaleforrow[k][l] = col;
153     }
154   }
155 
156   PetscFunctionReturn(0);
157 }
158 
159 #undef __FUNC__
160 #define __FUNC__ "MatColoringPatch_SeqAIJ"
161 int MatColoringPatch_SeqAIJ(Mat mat,int ncolors,int *coloring,ISColoring *iscoloring)
162 {
163   int        n = mat->n,*sizes,i,**ii,ierr,tag;
164   IS         *is;
165 
166   PetscFunctionBegin;
167   /* construct the index sets from the coloring array */
168   ierr = PetscMalloc(ncolors*sizeof(int),&sizes);CHKERRQ(ierr);
169   ierr = PetscMemzero(sizes,ncolors*sizeof(int));CHKERRQ(ierr);
170   for (i=0; i<n; i++) {
171     sizes[coloring[i]-1]++;
172   }
173   ierr = PetscMalloc(ncolors*sizeof(int*),&ii);CHKERRQ(ierr);
174   ierr = PetscMalloc(n*sizeof(int),&ii[0]);CHKERRQ(ierr);
175   for (i=1; i<ncolors; i++) {
176     ii[i] = ii[i-1] + sizes[i-1];
177   }
178   ierr = PetscMemzero(sizes,ncolors*sizeof(int));CHKERRQ(ierr);
179   for (i=0; i<n; i++) {
180     ii[coloring[i]-1][sizes[coloring[i]-1]++] = i;
181   }
182   ierr = PetscMalloc(ncolors*sizeof(IS),&is);CHKERRQ(ierr);
183   for (i=0; i<ncolors; i++) {
184     ierr = ISCreateGeneral(PETSC_COMM_SELF,sizes[i],ii[i],is+i);CHKERRQ(ierr);
185   }
186 
187   ierr                = PetscNew(struct _p_ISColoring,iscoloring);CHKERRQ(ierr);
188   (*iscoloring)->n    = ncolors;
189   (*iscoloring)->is   = is;
190   ierr = PetscCommDuplicate_Private(mat->comm,&(*iscoloring)->comm,&tag);CHKERRQ(ierr);
191   ierr = PetscFree(sizes);CHKERRQ(ierr);
192   ierr = PetscFree(ii[0]);CHKERRQ(ierr);
193   ierr = PetscFree(ii);CHKERRQ(ierr);
194   PetscFunctionReturn(0);
195 }
196 
197 /*
198      Makes a longer coloring[] array and calls the usual code with that
199 */
200 #undef __FUNC__
201 #define __FUNC__ "MatColoringPatch_SeqAIJ_Inode"
202 int MatColoringPatch_SeqAIJ_Inode(Mat mat,int ncolors,int *coloring,ISColoring *iscoloring)
203 {
204   Mat_SeqAIJ *a = (Mat_SeqAIJ*)mat->data;
205   int        n = mat->n,ierr,m = a->inode.node_count,j,*ns = a->inode.size,row;
206   int        *colorused,i,*newcolor;
207 
208   PetscFunctionBegin;
209   ierr = PetscMalloc((n+1)*sizeof(int),&newcolor);CHKERRQ(ierr);
210 
211   /* loop over inodes, marking a color for each column*/
212   row = 0;
213   for (i=0; i<m; i++){
214     for (j=0; j<ns[i]; j++) {
215       newcolor[row++] = coloring[i] + j*ncolors;
216     }
217   }
218 
219   /* eliminate unneeded colors */
220   ierr = PetscMalloc(5*ncolors*sizeof(int),&colorused);CHKERRQ(ierr);
221   ierr = PetscMemzero(colorused,5*ncolors*sizeof(int));CHKERRQ(ierr);
222   for (i=0; i<n; i++) {
223     colorused[newcolor[i]-1] = 1;
224   }
225 
226   for (i=1; i<5*ncolors; i++) {
227     colorused[i] += colorused[i-1];
228   }
229   ncolors = colorused[5*ncolors-1];
230   for (i=0; i<n; i++) {
231     newcolor[i] = colorused[newcolor[i]-1];
232   }
233   ierr = PetscFree(colorused);CHKERRQ(ierr);
234 
235   ierr = MatColoringPatch_SeqAIJ(mat,ncolors,newcolor,iscoloring);CHKERRQ(ierr);
236   ierr = PetscFree(newcolor);CHKERRQ(ierr);
237 
238   PetscFunctionReturn(0);
239 }
240 
241 
242 
243 
244 
245 
246