int main(int argc,char **argv)
{
KSP ksp;
DM da;
UserContext user;
const char *bcTypes[2] = {"dirichlet","neumann"};
PetscErrorCode ierr;
PetscInt bc;
Vec b,x;
PetscInitialize(&argc,&argv,(char *)0,help);
ierr = KSPCreate(PETSC_COMM_WORLD,&ksp);
CHKERRQ(ierr);
ierr = DMDACreate2d(PETSC_COMM_WORLD, DMDA_BOUNDARY_NONE, DMDA_BOUNDARY_NONE,DMDA_STENCIL_STAR,-3,-3,PETSC_DECIDE,PETSC_DECIDE,1,1,0,0,&da);
CHKERRQ(ierr);
ierr = DMDASetUniformCoordinates(da,0,1,0,1,0,0);
CHKERRQ(ierr);
ierr = DMDASetFieldName(da,0,"Pressure");
CHKERRQ(ierr);
ierr = PetscOptionsBegin(PETSC_COMM_WORLD, "", "Options for the inhomogeneous Poisson equation", "DMqq");
user.rho = 1.0;
ierr = PetscOptionsReal("-rho", "The conductivity", "ex29.c", user.rho, &user.rho, PETSC_NULL);
CHKERRQ(ierr);
user.nu = 0.1;
ierr = PetscOptionsReal("-nu", "The width of the Gaussian source", "ex29.c", user.nu, &user.nu, PETSC_NULL);
CHKERRQ(ierr);
bc = (PetscInt)DIRICHLET;
ierr = PetscOptionsEList("-bc_type","Type of boundary condition","ex29.c",bcTypes,2,bcTypes[0],&bc,PETSC_NULL);
CHKERRQ(ierr);
user.bcType = (BCType)bc;
ierr = PetscOptionsEnd();
ierr = KSPSetComputeRHS(ksp,ComputeRHS,&user);
CHKERRQ(ierr);
ierr = KSPSetComputeOperators(ksp,ComputeMatrix,&user);
CHKERRQ(ierr);
ierr = KSPSetDM(ksp,da);
CHKERRQ(ierr);
ierr = KSPSetFromOptions(ksp);
CHKERRQ(ierr);
ierr = KSPSetUp(ksp);
CHKERRQ(ierr);
ierr = KSPSolve(ksp,PETSC_NULL,PETSC_NULL);
CHKERRQ(ierr);
ierr = KSPGetSolution(ksp,&x);
CHKERRQ(ierr);
ierr = KSPGetRhs(ksp,&b);
CHKERRQ(ierr);
ierr = DMDestroy(&da);
CHKERRQ(ierr);
ierr = KSPDestroy(&ksp);
CHKERRQ(ierr);
ierr = PetscFinalize();
return 0;
}
int main(int argc,char **argv)
{
PetscErrorCode ierr;
KSP ksp;
PetscReal norm;
DM da;
Vec x,b,r;
Mat A;
PetscInitialize(&argc,&argv,(char *)0,help);
ierr = KSPCreate(PETSC_COMM_WORLD,&ksp);
CHKERRQ(ierr);
ierr = DMDACreate3d(PETSC_COMM_WORLD,DMDA_BOUNDARY_NONE,DMDA_BOUNDARY_NONE,DMDA_BOUNDARY_NONE,DMDA_STENCIL_STAR,-7,-7,-7,PETSC_DECIDE,PETSC_DECIDE,PETSC_DECIDE,1,1,0,0,0,&da);
CHKERRQ(ierr);
ierr = DMSetInitialGuess(da,ComputeInitialGuess);
CHKERRQ(ierr);
ierr = KSPSetComputeRHS(ksp,ComputeRHS,PETSC_NULL);
CHKERRQ(ierr);
ierr = KSPSetComputeOperators(ksp,ComputeMatrix,PETSC_NULL);
CHKERRQ(ierr);
ierr = KSPSetDM(ksp,da);
CHKERRQ(ierr);
ierr = DMDestroy(&da);
CHKERRQ(ierr);
ierr = KSPSetFromOptions(ksp);
CHKERRQ(ierr);
ierr = KSPSolve(ksp,PETSC_NULL,PETSC_NULL);
CHKERRQ(ierr);
ierr = KSPGetSolution(ksp,&x);
CHKERRQ(ierr);
ierr = KSPGetRhs(ksp,&b);
CHKERRQ(ierr);
ierr = VecDuplicate(b,&r);
CHKERRQ(ierr);
ierr = KSPGetOperators(ksp,&A,PETSC_NULL,PETSC_NULL);
CHKERRQ(ierr);
ierr = MatMult(A,x,r);
CHKERRQ(ierr);
ierr = VecAXPY(r,-1.0,b);
CHKERRQ(ierr);
ierr = VecNorm(r,NORM_2,&norm);
CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"Residual norm %G\n",norm);
CHKERRQ(ierr);
ierr = VecDestroy(&r);
CHKERRQ(ierr);
ierr = KSPDestroy(&ksp);
CHKERRQ(ierr);
ierr = PetscFinalize();
return 0;
}
/*@C
KSPMonitorDynamicTolerance - Recompute the inner tolerance in every
outer iteration in an adaptive way.
