Actual source code: ex76.c

petsc-3.6.1 2015-08-06
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  2: static char help[] = "Tests cholesky, icc factorization and solve on sequential aij, baij and sbaij matrices. \n";

  4: #include <petscmat.h>

  8: int main(int argc,char **args)
  9: {
 10:   Vec            x,y,b;
 11:   Mat            A;           /* linear system matrix */
 12:   Mat            sA,sC;       /* symmetric part of the matrices */
 13:   PetscInt       n,mbs=16,bs=1,nz=3,prob=1,i,j,col[3],block, row,Ii,J,n1,lvl;
 15:   PetscMPIInt    size;
 16:   PetscReal      norm2,tol=1.e-10,err[10];
 17:   PetscScalar    neg_one = -1.0,four=4.0,value[3];
 18:   IS             perm,cperm;
 19:   PetscRandom    rdm;
 20:   PetscInt       reorder=0,displ=0;
 21:   MatFactorInfo  factinfo;
 22:   PetscBool      equal;
 23:   PetscBool      TestAIJ  =PETSC_FALSE,TestBAIJ=PETSC_TRUE;
 24:   PetscInt       TestShift=0;

 26:   PetscInitialize(&argc,&args,(char*)0,help);
 27:   MPI_Comm_size(PETSC_COMM_WORLD,&size);
 28:   if (size != 1) SETERRQ(PETSC_COMM_WORLD,1,"This is a uniprocessor example only!");
 29:   PetscOptionsGetInt(NULL,"-bs",&bs,NULL);
 30:   PetscOptionsGetInt(NULL,"-mbs",&mbs,NULL);
 31:   PetscOptionsGetInt(NULL,"-reorder",&reorder,NULL);
 32:   PetscOptionsGetBool(NULL,"-testaij",&TestAIJ,NULL);
 33:   PetscOptionsGetInt(NULL,"-testShift",&TestShift,NULL);
 34:   PetscOptionsGetInt(NULL,"-displ",&displ,NULL);

 36:   n = mbs*bs;
 37:   if (TestAIJ) { /* A is in aij format */
 38:     MatCreateSeqAIJ(PETSC_COMM_WORLD,n,n,nz,NULL,&A);
 39:     TestBAIJ = PETSC_FALSE;
 40:   } else { /* A is in baij format */
 41:     ierr    =MatCreateSeqBAIJ(PETSC_COMM_WORLD,bs,n,n,nz,NULL,&A);
 42:     TestAIJ = PETSC_FALSE;
 43:   }

 45:   /* Assemble matrix */
 46:   if (bs == 1) {
 47:     PetscOptionsGetInt(NULL,"-test_problem",&prob,NULL);
 48:     if (prob == 1) { /* tridiagonal matrix */
 49:       value[0] = -1.0; value[1] = 2.0; value[2] = -1.0;
 50:       for (i=1; i<n-1; i++) {
 51:         col[0] = i-1; col[1] = i; col[2] = i+1;
 52:         MatSetValues(A,1,&i,3,col,value,INSERT_VALUES);
 53:       }
 54:       i = n - 1; col[0]=0; col[1] = n - 2; col[2] = n - 1;

 56:       value[0]= 0.1; value[1]=-1; value[2]=2;
 57:       MatSetValues(A,1,&i,3,col,value,INSERT_VALUES);

 59:       i = 0; col[0] = 0; col[1] = 1; col[2]=n-1;

 61:       value[0] = 2.0; value[1] = -1.0; value[2]=0.1;
 62:       MatSetValues(A,1,&i,3,col,value,INSERT_VALUES);
 63:     } else if (prob ==2) { /* matrix for the five point stencil */
 64:       n1 = (PetscInt) (PetscSqrtReal((PetscReal)n) + 0.001);
 65:       if (n1*n1 - n) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"sqrt(n) must be a positive interger!");
 66:       for (i=0; i<n1; i++) {
 67:         for (j=0; j<n1; j++) {
 68:           Ii = j + n1*i;
 69:           if (i>0) {
 70:             J    = Ii - n1;
 71:             MatSetValues(A,1,&Ii,1,&J,&neg_one,INSERT_VALUES);
 72:           }
 73:           if (i<n1-1) {
 74:             J    = Ii + n1;
 75:             MatSetValues(A,1,&Ii,1,&J,&neg_one,INSERT_VALUES);
 76:           }
 77:           if (j>0) {
 78:             J    = Ii - 1;
 79:             MatSetValues(A,1,&Ii,1,&J,&neg_one,INSERT_VALUES);
 80:           }
 81:           if (j<n1-1) {
 82:             J    = Ii + 1;
 83:             MatSetValues(A,1,&Ii,1,&J,&neg_one,INSERT_VALUES);
 84:           }
 85:           MatSetValues(A,1,&Ii,1,&Ii,&four,INSERT_VALUES);
 86:         }
 87:       }
 88:     }
 89:   } else { /* bs > 1 */
 90:     for (block=0; block<n/bs; block++) {
 91:       /* diagonal blocks */
 92:       value[0] = -1.0; value[1] = 4.0; value[2] = -1.0;
 93:       for (i=1+block*bs; i<bs-1+block*bs; i++) {
 94:         col[0] = i-1; col[1] = i; col[2] = i+1;
 95:         MatSetValues(A,1,&i,3,col,value,INSERT_VALUES);
 96:       }
 97:       i = bs - 1+block*bs; col[0] = bs - 2+block*bs; col[1] = bs - 1+block*bs;

