static PetscErrorCode KSPSolve_PREONLY(KSP ksp)
{
PetscErrorCode ierr;
PetscTruth diagonalscale;
PetscFunctionBegin;
ierr = PCDiagonalScale(ksp->pc,&diagonalscale);CHKERRQ(ierr);
if (diagonalscale) SETERRQ1(PETSC_ERR_SUP,"Krylov method %s does not support diagonal scaling",((PetscObject)ksp)->type_name);
if (!ksp->guess_zero) {
SETERRQ(PETSC_ERR_USER,"Running KSP of preonly doesn't make sense with nonzero initial guess\n\
you probably want a KSP type of Richardson");
}
PetscErrorCode KSPSolve_CG(KSP ksp)
{
PetscErrorCode ierr;
PetscInt i,stored_max_it,eigs;
PetscScalar dpi = 0.0,a = 1.0,beta,betaold = 1.0,b = 0,*e = 0,*d = 0,delta,dpiold;
PetscReal dp = 0.0;
Vec X,B,Z,R,P,S,W;
KSP_CG *cg;
Mat Amat,Pmat;
MatStructure pflag;
PetscTruth diagonalscale;
PetscFunctionBegin;
ierr = PCDiagonalScale(ksp->pc,&diagonalscale);CHKERRQ(ierr);
if (diagonalscale) SETERRQ1(PETSC_ERR_SUP,"Krylov method %s does not support diagonal scaling",((PetscObject)ksp)->type_name);
cg = (KSP_CG*)ksp->data;
eigs = ksp->calc_sings;
stored_max_it = ksp->max_it;
X = ksp->vec_sol;
B = ksp->vec_rhs;
R = ksp->work[0];
Z = ksp->work[1];
P = ksp->work[2];
if (cg->singlereduction) {
S = ksp->work[3];
W = ksp->work[4];
} else {
S = 0; /* unused */
W = Z;
}
#if !defined(PETSC_USE_COMPLEX)
#define VecXDot(x,y,a) VecDot(x,y,a)
#else
#define VecXDot(x,y,a) (((cg->type) == (KSP_CG_HERMITIAN)) ? VecDot(x,y,a) : VecTDot(x,y,a))
#endif
if (eigs) {e = cg->e; d = cg->d; e[0] = 0.0; }
ierr = PCGetOperators(ksp->pc,&Amat,&Pmat,&pflag);CHKERRQ(ierr);
ksp->its = 0;
if (!ksp->guess_zero) {
ierr = KSP_MatMult(ksp,Amat,X,R);CHKERRQ(ierr); /* r <- b - Ax */
ierr = VecAYPX(R,-1.0,B);CHKERRQ(ierr);
} else {
ierr = VecCopy(B,R);CHKERRQ(ierr); /* r <- b (x is 0) */
}
if (ksp->normtype == KSP_NORM_PRECONDITIONED) {
ierr = KSP_PCApply(ksp,R,Z);CHKERRQ(ierr); /* z <- Br */
ierr = VecNorm(Z,NORM_2,&dp);CHKERRQ(ierr); /* dp <- z'*z = e'*A'*B'*B*A'*e' */
} else if (ksp->normtype == KSP_NORM_UNPRECONDITIONED) {
ierr = VecNorm(R,NORM_2,&dp);CHKERRQ(ierr); /* dp <- r'*r = e'*A'*A*e */
} else if (ksp->normtype == KSP_NORM_NATURAL) {
ierr = KSP_PCApply(ksp,R,Z);CHKERRQ(ierr); /* z <- Br */
if (cg->singlereduction) {
ierr = KSP_MatMult(ksp,Amat,Z,S);CHKERRQ(ierr);
ierr = VecXDot(Z,S,&delta);CHKERRQ(ierr);
}
ierr = VecXDot(Z,R,&beta);CHKERRQ(ierr); /* beta <- z'*r */
if PetscIsInfOrNanScalar(beta) SETERRQ(PETSC_ERR_FP,"Infinite or not-a-number generated in dot product");
dp = sqrt(PetscAbsScalar(beta)); /* dp <- r'*z = r'*B*r = e'*A'*B*A*e */
} else dp = 0.0;
static PetscErrorCode KSPSolve_LSQR(KSP ksp)
{
PetscErrorCode ierr;
PetscInt i,size1,size2;
PetscScalar rho,rhobar,phi,phibar,theta,c,s,tmp,tau,alphac;
PetscReal beta,alpha,rnorm;
Vec X,B,V,V1,U,U1,TMP,W,W2,SE,Z = PETSC_NULL;
Mat Amat,Pmat;
MatStructure pflag;
KSP_LSQR *lsqr = (KSP_LSQR*)ksp->data;
PetscTruth diagonalscale,nopreconditioner;
PetscFunctionBegin;
ierr = PCDiagonalScale(ksp->pc,&diagonalscale);CHKERRQ(ierr);
if (diagonalscale) SETERRQ1(PETSC_ERR_SUP,"Krylov method %s does not support diagonal scaling",((PetscObject)ksp)->type_name);
ierr = PCGetOperators(ksp->pc,&Amat,&Pmat,&pflag);CHKERRQ(ierr);
ierr = PetscTypeCompare((PetscObject)ksp->pc,PCNONE,&nopreconditioner);CHKERRQ(ierr);