Collective on KSP
Input Parameters:
+ ksp - iterative context
. n - iteration number (not used)
. fnorm - the current residual norm
. dummy - some context as a C struct. fields:
coef: a scaling coefficient. default 1.0. can be passed through
-sub_ksp_dynamic_tolerance_param
bnrm: norm of the right-hand side. store it to avoid repeated calculation
Notes:
This may be useful for a flexibly preconditioner Krylov method to
control the accuracy of the inner solves needed to gaurantee the
convergence of the outer iterations.
Level: advanced
.keywords: KSP, inner tolerance
.seealso: KSPMonitorDynamicToleranceDestroy()
@*/
PetscErrorCode KSPMonitorDynamicTolerance(KSP ksp,PetscInt its,PetscReal fnorm,void *dummy)
{
PetscErrorCode ierr;
PC pc;
PetscReal outer_rtol, outer_abstol, outer_dtol, inner_rtol;
PetscInt outer_maxits,nksp,first,i;
KSPDynTolCtx *scale = (KSPDynTolCtx*)dummy;
KSP kspinner = NULL, *subksp = NULL;
PetscFunctionBegin;
ierr = KSPGetPC(ksp, &pc);
CHKERRQ(ierr);
/* compute inner_rtol */
if (scale->bnrm < 0.0) {
Vec b;
ierr = KSPGetRhs(ksp, &b);
CHKERRQ(ierr);
ierr = VecNorm(b, NORM_2, &(scale->bnrm));
CHKERRQ(ierr);
}
ierr = KSPGetTolerances(ksp, &outer_rtol, &outer_abstol, &outer_dtol, &outer_maxits);
CHKERRQ(ierr);
inner_rtol = PetscMin(scale->coef * scale->bnrm * outer_rtol / fnorm, 0.999);
/*ierr = PetscPrintf(PETSC_COMM_WORLD, " Inner rtol = %g\n", (double)inner_rtol);CHKERRQ(ierr);*/
/* if pc is ksp */
ierr = PCKSPGetKSP(pc, &kspinner);
CHKERRQ(ierr);
if (kspinner) {
ierr = KSPSetTolerances(kspinner, inner_rtol, outer_abstol, outer_dtol, outer_maxits);
CHKERRQ(ierr);
PetscFunctionReturn(0);
}
/* if pc is bjacobi */
ierr = PCBJacobiGetSubKSP(pc, &nksp, &first, &subksp);
CHKERRQ(ierr);
if (subksp) {
for (i=0; i<nksp; i++) {
ierr = KSPSetTolerances(subksp[i], inner_rtol, outer_abstol, outer_dtol, outer_maxits);
CHKERRQ(ierr);
}
PetscFunctionReturn(0);
}
/* todo: dynamic tolerance may apply to other types of pc too */
PetscFunctionReturn(0);
}
int main(int argc,char **argv)
{
PetscErrorCode ierr;
KSP ksp;
DM da;
AppCtx user;
Mat A;
Vec b,b2;
Vec x;
PetscReal nrm;
PetscInitialize(&argc,&argv,(char*)0,help);
user.k = 1;
user.e = .99;
ierr = PetscOptionsGetInt(0,"-k",&user.k,0);CHKERRQ(ierr);
ierr = PetscOptionsGetScalar(0,"-e",&user.e,0);CHKERRQ(ierr);
ierr = KSPCreate(PETSC_COMM_WORLD,&ksp);CHKERRQ(ierr);
ierr = DMDACreate1d(PETSC_COMM_WORLD,DM_BOUNDARY_NONE,-3,1,1,0,&da);CHKERRQ(ierr);
ierr = KSPSetDM(ksp,da);CHKERRQ(ierr);
ierr = KSPSetComputeRHS(ksp,ComputeRHS,&user);CHKERRQ(ierr);
ierr = KSPSetComputeOperators(ksp,ComputeMatrix,&user);CHKERRQ(ierr);
ierr = KSPSetFromOptions(ksp);CHKERRQ(ierr);
ierr = KSPSolve(ksp,NULL,NULL);CHKERRQ(ierr);
ierr = KSPGetOperators(ksp,&A,NULL);CHKERRQ(ierr);
ierr = KSPGetSolution(ksp,&x);CHKERRQ(ierr);
ierr = KSPGetRhs(ksp,&b);CHKERRQ(ierr);
ierr = VecDuplicate(b,&b2);CHKERRQ(ierr);