 99:       value[0]=-1.0; value[1]=4.0;
100:       MatSetValues(A,1,&i,2,col,value,INSERT_VALUES);

102:       i = 0+block*bs; col[0] = 0+block*bs; col[1] = 1+block*bs;

104:       value[0]=4.0; value[1] = -1.0;
105:       MatSetValues(A,1,&i,2,col,value,INSERT_VALUES);
106:     }
107:     /* off-diagonal blocks */
108:     value[0]=-1.0;
109:     for (i=0; i<(n/bs-1)*bs; i++) {
110:       col[0]=i+bs;
111:       MatSetValues(A,1,&i,1,col,value,INSERT_VALUES);
112:       col[0]=i; row=i+bs;
113:       MatSetValues(A,1,&row,1,col,value,INSERT_VALUES);
114:     }
115:   }

117:   if (TestShift) {
118:     /* set diagonals in the 0-th block as 0 for testing shift numerical factor */
119:     for (i=0; i<bs; i++) {
120:       row  = i; col[0] = i; value[0] = 0.0;
121:       MatSetValues(A,1,&row,1,col,value,INSERT_VALUES);
122:     }
123:   }

125:   MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
126:   MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);

128:   /* Test MatConvert */
129:   MatSetOption(A,MAT_SYMMETRIC,PETSC_TRUE);
130:   MatConvert(A,MATSEQSBAIJ,MAT_INITIAL_MATRIX,&sA);
131:   MatMultEqual(A,sA,20,&equal);
132:   if (!equal) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_USER,"A != sA");

134:   /* Test MatGetOwnershipRange() */
135:   MatGetOwnershipRange(A,&Ii,&J);
136:   MatGetOwnershipRange(sA,&i,&j);
137:   if (i-Ii || j-J) {
138:     PetscPrintf(PETSC_COMM_SELF,"Error: MatGetOwnershipRange() in MatSBAIJ format\n");
139:   }

141:   /* Vectors */
142:   PetscRandomCreate(PETSC_COMM_SELF,&rdm);
143:   PetscRandomSetFromOptions(rdm);
144:   VecCreateSeq(PETSC_COMM_SELF,n,&x);
145:   VecDuplicate(x,&b);
146:   VecDuplicate(x,&y);
147:   VecSetRandom(x,rdm);

149:   /* Test MatReordering() - not work on sbaij matrix */
150:   if (reorder) {
151:     MatGetOrdering(A,MATORDERINGRCM,&perm,&cperm);
152:   } else {
153:     MatGetOrdering(A,MATORDERINGNATURAL,&perm,&cperm);
154:   }
155:   ISDestroy(&cperm);

157:   /* initialize factinfo */
158:   MatFactorInfoInitialize(&factinfo);
159:   if (TestShift == 1) {
160:     factinfo.shifttype   = (PetscReal)MAT_SHIFT_NONZERO;
161:     factinfo.shiftamount = 0.1;
162:   } else if (TestShift == 2) {
163:     factinfo.shifttype = (PetscReal)MAT_SHIFT_POSITIVE_DEFINITE;
164:   }

166:   /* Test MatCholeskyFactor(), MatICCFactor() */
167:   /*------------------------------------------*/
168:   /* Test aij matrix A */
169:   if (TestAIJ) {
170:     if (displ>0) {
171:       PetscPrintf(PETSC_COMM_SELF,"AIJ: \n");
172:     }
173:     i = 0;
174:     for (lvl=-1; lvl<10; lvl++) {
175:       if (lvl==-1) {  /* Cholesky factor */
176:         factinfo.fill = 5.0;

178:         MatGetFactor(A,MATSOLVERPETSC,MAT_FACTOR_CHOLESKY,&sC);
179:         MatCholeskyFactorSymbolic(sC,A,perm,&factinfo);
180:       } else {       /* incomplete Cholesky factor */
181:         factinfo.fill   = 5.0;
182:         factinfo.levels = lvl;

184:         MatGetFactor(A,MATSOLVERPETSC,MAT_FACTOR_ICC,&sC);
185:         MatICCFactorSymbolic(sC,A,perm,&factinfo);
186:       }
187:       MatCholeskyFactorNumeric(sC,A,&factinfo);

