1 2 static char help[] = "Tests MatNorm(), MatLUFactor(), MatSolve() and MatSolveAdd().\n\n"; 3 4 #include <petscmat.h> 5 6 int main(int argc,char **args) 7 { 8 Mat C; 9 PetscInt i,j,m = 3,n = 3,Ii,J; 10 PetscErrorCode ierr; 11 PetscBool flg; 12 PetscScalar v; 13 IS perm,iperm; 14 Vec x,u,b,y; 15 PetscReal norm,tol=PETSC_SMALL; 16 MatFactorInfo info; 17 PetscMPIInt size; 18 19 ierr = PetscInitialize(&argc,&args,(char*)0,help);if (ierr) return ierr; 20 CHKERRMPI(MPI_Comm_size(PETSC_COMM_WORLD,&size)); 21 PetscCheckFalse(size != 1,PETSC_COMM_WORLD,PETSC_ERR_WRONG_MPI_SIZE,"This is a uniprocessor example only!"); 22 CHKERRQ(MatCreate(PETSC_COMM_WORLD,&C)); 23 CHKERRQ(MatSetSizes(C,PETSC_DECIDE,PETSC_DECIDE,m*n,m*n)); 24 CHKERRQ(MatSetFromOptions(C)); 25 CHKERRQ(MatSetUp(C)); 26 CHKERRQ(PetscOptionsHasName(NULL,NULL,"-symmetric",&flg)); 27 if (flg) { /* Treat matrix as symmetric only if we set this flag */ 28 CHKERRQ(MatSetOption(C,MAT_SYMMETRIC,PETSC_TRUE)); 29 CHKERRQ(MatSetOption(C,MAT_SYMMETRY_ETERNAL,PETSC_TRUE)); 30 } 31 32 /* Create the matrix for the five point stencil, YET AGAIN */ 33 for (i=0; i<m; i++) { 34 for (j=0; j<n; j++) { 35 v = -1.0; Ii = j + n*i; 36 if (i>0) {J = Ii - n; CHKERRQ(MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES));} 37 if (i<m-1) {J = Ii + n; CHKERRQ(MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES));} 38 if (j>0) {J = Ii - 1; CHKERRQ(MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES));} 39 if (j<n-1) {J = Ii + 1; CHKERRQ(MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES));} 40 v = 4.0; CHKERRQ(MatSetValues(C,1,&Ii,1,&Ii,&v,INSERT_VALUES)); 41 } 42 } 43 CHKERRQ(MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY)); 44 CHKERRQ(MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY)); 45 CHKERRQ(MatGetOrdering(C,MATORDERINGRCM,&perm,&iperm)); 46 CHKERRQ(MatView(C,PETSC_VIEWER_STDOUT_WORLD)); 47 CHKERRQ(ISView(perm,PETSC_VIEWER_STDOUT_SELF)); 48 CHKERRQ(VecCreateSeq(PETSC_COMM_SELF,m*n,&u)); 49 CHKERRQ(VecSet(u,1.0)); 50 CHKERRQ(VecDuplicate(u,&x)); 51 CHKERRQ(VecDuplicate(u,&b)); 52 CHKERRQ(VecDuplicate(u,&y)); 53 CHKERRQ(MatMult(C,u,b)); 54 CHKERRQ(VecCopy(b,y)); 55 CHKERRQ(VecScale(y,2.0)); 56 57 CHKERRQ(MatNorm(C,NORM_FROBENIUS,&norm)); 58 CHKERRQ(PetscPrintf(PETSC_COMM_SELF,"Frobenius norm of matrix %g\n",(double)norm)); 59 CHKERRQ(MatNorm(C,NORM_1,&norm)); 60 CHKERRQ(PetscPrintf(PETSC_COMM_SELF,"One norm of matrix %g\n",(double)norm)); 61 CHKERRQ(MatNorm(C,NORM_INFINITY,&norm)); 62 CHKERRQ(PetscPrintf(PETSC_COMM_SELF,"Infinity norm of matrix %g\n",(double)norm)); 63 64 CHKERRQ(MatFactorInfoInitialize(&info)); 65 info.fill = 2.0; 66 info.dtcol = 0.0; 67 info.zeropivot = 1.e-14; 68 info.pivotinblocks = 1.0; 69 70 CHKERRQ(MatLUFactor(C,perm,iperm,&info)); 71 72 /* Test MatSolve */ 73 CHKERRQ(MatSolve(C,b,x)); 74 CHKERRQ(VecView(b,PETSC_VIEWER_STDOUT_SELF)); 75 CHKERRQ(VecView(x,PETSC_VIEWER_STDOUT_SELF)); 76 CHKERRQ(VecAXPY(x,-1.0,u)); 77 CHKERRQ(VecNorm(x,NORM_2,&norm)); 78 if (norm > tol) { 79 CHKERRQ(PetscPrintf(PETSC_COMM_SELF,"MatSolve: Norm of error %g\n",(double)norm)); 80 } 81 82 /* Test MatSolveAdd */ 83 CHKERRQ(MatSolveAdd(C,b,y,x)); 84 CHKERRQ(VecAXPY(x,-1.0,y)); 85 CHKERRQ(VecAXPY(x,-1.0,u)); 86 CHKERRQ(VecNorm(x,NORM_2,&norm)); 87 if (norm > tol) { 88 CHKERRQ(PetscPrintf(PETSC_COMM_SELF,"MatSolveAdd(): Norm of error %g\n",(double)norm)); 89 } 90 91 CHKERRQ(ISDestroy(&perm)); 92 CHKERRQ(ISDestroy(&iperm)); 93 CHKERRQ(VecDestroy(&u)); 94 CHKERRQ(VecDestroy(&y)); 95 CHKERRQ(VecDestroy(&b)); 96 CHKERRQ(VecDestroy(&x)); 97 CHKERRQ(MatDestroy(&C)); 98 ierr = PetscFinalize(); 99 return ierr; 100 } 101 102 /*TEST 103 104 test: 105 106 TEST*/ 107