xref: /petsc/src/mat/tests/ex185.c (revision c3b5f7ba6bc5ce25a01a67bb37ba5d34b02bbbd7)
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   PetscCall(PetscInitialize(&argc,&args,(char*)0,help));
14 
15   PetscCall(MatCreateConstantDiagonal(PETSC_COMM_WORLD,PETSC_DETERMINE,PETSC_DETERMINE,20,20,3.0,&A));
16   PetscCall(MatCreateVecs(A,&X,&Y));
17   PetscCall(MatView(A,PETSC_VIEWER_STDOUT_WORLD));
18 
19   PetscCall(VecSetRandom(X,NULL));
20   PetscCall(VecNorm(X,NORM_2,&xnorm));
21   PetscCall(MatMult(A,X,Y));
22   PetscCall(VecNorm(Y,NORM_2,&ynorm));
23   PetscCheckFalse(PetscAbsReal(ynorm - 3*xnorm) > PETSC_SMALL,PETSC_COMM_WORLD,PETSC_ERR_PLIB,"Expected norm %g actual norm %g",(double)(3*xnorm),(double)ynorm);
24   PetscCall(MatShift(A,5.0));
25   PetscCall(MatScale(A,.5));
26   PetscCall(MatView(A,PETSC_VIEWER_STDOUT_WORLD));
27   PetscCall(MatNorm(A,NORM_FROBENIUS,&anorm));
28   PetscCheckFalse(PetscAbsReal(anorm - 4.0) > PETSC_SMALL,PETSC_COMM_WORLD,PETSC_ERR_PLIB,"Expected norm 4.0 actual norm %g",(double)anorm);
29 
30   /* Convert to AIJ (exercises MatGetRow/MatRestoreRow) */
31   PetscCall(MatConvert(A,MATAIJ,MAT_INITIAL_MATRIX,&B));
32   PetscCall(MatMultEqual(A,B,10,&flg));
33   if (!flg) PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Error MatMult\n"));
34   PetscCall(MatMultAddEqual(A,B,10,&flg));
35   if (!flg) PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Error MatMultAdd\n"));
36   PetscCall(MatMultTransposeEqual(A,B,10,&flg));
37   if (!flg) PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Error MatMultTranspose\n"));
38   PetscCall(MatMultTransposeAddEqual(A,B,10,&flg));
39   if (!flg) PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Error MatMultTransposeAdd\n"));
40 
41   PetscCall(MatGetDiagonal(A,Y));
42   PetscCall(MatGetFactor(A,MATSOLVERPETSC,MAT_FACTOR_LU,&Af));
43   PetscCall(MatLUFactorSymbolic(Af,A,NULL,NULL,NULL));
44   PetscCall(MatLUFactorNumeric(Af,A,NULL));
45   PetscCall(MatSolve(Af,X,Y));
46   PetscCall(VecNorm(Y,NORM_2,&ynorm));
47   PetscCheckFalse(PetscAbsReal(ynorm - xnorm/4) > PETSC_SMALL,PETSC_COMM_WORLD,PETSC_ERR_PLIB,"Expected norm %g actual norm %g",(double)(.25*xnorm),(double)ynorm);
48 
49   PetscCall(MatDestroy(&A));
50   PetscCall(MatDestroy(&B));
51   PetscCall(MatDestroy(&Af));
52   PetscCall(VecDestroy(&X));
53   PetscCall(VecDestroy(&Y));
54 
55   PetscCall(PetscFinalize());
56   return 0;
57 }
58 
59 /*TEST
60 
61   test:
62     nsize: 2
63 
64 TEST*/
65