1c4762a1bSJed Brown 2c4762a1bSJed Brown static char help[] = "Demonstrates the use of fast Richardson for SOR. And\n\ 3c4762a1bSJed Brown also tests the MatSOR() routines. Input parameters are:\n\ 4c4762a1bSJed Brown -n <n> : problem dimension\n\n"; 5c4762a1bSJed Brown 6c4762a1bSJed Brown #include <petscksp.h> 7c4762a1bSJed Brown #include <petscpc.h> 8c4762a1bSJed Brown 9c4762a1bSJed Brown int main(int argc,char **args) 10c4762a1bSJed Brown { 11c4762a1bSJed Brown Mat mat; /* matrix */ 12c4762a1bSJed Brown Vec b,ustar,u; /* vectors (RHS, exact solution, approx solution) */ 13c4762a1bSJed Brown PC pc; /* PC context */ 14c4762a1bSJed Brown KSP ksp; /* KSP context */ 15c4762a1bSJed Brown PetscInt n = 10,i,its,col[3]; 16c4762a1bSJed Brown PetscScalar value[3]; 17c4762a1bSJed Brown KSPType kspname; 18c4762a1bSJed Brown PCType pcname; 19c4762a1bSJed Brown 20*327415f7SBarry Smith PetscFunctionBeginUser; 219566063dSJacob Faibussowitsch PetscCall(PetscInitialize(&argc,&args,(char*)0,help)); 229566063dSJacob Faibussowitsch PetscCall(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL)); 23c4762a1bSJed Brown 24c4762a1bSJed Brown /* Create and initialize vectors */ 259566063dSJacob Faibussowitsch PetscCall(VecCreateSeq(PETSC_COMM_SELF,n,&b)); 269566063dSJacob Faibussowitsch PetscCall(VecCreateSeq(PETSC_COMM_SELF,n,&ustar)); 279566063dSJacob Faibussowitsch PetscCall(VecCreateSeq(PETSC_COMM_SELF,n,&u)); 289566063dSJacob Faibussowitsch PetscCall(VecSet(ustar,1.0)); 299566063dSJacob Faibussowitsch PetscCall(VecSet(u,0.0)); 30c4762a1bSJed Brown 31c4762a1bSJed Brown /* Create and assemble matrix */ 329566063dSJacob Faibussowitsch PetscCall(MatCreate(PETSC_COMM_SELF,&mat)); 339566063dSJacob Faibussowitsch PetscCall(MatSetType(mat,MATSEQAIJ)); 349566063dSJacob Faibussowitsch PetscCall(MatSetSizes(mat,n,n,n,n)); 359566063dSJacob Faibussowitsch PetscCall(MatSetFromOptions(mat)); 369566063dSJacob Faibussowitsch PetscCall(MatSeqAIJSetPreallocation(mat,3,NULL)); 379566063dSJacob Faibussowitsch PetscCall(MatSeqBAIJSetPreallocation(mat,1,3,NULL)); 389566063dSJacob Faibussowitsch PetscCall(MatSeqSBAIJSetPreallocation(mat,1,3,NULL)); 399566063dSJacob Faibussowitsch PetscCall(MatSeqSELLSetPreallocation(mat,3,NULL)); 40c4762a1bSJed Brown value[0] = -1.0; value[1] = 2.0; value[2] = -1.0; 41c4762a1bSJed Brown for (i=1; i<n-1; i++) { 42c4762a1bSJed Brown col[0] = i-1; col[1] = i; col[2] = i+1; 439566063dSJacob Faibussowitsch PetscCall(MatSetValues(mat,1,&i,3,col,value,INSERT_VALUES)); 44c4762a1bSJed Brown } 45c4762a1bSJed Brown i = n - 1; col[0] = n - 2; col[1] = n - 1; 469566063dSJacob Faibussowitsch PetscCall(MatSetValues(mat,1,&i,2,col,value,INSERT_VALUES)); 47c4762a1bSJed Brown i = 0; col[0] = 0; col[1] = 1; value[0] = 2.0; value[1] = -1.0; 489566063dSJacob Faibussowitsch PetscCall(MatSetValues(mat,1,&i,2,col,value,INSERT_VALUES)); 499566063dSJacob Faibussowitsch PetscCall(MatAssemblyBegin(mat,MAT_FINAL_ASSEMBLY)); 509566063dSJacob Faibussowitsch