1*c4762a1bSJed Brown 2*c4762a1bSJed Brown static char help[] = "Tests relaxation for dense matrices.\n\n"; 3*c4762a1bSJed Brown 4*c4762a1bSJed Brown #include <petscmat.h> 5*c4762a1bSJed Brown 6*c4762a1bSJed Brown int main(int argc,char **args) 7*c4762a1bSJed Brown { 8*c4762a1bSJed Brown Mat C; 9*c4762a1bSJed Brown Vec u,x,b,e; 10*c4762a1bSJed Brown PetscInt i,n = 10,midx[3]; 11*c4762a1bSJed Brown PetscErrorCode ierr; 12*c4762a1bSJed Brown PetscScalar v[3]; 13*c4762a1bSJed Brown PetscReal omega = 1.0,norm; 14*c4762a1bSJed Brown 15*c4762a1bSJed Brown ierr = PetscInitialize(&argc,&args,(char*)0,help);if (ierr) return ierr; 16*c4762a1bSJed Brown ierr = PetscOptionsGetReal(NULL,NULL,"-omega",&omega,NULL);CHKERRQ(ierr); 17*c4762a1bSJed Brown ierr = PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);CHKERRQ(ierr); 18*c4762a1bSJed Brown 19*c4762a1bSJed Brown ierr = MatCreate(PETSC_COMM_SELF,&C);CHKERRQ(ierr); 20*c4762a1bSJed Brown ierr = MatSetSizes(C,n,n,n,n);CHKERRQ(ierr); 21*c4762a1bSJed Brown ierr = MatSetType(C,MATSEQDENSE);CHKERRQ(ierr); 22*c4762a1bSJed Brown ierr = MatSetUp(C);CHKERRQ(ierr); 23*c4762a1bSJed Brown ierr = VecCreateSeq(PETSC_COMM_SELF,n,&b);CHKERRQ(ierr); 24*c4762a1bSJed Brown ierr = VecCreateSeq(PETSC_COMM_SELF,n,&x);CHKERRQ(ierr); 25*c4762a1bSJed Brown ierr = VecCreateSeq(PETSC_COMM_SELF,n,&u);CHKERRQ(ierr); 26*c4762a1bSJed Brown ierr = VecCreateSeq(PETSC_COMM_SELF,n,&e);CHKERRQ(ierr); 27*c4762a1bSJed Brown ierr = VecSet(u,1.0);CHKERRQ(ierr); 28*c4762a1bSJed Brown ierr = VecSet(x,0.0);CHKERRQ(ierr); 29*c4762a1bSJed Brown 30*c4762a1bSJed Brown v[0] = -1.; v[1] = 2.; v[2] = -1.; 31*c4762a1bSJed Brown for (i=1; i<n-1; i++) { 32*c4762a1bSJed Brown midx[0] = i-1; midx[1] = i; midx[2] = i+1; 33*c4762a1bSJed Brown ierr = MatSetValues(C,1,&i,3,midx,v,INSERT_VALUES);CHKERRQ(ierr); 34*c4762a1bSJed Brown } 35*c4762a1bSJed Brown i = 0; midx[0] = 0; midx[1] = 1; 36*c4762a1bSJed Brown v[0] = 2.0; v[1] = -1.; 37*c4762a1bSJed Brown ierr = MatSetValues(C,1,&i,2,midx,v,INSERT_VALUES);CHKERRQ(ierr); 38*c4762a1bSJed Brown i = n-1; midx[0] = n-2; midx[1] = n-1; 39*c4762a1bSJed Brown v[0] = -1.0; v[1] = 2.; 40*c4762a1bSJed Brown ierr = MatSetValues(C,1,&i,2,midx,v,INSERT_VALUES);CHKERRQ(ierr); 41*c4762a1bSJed Brown 42*c4762a1bSJed Brown ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); 43*c4762a1bSJed Brown ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); 44*c4762a1bSJed Brown 45*c4762a1bSJed Brown ierr = MatMult(C,u,b);CHKERRQ(ierr); 46*c4762a1bSJed Brown 47*c4762a1bSJed Brown for (i=0; i<n; i++) { 48*c4762a1bSJed Brown ierr = MatSOR(C,b,omega,SOR_FORWARD_SWEEP,0.0,1,1,x);CHKERRQ(ierr); 49*c4762a1bSJed Brown ierr = VecWAXPY(e,-1.0,x,u);CHKERRQ(ierr); 50*c4762a1bSJed Brown ierr = VecNorm(e,NORM_2,&norm);CHKERRQ(ierr); 51*c4762a1bSJed Brown ierr = PetscPrintf(PETSC_COMM_SELF,"2-norm of error %g\n",(double)norm);CHKERRQ(ierr); 52*c4762a1bSJed Brown } 53*c4762a1bSJed Brown ierr = MatDestroy(&C);CHKERRQ(ierr); 54*c4762a1bSJed Brown ierr = VecDestroy(&x);CHKERRQ(ierr); 55*c4762a1bSJed Brown ierr = VecDestroy(&b);CHKERRQ(ierr); 56*c4762a1bSJed Brown ierr = VecDestroy(&u);CHKERRQ(ierr); 57*c4762a1bSJed Brown ierr = VecDestroy(&e);CHKERRQ(ierr); 58*c4762a1bSJed Brown ierr = PetscFinalize(); 59*c4762a1bSJed Brown return ierr; 60*c4762a1bSJed Brown } 61*c4762a1bSJed Brown 62*c4762a1bSJed Brown /*TEST 63*c4762a1bSJed Brown 64*c4762a1bSJed Brown test: 65*c4762a1bSJed Brown 66*c4762a1bSJed Brown TEST*/ 67