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 ierr = MPI_Comm_size(PETSC_COMM_WORLD,&size);CHKERRQ(ierr); 21 if (size != 1) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_WRONG_MPI_SIZE,"This is a uniprocessor example only!"); 22 ierr = MatCreate(PETSC_COMM_WORLD,&C);CHKERRQ(ierr); 23 ierr = MatSetSizes(C,PETSC_DECIDE,PETSC_DECIDE,m*n,m*n);CHKERRQ(ierr); 24 ierr = MatSetFromOptions(C);CHKERRQ(ierr); 25 ierr = MatSetUp(C);CHKERRQ(ierr); 26 ierr = PetscOptionsHasName(NULL,NULL,"-symmetric",&flg);CHKERRQ(ierr); 27 if (flg) { /* Treat matrix as symmetric only if we set this flag */ 28 ierr = MatSetOption(C,MAT_SYMMETRIC,PETSC_TRUE);CHKERRQ(ierr); 29 ierr = MatSetOption(C,MAT_SYMMETRY_ETERNAL,PETSC_TRUE);CHKERRQ(ierr); 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; ierr = MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);CHKERRQ(ierr);} 37 if (i<m-1) {J = Ii + n; ierr = MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);CHKERRQ(ierr);} 38 if (j>0) {J = Ii - 1; ierr = MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);CHKERRQ(ierr);} 39 if (j<n-1) {J = Ii + 1; ierr = MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);CHKERRQ(ierr);} 40 v = 4.0; ierr = MatSetValues(C,1,&Ii,1,&Ii,&v,INSERT_VALUES);CHKERRQ(ierr); 41 } 42 } 43 ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); 44 ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); 45 ierr = MatGetOrdering(C,MATORDERINGRCM,&perm,&iperm);CHKERRQ(ierr); 46 ierr = MatView(C,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr); 47 ierr = ISView(perm,PETSC_VIEWER_STDOUT_SELF);CHKERRQ(ierr); 48 ierr = VecCreateSeq(PETSC_COMM_SELF,m*n,&u);CHKERRQ(ierr); 49 ierr = VecSet(u,1.0);CHKERRQ(ierr); 50 ierr = VecDuplicate(u,&x);CHKERRQ(ierr); 51 ierr = VecDuplicate(u,&b);CHKERRQ(ierr); 52 ierr = VecDuplicate(u,&y);CHKERRQ(ierr); 53 ierr = MatMult(C,u,b);CHKERRQ(ierr); 54 ierr = VecCopy(b,y);CHKERRQ(ierr); 55 ierr = VecScale(y,2.0);CHKERRQ(ierr); 56 57 ierr = MatNorm(C,NORM_FROBENIUS,&norm);CHKERRQ(ierr); 58 ierr = PetscPrintf(PETSC_COMM_SELF,"Frobenius norm of matrix %g\n",(double)norm);CHKERRQ(ierr); 59 ierr = MatNorm(C,NORM_1,&norm);CHKERRQ(ierr); 60 ierr = PetscPrintf(PETSC_COMM_SELF,"One norm of matrix %g\n",(double)norm);CHKERRQ(ierr); 61 ierr = MatNorm(C,NORM_INFINITY,&norm);CHKERRQ(ierr); 62 ierr = PetscPrintf(PETSC_COMM_SELF,"Infinity norm of matrix %g\n",(double)norm);CHKERRQ(ierr); 63 64 ierr = MatFactorInfoInitialize(&info);CHKERRQ(ierr); 65 info.fill = 2.0; 66 info.dtcol = 0.0; 67 info.zeropivot = 1.e-14; 68 info.pivotinblocks = 1.0; 69 70 ierr = MatLUFactor(C,perm,iperm,&info);CHKERRQ(ierr); 71 72 /* Test MatSolve */ 73 ierr = MatSolve(C,b,x);CHKERRQ(ierr); 74 ierr = VecView(b,PETSC_VIEWER_STDOUT_SELF);CHKERRQ(ierr); 75 ierr = VecView(x,PETSC_VIEWER_STDOUT_SELF);CHKERRQ(ierr); 76 ierr = VecAXPY(x,-1.0,u);CHKERRQ(ierr); 77 ierr = VecNorm(x,NORM_2,&norm);CHKERRQ(ierr); 78 if (norm > tol) { 79 ierr = PetscPrintf(PETSC_COMM_SELF,"MatSolve: Norm of error %g\n",(double)norm);CHKERRQ(ierr); 80 } 81 82 /* Test MatSolveAdd */ 83 ierr = MatSolveAdd(C,b,y,x);CHKERRQ(ierr); 84 ierr = VecAXPY(x,-1.0,y);CHKERRQ(ierr); 85 ierr = VecAXPY(x,-1.0,u);CHKERRQ(ierr); 86 ierr = VecNorm(x,NORM_2,&norm);CHKERRQ(ierr); 87 if (norm > tol) { 88 ierr = PetscPrintf(PETSC_COMM_SELF,"MatSolveAdd(): Norm of error %g\n",(double)norm);CHKERRQ(ierr); 89 } 90 91 ierr = ISDestroy(&perm);CHKERRQ(ierr); 92 ierr = ISDestroy(&iperm);CHKERRQ(ierr); 93 ierr = VecDestroy(&u);CHKERRQ(ierr); 94 ierr = VecDestroy(&y);CHKERRQ(ierr); 95 ierr = VecDestroy(&b);CHKERRQ(ierr); 96 ierr = VecDestroy(&x);CHKERRQ(ierr); 97 ierr = MatDestroy(&C);CHKERRQ(ierr); 98 ierr = PetscFinalize(); 99 return ierr; 100 } 101 102 103 /*TEST 104 105 test: 106 107 TEST*/ 108