189:       MatMult(A,x,b);
190:       MatSolve(sC,b,y);
191:       MatDestroy(&sC);

193:       /* Check the error */
194:       VecAXPY(y,neg_one,x);
195:       VecNorm(y,NORM_2,&norm2);

197:       if (displ>0) {
198:         PetscPrintf(PETSC_COMM_SELF,"  lvl: %D, error: %g\n", lvl,(double)norm2);
199:       }
200:       err[i++] = norm2;
201:     }
202:   }

204:   /* Test baij matrix A */
205:   if (TestBAIJ) {
206:     if (displ>0) {
207:       PetscPrintf(PETSC_COMM_SELF,"BAIJ: \n");
208:     }
209:     i = 0;
210:     for (lvl=-1; lvl<10; lvl++) {
211:       if (lvl==-1) {  /* Cholesky factor */
212:         factinfo.fill = 5.0;

214:         MatGetFactor(A,MATSOLVERPETSC,MAT_FACTOR_CHOLESKY,&sC);
215:         MatCholeskyFactorSymbolic(sC,A,perm,&factinfo);
216:       } else {       /* incomplete Cholesky factor */
217:         factinfo.fill   = 5.0;
218:         factinfo.levels = lvl;

220:         MatGetFactor(A,MATSOLVERPETSC,MAT_FACTOR_ICC,&sC);
221:         MatICCFactorSymbolic(sC,A,perm,&factinfo);
222:       }
223:       MatCholeskyFactorNumeric(sC,A,&factinfo);

225:       MatMult(A,x,b);
226:       MatSolve(sC,b,y);
227:       MatDestroy(&sC);

229:       /* Check the error */
230:       VecAXPY(y,neg_one,x);
231:       VecNorm(y,NORM_2,&norm2);
232:       if (displ>0) {
233:         PetscPrintf(PETSC_COMM_SELF,"  lvl: %D, error: %g\n", lvl,(double)norm2);
234:       }
235:       err[i++] = norm2;
236:     }
237:   }

239:   /* Test sbaij matrix sA */
240:   if (displ>0) {
241:     PetscPrintf(PETSC_COMM_SELF,"SBAIJ: \n");
242:   }
243:   i = 0;
244:   for (lvl=-1; lvl<10; lvl++) {
245:     if (lvl==-1) {  /* Cholesky factor */
246:       factinfo.fill = 5.0;

248:       MatGetFactor(sA,MATSOLVERPETSC,MAT_FACTOR_CHOLESKY,&sC);
249:       MatCholeskyFactorSymbolic(sC,sA,perm,&factinfo);
250:     } else {       /* incomplete Cholesky factor */
251:       factinfo.fill   = 5.0;
252:       factinfo.levels = lvl;

254:       MatGetFactor(sA,MATSOLVERPETSC,MAT_FACTOR_ICC,&sC);
255:       MatICCFactorSymbolic(sC,sA,perm,&factinfo);
256:     }
257:     MatCholeskyFactorNumeric(sC,sA,&factinfo);

259:     if (lvl==0 && bs==1) { /* Test inplace ICC(0) for sbaij sA - does not work for new datastructure */
260:       /*
261:         Mat B;
262:         MatDuplicate(sA,MAT_COPY_VALUES,&B);
263:         MatICCFactor(B,perm,&factinfo);
264:         MatEqual(sC,B,&equal);
265:         if (!equal) {
266:           SETERRQ(PETSC_COMM_SELF,PETSC_ERR_USER,"in-place Cholesky factor != out-place Cholesky factor");
267:         }
268:         MatDestroy(&B);
269:       */
270:     }


273:     MatMult(sA,x,b);
274:     MatSolve(sC,b,y);

276:     /* Test MatSolves() */
277:     if (bs == 1) {
278:       Vecs xx,bb;
279:       VecsCreateSeq(PETSC_COMM_SELF,n,4,&xx);
280:       VecsDuplicate(xx,&bb);
281:       MatSolves(sC,bb,xx);
282:       VecsDestroy(xx);
283:       VecsDestroy(bb);
284:     }
285:     MatDestroy(&sC);

287:     /* Check the error */
288:     VecAXPY(y,neg_one,x);
289:     VecNorm(y,NORM_2,&norm2);
290:     if (displ>0) {
291:       PetscPrintf(PETSC_COMM_SELF,"  lvl: %D, error: %g\n", lvl,(double)norm2);
292:     }
293:     err[i] -= norm2;
294:     if (err[i] > tol) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_USER," level: %d, err: %g\n", lvl,(double)err[i]);
295:   }

297:   ISDestroy(&perm);
298:   MatDestroy(&A);
299:   MatDestroy(&sA);
300:   VecDestroy(&x);
301:   VecDestroy(&y);
302:   VecDestroy(&b);
303:   PetscRandomDestroy(&rdm);

305:   PetscFinalize();
306:   return 0;
307: }