xref: /petsc/src/mat/tests/ex15.c (revision 2c71b3e237ead271e4f3aa1505f92bf476e3413d)
1c4762a1bSJed Brown 
2c4762a1bSJed Brown static char help[] = "Tests MatNorm(), MatLUFactor(), MatSolve() and MatSolveAdd().\n\n";
3c4762a1bSJed Brown 
4c4762a1bSJed Brown #include <petscmat.h>
5c4762a1bSJed Brown 
6c4762a1bSJed Brown int main(int argc,char **args)
7c4762a1bSJed Brown {
8c4762a1bSJed Brown   Mat            C;
9c4762a1bSJed Brown   PetscInt       i,j,m = 3,n = 3,Ii,J;
10c4762a1bSJed Brown   PetscErrorCode ierr;
11c4762a1bSJed Brown   PetscBool      flg;
12c4762a1bSJed Brown   PetscScalar    v;
13c4762a1bSJed Brown   IS             perm,iperm;
14c4762a1bSJed Brown   Vec            x,u,b,y;
15c4762a1bSJed Brown   PetscReal      norm,tol=PETSC_SMALL;
16c4762a1bSJed Brown   MatFactorInfo  info;
17c4762a1bSJed Brown   PetscMPIInt    size;
18c4762a1bSJed Brown 
19c4762a1bSJed Brown   ierr = PetscInitialize(&argc,&args,(char*)0,help);if (ierr) return ierr;
20ffc4695bSBarry Smith   ierr = MPI_Comm_size(PETSC_COMM_WORLD,&size);CHKERRMPI(ierr);
21*2c71b3e2SJacob Faibussowitsch   PetscCheckFalse(size != 1,PETSC_COMM_WORLD,PETSC_ERR_WRONG_MPI_SIZE,"This is a uniprocessor example only!");
22c4762a1bSJed Brown   ierr = MatCreate(PETSC_COMM_WORLD,&C);CHKERRQ(ierr);
23c4762a1bSJed Brown   ierr = MatSetSizes(C,PETSC_DECIDE,PETSC_DECIDE,m*n,m*n);CHKERRQ(ierr);
24c4762a1bSJed Brown   ierr = MatSetFromOptions(C);CHKERRQ(ierr);
25c4762a1bSJed Brown   ierr = MatSetUp(C);CHKERRQ(ierr);
26c4762a1bSJed Brown   ierr = PetscOptionsHasName(NULL,NULL,"-symmetric",&flg);CHKERRQ(ierr);
27c4762a1bSJed Brown   if (flg) {  /* Treat matrix as symmetric only if we set this flag */
28c4762a1bSJed Brown     ierr = MatSetOption(C,MAT_SYMMETRIC,PETSC_TRUE);CHKERRQ(ierr);
29c4762a1bSJed Brown     ierr = MatSetOption(C,MAT_SYMMETRY_ETERNAL,PETSC_TRUE);CHKERRQ(ierr);
30c4762a1bSJed Brown   }
31c4762a1bSJed Brown 
32c4762a1bSJed Brown   /* Create the matrix for the five point stencil, YET AGAIN */
33c4762a1bSJed Brown   for (i=0; i<m; i++) {
34c4762a1bSJed Brown     for (j=0; j<n; j++) {
35c4762a1bSJed Brown       v = -1.0;  Ii = j + n*i;
36c4762a1bSJed Brown       if (i>0)   {J = Ii - n; ierr = MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);CHKERRQ(ierr);}
37c4762a1bSJed Brown       if (i<m-1) {J = Ii + n; ierr = MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);CHKERRQ(ierr);}
38c4762a1bSJed Brown       if (j>0)   {J = Ii - 1; ierr = MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);CHKERRQ(ierr);}
39c4762a1bSJed Brown       if (j<n-1) {J = Ii + 1; ierr = MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);CHKERRQ(ierr);}
40c4762a1bSJed Brown       v = 4.0; ierr = MatSetValues(C,1,&Ii,1,&Ii,&v,INSERT_VALUES);CHKERRQ(ierr);
41c4762a1bSJed Brown     }
42c4762a1bSJed Brown   }
43c4762a1bSJed Brown   ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
44c4762a1bSJed Brown   ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
45c4762a1bSJed Brown   ierr = MatGetOrdering(C,MATORDERINGRCM,&perm,&iperm);CHKERRQ(ierr);
46c4762a1bSJed Brown   ierr = MatView(C,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
47c4762a1bSJed Brown   ierr = ISView(perm,PETSC_VIEWER_STDOUT_SELF);CHKERRQ(ierr);
48c4762a1bSJed Brown   ierr = VecCreateSeq(PETSC_COMM_SELF,m*n,&u);CHKERRQ(ierr);
