PetscErrorCode KSPView_LSQR(KSP ksp,PetscViewer viewer)
{
KSP_LSQR *lsqr = (KSP_LSQR*)ksp->data;
PetscErrorCode ierr;
PetscFunctionBegin;
if (lsqr->se) {
PetscReal rnorm;
ierr = KSPLSQRGetStandardErrorVec(ksp,&lsqr->se);CHKERRQ(ierr);
ierr = VecNorm(lsqr->se,NORM_2,&rnorm);CHKERRQ(ierr);
PetscPrintf(PETSC_COMM_WORLD," Norm of Standard Error %A, Iterations %D\n",rnorm,ksp->its);CHKERRQ(ierr);
}
PetscFunctionReturn(0);
}
PetscErrorCode KSPView_LSQR(KSP ksp,PetscViewer viewer)
{
KSP_LSQR *lsqr = (KSP_LSQR*)ksp->data;
PetscErrorCode ierr;
PetscBool iascii;
PetscFunctionBegin;
ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr);
if (iascii) {
if (lsqr->se) {
PetscReal rnorm;
ierr = KSPLSQRGetStandardErrorVec(ksp,&lsqr->se);CHKERRQ(ierr);
ierr = VecNorm(lsqr->se,NORM_2,&rnorm);CHKERRQ(ierr);
ierr = PetscViewerASCIIPrintf(viewer," Norm of Standard Error %G, Iterations %D\n",rnorm,ksp->its);CHKERRQ(ierr);
}
}
PetscFunctionReturn(0);
}
int main(int argc, char** argv)
{
Mat Q;
Vec v, a, se;
KSP QRsolver;
PC pc;
PetscErrorCode ierr;
ierr = PetscInitialize(&argc, &argv, NULL, NULL);if (ierr) return ierr;
ierr = VecCreate(PETSC_COMM_WORLD, &v);CHKERRQ(ierr);
ierr = MatCreate(PETSC_COMM_WORLD, &Q);CHKERRQ(ierr);
ierr = MatSetType(Q, MATDENSE);CHKERRQ(ierr);
ierr = fill(Q, v);CHKERRQ(ierr);
ierr = MatCreateVecs(Q, &a, NULL);CHKERRQ(ierr);
ierr = KSPCreate(PETSC_COMM_WORLD, &QRsolver);CHKERRQ(ierr);
ierr = KSPGetPC(QRsolver, &pc);CHKERRQ(ierr);
ierr = PCSetType(pc, PCNONE);CHKERRQ(ierr);
ierr = KSPSetType(QRsolver, KSPLSQR);CHKERRQ(ierr);
ierr = KSPSetFromOptions(QRsolver);CHKERRQ(ierr);
ierr = KSPSetOperators(QRsolver, Q, Q);CHKERRQ(ierr);
ierr = MatViewFromOptions(Q, NULL, "-sys_view");CHKERRQ(ierr);
ierr = VecViewFromOptions(a, NULL, "-rhs_view");CHKERRQ(ierr);
ierr = KSPSolve(QRsolver, v, a);CHKERRQ(ierr);
ierr = KSPLSQRGetStandardErrorVec(QRsolver, &se);CHKERRQ(ierr);
if (se) {
ierr = VecViewFromOptions(se, NULL, "-se_view");CHKERRQ(ierr);
}
ierr = KSPDestroy(&QRsolver);CHKERRQ(ierr);
ierr = VecDestroy(&a);CHKERRQ(ierr);
ierr = VecDestroy(&v);CHKERRQ(ierr);
ierr = MatDestroy(&Q);CHKERRQ(ierr);
ierr = PetscFinalize();
return ierr;
}