xref: /petsc/src/mat/tests/ex185.c (revision 6a98f8dc3f2c9149905a87dc2e9d0fedaf64e09a)
1 static char help[] = "Tests MatCreateConstantDiagonal().\n"
2 "\n";
3 
4 #include <petscmat.h>
5 
6 /*T
7     Concepts: Mat
8 T*/
9 
10 int main(int argc, char **args)
11 {
12   PetscErrorCode ierr;
13   Vec            X, Y;
14   Mat            A,B,Af;
15   PetscBool      flg;
16   PetscReal      xnorm,ynorm;
17 
18   ierr = PetscInitialize(&argc,&args,(char*)0,help);if (ierr) return ierr;
19 
20   ierr = MatCreateConstantDiagonal(PETSC_COMM_WORLD,PETSC_DETERMINE,PETSC_DETERMINE,20,20,3.0,&A);CHKERRQ(ierr);
21   ierr = MatCreateVecs(A,&X,&Y);CHKERRQ(ierr);
22   ierr = MatView(A,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
23 
24   ierr = VecSetRandom(X,NULL);CHKERRQ(ierr);
25   ierr = VecNorm(X,NORM_2,&xnorm);CHKERRQ(ierr);
26   ierr = MatMult(A,X,Y);CHKERRQ(ierr);
27   ierr = VecNorm(Y,NORM_2,&ynorm);CHKERRQ(ierr);
28   if (PetscAbsReal(ynorm - 3*xnorm) > PETSC_SMALL) SETERRQ2(PETSC_COMM_WORLD,PETSC_ERR_PLIB,"Expected norm %g actual norm %g\n",(double)3*xnorm,(double)ynorm);CHKERRQ(ierr);
29   ierr = MatShift(A,5.0);CHKERRQ(ierr);
30   ierr = MatScale(A,.5);CHKERRQ(ierr);
31   ierr = MatView(A,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
32 
33   /* Convert to AIJ (exercises MatGetRow/MatRestoreRow) */
34   ierr = MatConvert(A,MATAIJ,MAT_INITIAL_MATRIX,&B);CHKERRQ(ierr);
35   ierr = MatMultEqual(A,B,10,&flg);CHKERRQ(ierr);
36   if (!flg) { ierr = PetscPrintf(PETSC_COMM_WORLD,"Error MatMult\n");CHKERRQ(ierr); }
37   ierr = MatMultAddEqual(A,B,10,&flg);CHKERRQ(ierr);
38   if (!flg) { ierr = PetscPrintf(PETSC_COMM_WORLD,"Error MatMultAdd\n");CHKERRQ(ierr); }
39   ierr = MatMultTransposeEqual(A,B,10,&flg);CHKERRQ(ierr);
40   if (!flg) { ierr = PetscPrintf(PETSC_COMM_WORLD,"Error MatMultTranspose\n");CHKERRQ(ierr); }
41   ierr = MatMultTransposeAddEqual(A,B,10,&flg);CHKERRQ(ierr);
42   if (!flg) { ierr = PetscPrintf(PETSC_COMM_WORLD,"Error MatMultTransposeAdd\n");CHKERRQ(ierr); }
43 
44   ierr = MatGetDiagonal(A,Y);CHKERRQ(ierr);
45   ierr = MatGetFactor(A,MATSOLVERPETSC,MAT_FACTOR_LU,&Af);CHKERRQ(ierr);
46   ierr = MatLUFactorSymbolic(Af,A,NULL,NULL,NULL);CHKERRQ(ierr);
47   ierr = MatLUFactorNumeric(Af,A,NULL);CHKERRQ(ierr);
48   ierr = MatSolve(Af,X,Y);CHKERRQ(ierr);
49   ierr = VecNorm(Y,NORM_2,&ynorm);CHKERRQ(ierr);
50   if (PetscAbsReal(ynorm - xnorm/4) > PETSC_SMALL) SETERRQ2(PETSC_COMM_WORLD,PETSC_ERR_PLIB,"Expected norm %g actual norm %g\n",(double).25*xnorm,(double)ynorm);CHKERRQ(ierr);
51 
52   ierr = MatDestroy(&A);CHKERRQ(ierr);
53   ierr = MatDestroy(&B);CHKERRQ(ierr);
54   ierr = MatDestroy(&Af);CHKERRQ(ierr);
55   ierr = VecDestroy(&X);CHKERRQ(ierr);
56   ierr = VecDestroy(&Y);CHKERRQ(ierr);
57 
58   ierr = PetscFinalize();
59   return ierr;
60 }
61 
62 /*TEST
63 
64   test:
65     nsize: 2
66 
67 TEST*/
68