PetscCall(MatAssemblyEnd(mat,MAT_FINAL_ASSEMBLY)); 51c4762a1bSJed Brown 52c4762a1bSJed Brown /* Compute right-hand-side vector */ 539566063dSJacob Faibussowitsch PetscCall(MatMult(mat,ustar,b)); 54c4762a1bSJed Brown 55c4762a1bSJed Brown /* Create PC context and set up data structures */ 569566063dSJacob Faibussowitsch PetscCall(PCCreate(PETSC_COMM_WORLD,&pc)); 579566063dSJacob Faibussowitsch PetscCall(PCSetType(pc,PCNONE)); 589566063dSJacob Faibussowitsch PetscCall(PCSetFromOptions(pc)); 599566063dSJacob Faibussowitsch PetscCall(PCSetOperators(pc,mat,mat)); 609566063dSJacob Faibussowitsch PetscCall(PCSetUp(pc)); 61c4762a1bSJed Brown 62c4762a1bSJed Brown /* Create KSP context and set up data structures */ 639566063dSJacob Faibussowitsch PetscCall(KSPCreate(PETSC_COMM_WORLD,&ksp)); 649566063dSJacob Faibussowitsch PetscCall(KSPSetType(ksp,KSPRICHARDSON)); 659566063dSJacob Faibussowitsch PetscCall(KSPSetFromOptions(ksp)); 669566063dSJacob Faibussowitsch PetscCall(PCSetOperators(pc,mat,mat)); 679566063dSJacob Faibussowitsch PetscCall(KSPSetPC(ksp,pc)); 689566063dSJacob Faibussowitsch PetscCall(KSPSetUp(ksp)); 69c4762a1bSJed Brown 70c4762a1bSJed Brown /* Solve the problem */ 719566063dSJacob Faibussowitsch PetscCall(KSPGetType(ksp,&kspname)); 729566063dSJacob Faibussowitsch PetscCall(PCGetType(pc,&pcname)); 739566063dSJacob Faibussowitsch PetscCall(PetscPrintf(PETSC_COMM_SELF,"Running %s with %s preconditioning\n",kspname,pcname)); 749566063dSJacob Faibussowitsch PetscCall(KSPSolve(ksp,b,u)); 759566063dSJacob Faibussowitsch PetscCall(KSPGetIterationNumber(ksp,&its)); 7663a3b9bcSJacob Faibussowitsch PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Number of iterations %" PetscInt_FMT "\n",its)); 77c4762a1bSJed Brown 78c4762a1bSJed Brown /* Free data structures */ 799566063dSJacob Faibussowitsch PetscCall(KSPDestroy(&ksp)); 809566063dSJacob Faibussowitsch PetscCall(VecDestroy(&u)); 819566063dSJacob Faibussowitsch PetscCall(VecDestroy(&ustar)); 829566063dSJacob Faibussowitsch PetscCall(VecDestroy(&b)); 839566063dSJacob Faibussowitsch PetscCall(MatDestroy(&mat)); 849566063dSJacob Faibussowitsch PetscCall(PCDestroy(&pc)); 859566063dSJacob Faibussowitsch PetscCall(PetscFinalize()); 86b122ec5aSJacob Faibussowitsch return 0; 87c4762a1bSJed Brown } 88c4762a1bSJed Brown 89c4762a1bSJed Brown /*TEST 90c4762a1bSJed Brown 91c4762a1bSJed Brown testset: 92c4762a1bSJed Brown args: -ksp_type gmres -ksp_monitor_short -pc_type sor -pc_sor_symmetric 93c4762a1bSJed Brown output_file: output/ex3_1.out 94c4762a1bSJed Brown test: 95c4762a1bSJed Brown suffix: sor_aij 96c4762a1bSJed Brown test: 97c4762a1bSJed Brown suffix: sor_seqbaij 98c4762a1bSJed Brown args: -mat_type seqbaij 99c4762a1bSJed Brown test: 100c4762a1bSJed Brown suffix: sor_seqsbaij 101c4762a1bSJed Brown args: -mat_type seqbaij 102c4762a1bSJed Brown test: 103c4762a1bSJed Brown suffix: sor_seqsell 104c4762a1bSJed Brown args: -mat_type seqsell 105c4762a1bSJed Brown 106c4762a1bSJed Brown TEST*/ 107