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 PetscBool flg; 11 PetscScalar v; 12 IS perm,iperm; 13 Vec x,u,b,y; 14 PetscReal norm,tol=PETSC_SMALL; 15 MatFactorInfo info; 16 PetscMPIInt size; 17 18 PetscFunctionBeginUser; 19 PetscCall(PetscInitialize(&argc,&args,(char*)0,help)); 20 PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD,&size)); 21 PetscCheck(size == 1,PETSC_COMM_WORLD,PETSC_ERR_WRONG_MPI_SIZE,"This is a uniprocessor example only!"); 22 PetscCall(MatCreate(PETSC_COMM_WORLD,&C)); 23 PetscCall(MatSetSizes(C,PETSC_DECIDE,PETSC_DECIDE,m*n,m*n)); 24 PetscCall(MatSetFromOptions(C)); 25 PetscCall(MatSetUp(C)); 26 PetscCall(PetscOptionsHasName(NULL,NULL,"-symmetric",&flg)); 27 if (flg) { /* Treat matrix as symmetric only if we set this flag */ 28 PetscCall(MatSetOption(C,MAT_SYMMETRIC,PETSC_TRUE)); 29 PetscCall(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; PetscCall(MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES));} 37 if (i<m-1) {J = Ii + n; PetscCall(MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES));} 38 if (j>0) {J = Ii - 1; PetscCall(MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES));} 39 if (j<n-1) {J = Ii + 1; PetscCall(MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES));} 40 v = 4.0; PetscCall(MatSetValues(C,1,&Ii,1,&Ii,&v,INSERT_VALUES)); 41 } 42 } 43 PetscCall(MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY)); 44 PetscCall(MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY)); 45 PetscCall(MatGetOrdering(C,MATORDERINGRCM,&perm,&iperm)); 46 PetscCall(MatView(C,PETSC_VIEWER_STDOUT_WORLD)); 47 PetscCall(ISView(perm,PETSC_VIEWER_STDOUT_SELF)); 48 PetscCall(VecCreateSeq(PETSC_COMM_SELF,m*n,&u)); 49 PetscCall(VecSet(u,1.0)); 50 PetscCall(VecDuplicate(u,&x)); 51 PetscCall(VecDuplicate(u,&b)); 52 PetscCall(VecDuplicate(u,&y)); 53 PetscCall(MatMult(C,u,b)); 54 PetscCall(VecCopy(b,y)); 55 PetscCall(VecScale(y,2.0)); 56 57 PetscCall(MatNorm(C,NORM_FROBENIUS,&norm)); 58 PetscCall(PetscPrintf(PETSC_COMM_SELF,"Frobenius norm of matrix %g\n",(double)norm)); 59 PetscCall(MatNorm(C,NORM_1,&norm)); 60 PetscCall(PetscPrintf(PETSC_COMM_SELF,"One norm of matrix %g\n",(double)norm)); 61 PetscCall(MatNorm(C,NORM_INFINITY,&norm)); 62 PetscCall(PetscPrintf(PETSC_COMM_SELF,"Infinity norm of matrix %g\n",(double)norm)); 63 64 PetscCall(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 PetscCall(MatLUFactor(C,perm,iperm,&info)); 71 72 /* Test MatSolve */ 73 PetscCall(MatSolve(C,b,x)); 74 PetscCall(VecView(b,PETSC_VIEWER_STDOUT_SELF)); 75 PetscCall(VecView(x,PETSC_VIEWER_STDOUT_SELF)); 76 PetscCall(VecAXPY(x,-1.0,u)); 77 PetscCall(VecNorm(x,NORM_2,&norm)); 78 if (norm > tol) { 79 PetscCall(PetscPrintf(PETSC_COMM_SELF,"MatSolve: Norm of error %g\n",(double)norm)); 80 } 81 82 /* Test MatSolveAdd */ 83 PetscCall(MatSolveAdd(C,b,y,x)); 84 PetscCall(VecAXPY(x,-1.0,y)); 85 PetscCall(VecAXPY(x,-1.0,u)); 86 PetscCall(VecNorm(x,NORM_2,&norm)); 87 if (norm > tol) { 88 PetscCall(PetscPrintf(PETSC_COMM_SELF,"MatSolveAdd(): Norm of error %g\n",(double)norm)); 89 } 90 91 PetscCall(ISDestroy(&perm)); 92 PetscCall(ISDestroy(&iperm)); 93 PetscCall(VecDestroy(&u)); 94 PetscCall(VecDestroy(&y)); 95 PetscCall(VecDestroy(&b)); 96 PetscCall(VecDestroy(&x)); 97 PetscCall(MatDestroy(&C)); 98 PetscCall(PetscFinalize()); 99 return 0; 100 } 101 102 /*TEST 103 104 test: 105 106 TEST*/ 107