xref: /petsc/src/mat/tests/ex185.c (revision ebead697dbf761eb322f829370bbe90b3bd93fa3)
1 static char help[] = "Tests MatCreateConstantDiagonal().\n"
2 "\n";
3 
4 #include <petscmat.h>
5 
6 int main(int argc, char **args)
7 {
8   Vec            X, Y;
9   Mat            A,B,Af;
10   PetscBool      flg;
11   PetscReal      xnorm,ynorm,anorm;
12 
13   PetscFunctionBeginUser;
14   PetscCall(PetscInitialize(&argc,&args,(char*)0,help));
15 
16   PetscCall(MatCreateConstantDiagonal(PETSC_COMM_WORLD,PETSC_DETERMINE,PETSC_DETERMINE,20,20,3.0,&A));
17   PetscCall(MatCreateVecs(A,&X,&Y));
18   PetscCall(MatView(A,PETSC_VIEWER_STDOUT_WORLD));
19 
20   PetscCall(VecSetRandom(X,NULL));
21   PetscCall(VecNorm(X,NORM_2,&xnorm));
22   PetscCall(MatMult(A,X,Y));
23   PetscCall(VecNorm(Y,NORM_2,&ynorm));
24   PetscCheck(PetscAbsReal(ynorm - 3*xnorm) <= PETSC_SMALL,PETSC_COMM_WORLD,PETSC_ERR_PLIB,"Expected norm %g actual norm %g",(double)(3*xnorm),(double)ynorm);
25   PetscCall(MatShift(A,5.0));
26   PetscCall(MatScale(A,.5));
27   PetscCall(MatView(A,PETSC_VIEWER_STDOUT_WORLD));
28   PetscCall(MatNorm(A,NORM_FROBENIUS,&anorm));
29   PetscCheck(PetscAbsReal(anorm - 4.0) <= PETSC_SMALL,PETSC_COMM_WORLD,PETSC_ERR_PLIB,"Expected norm 4.0 actual norm %g",(double)anorm);
30 
31   /* Convert to AIJ (exercises MatGetRow/MatRestoreRow) */
32   PetscCall(MatConvert(A,MATAIJ,MAT_INITIAL_MATRIX,&B));
33   PetscCall(MatMultEqual(A,B,10,&flg));
34   if (!flg) PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Error MatMult\n"));
35   PetscCall(MatMultAddEqual(A,B,10,&flg));
36   if (!flg) PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Error MatMultAdd\n"));
37   PetscCall(MatMultTransposeEqual(A,B,10,&flg));
38   if (!flg) PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Error MatMultTranspose\n"));
39   PetscCall(MatMultTransposeAddEqual(A,B,10,&flg));
40   if (!flg) PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Error MatMultTransposeAdd\n"));
41 
42   PetscCall(MatGetDiagonal(A,Y));
43   PetscCall(MatGetFactor(A,MATSOLVERPETSC,MAT_FACTOR_LU,&Af));
44   PetscCall(MatLUFactorSymbolic(Af,A,NULL,NULL,NULL));
45   PetscCall(MatLUFactorNumeric(Af,A,NULL));
46   PetscCall(MatSolve(Af,X,Y));
47   PetscCall(VecNorm(Y,NORM_2,&ynorm));
48   PetscCheck(PetscAbsReal(ynorm - xnorm/4) <= PETSC_SMALL,PETSC_COMM_WORLD,PETSC_ERR_PLIB,"Expected norm %g actual norm %g",(double)(.25*xnorm),(double)ynorm);
49 
50   PetscCall(MatDestroy(&A));
51   PetscCall(MatDestroy(&B));
52   PetscCall(MatDestroy(&Af));
53   PetscCall(VecDestroy(&X));
54   PetscCall(VecDestroy(&Y));
55 
56   PetscCall(PetscFinalize());
57   return 0;
58 }
59 
60 /*TEST
61 
62   test:
63     nsize: 2
64 
65 TEST*/
66