49c4762a1bSJed Brown   ierr = VecSet(u,1.0);CHKERRQ(ierr);
50c4762a1bSJed Brown   ierr = VecDuplicate(u,&x);CHKERRQ(ierr);
51c4762a1bSJed Brown   ierr = VecDuplicate(u,&b);CHKERRQ(ierr);
52c4762a1bSJed Brown   ierr = VecDuplicate(u,&y);CHKERRQ(ierr);
53c4762a1bSJed Brown   ierr = MatMult(C,u,b);CHKERRQ(ierr);
54c4762a1bSJed Brown   ierr = VecCopy(b,y);CHKERRQ(ierr);
55c4762a1bSJed Brown   ierr = VecScale(y,2.0);CHKERRQ(ierr);
56c4762a1bSJed Brown 
57c4762a1bSJed Brown   ierr = MatNorm(C,NORM_FROBENIUS,&norm);CHKERRQ(ierr);
58c4762a1bSJed Brown   ierr = PetscPrintf(PETSC_COMM_SELF,"Frobenius norm of matrix %g\n",(double)norm);CHKERRQ(ierr);
59c4762a1bSJed Brown   ierr = MatNorm(C,NORM_1,&norm);CHKERRQ(ierr);
60c4762a1bSJed Brown   ierr = PetscPrintf(PETSC_COMM_SELF,"One  norm of matrix %g\n",(double)norm);CHKERRQ(ierr);
61c4762a1bSJed Brown   ierr = MatNorm(C,NORM_INFINITY,&norm);CHKERRQ(ierr);
62c4762a1bSJed Brown   ierr = PetscPrintf(PETSC_COMM_SELF,"Infinity norm of matrix %g\n",(double)norm);CHKERRQ(ierr);
63c4762a1bSJed Brown 
64c4762a1bSJed Brown   ierr               = MatFactorInfoInitialize(&info);CHKERRQ(ierr);
65c4762a1bSJed Brown   info.fill          = 2.0;
66c4762a1bSJed Brown   info.dtcol         = 0.0;
67c4762a1bSJed Brown   info.zeropivot     = 1.e-14;
68c4762a1bSJed Brown   info.pivotinblocks = 1.0;
69c4762a1bSJed Brown 
70c4762a1bSJed Brown   ierr = MatLUFactor(C,perm,iperm,&info);CHKERRQ(ierr);
71c4762a1bSJed Brown 
72c4762a1bSJed Brown   /* Test MatSolve */
73c4762a1bSJed Brown   ierr = MatSolve(C,b,x);CHKERRQ(ierr);
74c4762a1bSJed Brown   ierr = VecView(b,PETSC_VIEWER_STDOUT_SELF);CHKERRQ(ierr);
75c4762a1bSJed Brown   ierr = VecView(x,PETSC_VIEWER_STDOUT_SELF);CHKERRQ(ierr);
76c4762a1bSJed Brown   ierr = VecAXPY(x,-1.0,u);CHKERRQ(ierr);
77c4762a1bSJed Brown   ierr = VecNorm(x,NORM_2,&norm);CHKERRQ(ierr);
78c4762a1bSJed Brown   if (norm > tol) {
79c4762a1bSJed Brown     ierr = PetscPrintf(PETSC_COMM_SELF,"MatSolve: Norm of error %g\n",(double)norm);CHKERRQ(ierr);
80c4762a1bSJed Brown   }
81c4762a1bSJed Brown 
82c4762a1bSJed Brown   /* Test MatSolveAdd */
83c4762a1bSJed Brown   ierr = MatSolveAdd(C,b,y,x);CHKERRQ(ierr);
84c4762a1bSJed Brown   ierr = VecAXPY(x,-1.0,y);CHKERRQ(ierr);
85c4762a1bSJed Brown   ierr = VecAXPY(x,-1.0,u);CHKERRQ(ierr);
86c4762a1bSJed Brown   ierr = VecNorm(x,NORM_2,&norm);CHKERRQ(ierr);
87c4762a1bSJed Brown   if (norm > tol) {
88c4762a1bSJed Brown     ierr = PetscPrintf(PETSC_COMM_SELF,"MatSolveAdd(): Norm of error %g\n",(double)norm);CHKERRQ(ierr);
89c4762a1bSJed Brown   }
90c4762a1bSJed Brown 
91c4762a1bSJed Brown   ierr = ISDestroy(&perm);CHKERRQ(ierr);
92c4762a1bSJed Brown   ierr = ISDestroy(&iperm);CHKERRQ(ierr);
93c4762a1bSJed Brown   ierr = VecDestroy(&u);CHKERRQ(ierr);
94c4762a1bSJed Brown   ierr = VecDestroy(&y);CHKERRQ(ierr);
95c4762a1bSJed Brown   ierr = VecDestroy(&b);CHKERRQ(ierr);
96c4762a1bSJed Brown   ierr = VecDestroy(&x);CHKERRQ(ierr);
97c4762a1bSJed Brown   ierr = MatDestroy(&C);CHKERRQ(ierr);
98c4762a1bSJed Brown   ierr = PetscFinalize();
99c4762a1bSJed Brown   return ierr;
100c4762a1bSJed Brown }
101c4762a1bSJed Brown 
102c4762a1bSJed Brown /*TEST
103c4762a1bSJed Brown 
104c4762a1bSJed Brown    test:
105c4762a1bSJed Brown 
106c4762a1bSJed Brown TEST*/
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