ierr = MatMult(A,x,b2);CHKERRQ(ierr);
ierr = VecAXPY(b2,-1.0,b);CHKERRQ(ierr);
ierr = VecNorm(b2,NORM_MAX,&nrm);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"Residual norm %g\n",(double)nrm);CHKERRQ(ierr);
ierr = VecDestroy(&b2);CHKERRQ(ierr);
ierr = KSPDestroy(&ksp);CHKERRQ(ierr);
ierr = DMDestroy(&da);CHKERRQ(ierr);
ierr = PetscFinalize();
return 0;
}
int main(int argc,char **argv)
{
KSP ksp;
DM da;
PetscReal norm;
PetscErrorCode ierr;
PetscInt i,j,k,mx,my,mz,xm,ym,zm,xs,ys,zs;
PetscScalar Hx,Hy,Hz;
PetscScalar ***array;
Vec x,b,r;
Mat J;
PetscInitialize(&argc,&argv,(char*)0,help);
ierr = KSPCreate(PETSC_COMM_WORLD,&ksp);CHKERRQ(ierr);
ierr = DMDACreate3d(PETSC_COMM_WORLD,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DMDA_STENCIL_STAR,-12,-12,-12,PETSC_DECIDE,PETSC_DECIDE,PETSC_DECIDE,1,1,0,0,0,&da);CHKERRQ(ierr);
ierr = DMDASetInterpolationType(da, DMDA_Q0);CHKERRQ(ierr);
ierr = KSPSetDM(ksp,da);CHKERRQ(ierr);
ierr = KSPSetComputeRHS(ksp,ComputeRHS,NULL);CHKERRQ(ierr);
ierr = KSPSetComputeOperators(ksp,ComputeMatrix,NULL);CHKERRQ(ierr);
ierr = KSPSetFromOptions(ksp);CHKERRQ(ierr);
ierr = KSPSolve(ksp,NULL,NULL);CHKERRQ(ierr);
ierr = KSPGetSolution(ksp,&x);CHKERRQ(ierr);
ierr = KSPGetRhs(ksp,&b);CHKERRQ(ierr);
ierr = KSPGetOperators(ksp,NULL,&J);CHKERRQ(ierr);
ierr = VecDuplicate(b,&r);CHKERRQ(ierr);
ierr = MatMult(J,x,r);CHKERRQ(ierr);
ierr = VecAXPY(r,-1.0,b);CHKERRQ(ierr);
ierr = VecNorm(r,NORM_2,&norm);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"Residual norm %g\n",(double)norm);CHKERRQ(ierr);
ierr = DMDAGetInfo(da, 0, &mx, &my, &mz, 0,0,0,0,0,0,0,0,0);CHKERRQ(ierr);
Hx = 1.0 / (PetscReal)(mx);
Hy = 1.0 / (PetscReal)(my);
Hz = 1.0 / (PetscReal)(mz);
ierr = DMDAGetCorners(da,&xs,&ys,&zs,&xm,&ym,&zm);CHKERRQ(ierr);
ierr = DMDAVecGetArray(da, x, &array);CHKERRQ(ierr);
for (k=zs; k<zs+zm; k++) {
for (j=ys; j<ys+ym; j++) {
for (i=xs; i<xs+xm; i++) {
array[k][j][i] -=
PetscCosScalar(2*PETSC_PI*(((PetscReal)i+0.5)*Hx))*
PetscCosScalar(2*PETSC_PI*(((PetscReal)j+0.5)*Hy))*
PetscCosScalar(2*PETSC_PI*(((PetscReal)k+0.5)*Hz));
}
}
}
ierr = DMDAVecRestoreArray(da, x, &array);CHKERRQ(ierr);
ierr = VecAssemblyBegin(x);CHKERRQ(ierr);
ierr = VecAssemblyEnd(x);CHKERRQ(ierr);
ierr = VecNorm(x,NORM_INFINITY,&norm);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"Error norm %g\n",(double)norm);CHKERRQ(ierr);
ierr = VecNorm(x,NORM_1,&norm);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"Error norm %g\n",(double)(norm/((PetscReal)(mx)*(PetscReal)(my)*(PetscReal)(mz))));CHKERRQ(ierr);
ierr = VecNorm(x,NORM_2,&norm);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"Error norm %g\n",(double)(norm/((PetscReal)(mx)*(PetscReal)(my)*(PetscReal)(mz))));CHKERRQ(ierr);
ierr = VecDestroy(&r);CHKERRQ(ierr);
ierr = KSPDestroy(&ksp);CHKERRQ(ierr);
ierr = DMDestroy(&da);CHKERRQ(ierr);
ierr = PetscFinalize();
return 0;
}
int main(int argc,char **argv)
{
KSP ksp;
DM da;
UserContext user;
PetscReal norm;
const char *bcTypes[2] = {"dirichlet","neumann"};
PetscErrorCode ierr;
PetscInt bc;
PetscInt i,j,k,mx,my,mz,xm,ym,zm,xs,ys,zs;
PetscScalar Hx,Hy,Hz;
PetscScalar ***array;
Vec x,b,r;
Mat J;
PetscInitialize(&argc,&argv,(char *)0,help);
ierr = KSPCreate(PETSC_COMM_WORLD,&ksp);CHKERRQ(ierr);
ierr = DMDACreate3d(PETSC_COMM_WORLD,DMDA_BOUNDARY_NONE,DMDA_BOUNDARY_NONE,DMDA_BOUNDARY_NONE,DMDA_STENCIL_STAR,12,12,12,PETSC_DECIDE,PETSC_DECIDE,PETSC_DECIDE,1,1,0,0,0,&da);CHKERRQ(ierr);
ierr = DMDASetInterpolationType(da, DMDA_Q0);CHKERRQ(ierr);
ierr = KSPSetDM(ksp,da);CHKERRQ(ierr);
ierr = PetscOptionsBegin(PETSC_COMM_WORLD, "", "Options for the inhomogeneous Poisson equation", "DM");
bc = (PetscInt)NEUMANN;
ierr = PetscOptionsEList("-bc_type","Type of boundary condition","ex34.c",bcTypes,2,bcTypes[0],&bc,PETSC_NULL);CHKERRQ(ierr);
user.bcType = (BCType)bc;
ierr = PetscOptionsEnd();
ierr = KSPSetComputeRHS(ksp,ComputeRHS,&user);CHKERRQ(ierr);
ierr = KSPSetComputeOperators(ksp,ComputeMatrix,&user);CHKERRQ(ierr);
ierr = KSPSetFromOptions(ksp);CHKERRQ(ierr);
ierr = KSPSolve(ksp,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr);
ierr = KSPGetSolution(ksp,&x);CHKERRQ(ierr);
ierr = KSPGetRhs(ksp,&b);CHKERRQ(ierr);
ierr = KSPGetOperators(ksp,PETSC_NULL,&J,PETSC_NULL);CHKERRQ(ierr);
ierr = VecDuplicate(b,&r);CHKERRQ(ierr);
ierr = MatMult(J,x,r);CHKERRQ(ierr);
ierr = VecAXPY(r,-1.0,b);CHKERRQ(ierr);
ierr = VecNorm(r,NORM_2,&norm);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"Residual norm %G\n",norm);CHKERRQ(ierr);
ierr = DMDAGetInfo(da, 0, &mx, &my, &mz, 0,0,0,0,0,0,0,0,0);CHKERRQ(ierr);
Hx = 1.0 / (PetscReal)(mx);
Hy = 1.0 / (PetscReal)(my);
Hz = 1.0 / (PetscReal)(mz);
ierr = DMDAGetCorners(da,&xs,&ys,&zs,&xm,&ym,&zm);CHKERRQ(ierr);
ierr = DMDAVecGetArray(da, x, &array);CHKERRQ(ierr);
for (k=zs; k<zs+zm; k++){
for (j=ys; j<ys+ym; j++){
for(i=xs; i<xs+xm; i++){
array[k][j][i] -=
PetscCosScalar(2*PETSC_PI*(((PetscReal)i+0.5)*Hx))*
PetscCosScalar(2*PETSC_PI*(((PetscReal)j+0.5)*Hy))*
PetscCosScalar(2*PETSC_PI*(((PetscReal)k+0.5)*Hz));
}
}
}
ierr = DMDAVecRestoreArray(da, x, &array);CHKERRQ(ierr);
ierr = VecAssemblyBegin(x);CHKERRQ(ierr);
ierr = VecAssemblyEnd(x);CHKERRQ(ierr);
ierr = VecNorm(x,NORM_INFINITY,&norm);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"Error norm %g\n",norm);CHKERRQ(ierr);
ierr = VecNorm(x,NORM_1,&norm);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"Error norm %g\n",norm/((PetscReal)(mx)*(PetscReal)(my)*(PetscReal)(mz)));CHKERRQ(ierr);
ierr = VecNorm(x,NORM_2,&norm);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"Error norm %g\n",norm/((PetscReal)(mx)*(PetscReal)(my)*(PetscReal)(mz)));CHKERRQ(ierr);
ierr = VecDestroy(&r);CHKERRQ(ierr);
ierr = KSPDestroy(&ksp);CHKERRQ(ierr);
ierr = DMDestroy(&da);CHKERRQ(ierr);
ierr = PetscFinalize();
return 0;
}