/* nopreconditioner =PETSC_FALSE; */
/* Calculate norm of right hand side */
ierr = VecNorm(ksp->vec_rhs,NORM_2,&lsqr->rhs_norm);CHKERRQ(ierr);
/* Calculate norm of matrix*/
ierr = MatNorm( Amat, NORM_FROBENIUS, &lsqr->anorm);CHKERRQ(ierr);
/* vectors of length m, where system size is mxn */
B = ksp->vec_rhs;
U = lsqr->vwork_m[0];
U1 = lsqr->vwork_m[1];
/* vectors of length n */
X = ksp->vec_sol;
W = lsqr->vwork_n[0];
V = lsqr->vwork_n[1];
V1 = lsqr->vwork_n[2];
W2 = lsqr->vwork_n[3];
if (!nopreconditioner) {
Z = lsqr->vwork_n[4];
}
/* standard error vector */
SE = lsqr->se;
if (SE){
ierr = VecGetSize(SE,&size1);CHKERRQ(ierr);
ierr = VecGetSize(X ,&size2);CHKERRQ(ierr);
if (size1 != size2) SETERRQ2(PETSC_ERR_ARG_SIZ,"Standard error vector (size %d) does not match solution vector (size %d)",size1,size2);
ierr = VecSet(SE,0.0);CHKERRQ(ierr);
}
/* Compute initial residual, temporarily use work vector u */
if (!ksp->guess_zero) {
ierr = KSP_MatMult(ksp,Amat,X,U);CHKERRQ(ierr); /* u <- b - Ax */
ierr = VecAYPX(U,-1.0,B);CHKERRQ(ierr);
} else {
ierr = VecCopy(B,U);CHKERRQ(ierr); /* u <- b (x is 0) */
}
/* Test for nothing to do */
ierr = VecNorm(U,NORM_2,&rnorm);CHKERRQ(ierr);
ierr = PetscObjectTakeAccess(ksp);CHKERRQ(ierr);
ksp->its = 0;
ksp->rnorm = rnorm;
ierr = PetscObjectGrantAccess(ksp);CHKERRQ(ierr);
KSPLogResidualHistory(ksp,rnorm);
KSPMonitor(ksp,0,rnorm);
ierr = (*ksp->converged)(ksp,0,rnorm,&ksp->reason,ksp->cnvP);CHKERRQ(ierr);
if (ksp->reason) PetscFunctionReturn(0);
ierr = VecCopy(B,U);CHKERRQ(ierr);
ierr = VecNorm(U,NORM_2,&beta);CHKERRQ(ierr);
ierr = VecScale(U,1.0/beta);CHKERRQ(ierr);
ierr = KSP_MatMultTranspose(ksp,Amat,U,V); CHKERRQ(ierr);
if (nopreconditioner) {
ierr = VecNorm(V,NORM_2,&alpha); CHKERRQ(ierr);
} else {
ierr = PCApply(ksp->pc,V,Z);CHKERRQ(ierr);
ierr = VecDot(V,Z,&alphac);CHKERRQ(ierr);
if (PetscRealPart(alphac) <= 0.0) {
ksp->reason = KSP_DIVERGED_BREAKDOWN;
PetscFunctionReturn(0);
}
alpha = sqrt(PetscRealPart(alphac));
ierr = VecScale(Z,1.0/alpha); CHKERRQ(ierr);
}
ierr = VecScale(V,1.0/alpha);CHKERRQ(ierr);
if (nopreconditioner){
ierr = VecCopy(V,W);CHKERRQ(ierr);
} else {
ierr = VecCopy(Z,W);CHKERRQ(ierr);
}
ierr = VecSet(X,0.0);CHKERRQ(ierr);
lsqr->arnorm = alpha * beta;
phibar = beta;
rhobar = alpha;
tau = -beta;
i = 0;
do {
if (nopreconditioner) {
ierr = KSP_MatMult(ksp,Amat,V,U1);CHKERRQ(ierr);
} else {
ierr = KSP_MatMult(ksp,Amat,Z,U1);CHKERRQ(ierr);
}
ierr = VecAXPY(U1,-alpha,U);CHKERRQ(ierr);
ierr = VecNorm(U1,NORM_2,&beta);CHKERRQ(ierr);
if (beta == 0.0){
ksp->reason = KSP_DIVERGED_BREAKDOWN;
break;
}
ierr = VecScale(U1,1.0/beta);CHKERRQ(ierr);
ierr = KSP_MatMultTranspose(ksp,Amat,U1,V1);CHKERRQ(ierr);
ierr = VecAXPY(V1,-beta,V);CHKERRQ(ierr);
if (nopreconditioner) {
ierr = VecNorm(V1,NORM_2,&alpha); CHKERRQ(ierr);
} else {
ierr = PCApply(ksp->pc,V1,Z);CHKERRQ(ierr);
ierr = VecDot(V1,Z,&alphac);CHKERRQ(ierr);
if (PetscRealPart(alphac) <= 0.0) {
ksp->reason = KSP_DIVERGED_BREAKDOWN;
break;
}
alpha = sqrt(PetscRealPart(alphac));
ierr = VecScale(Z,1.0/alpha);CHKERRQ(ierr);
}
ierr = VecScale(V1,1.0/alpha);CHKERRQ(ierr);
rho = PetscSqrtScalar(rhobar*rhobar + beta*beta);
c = rhobar / rho;
s = beta / rho;
theta = s * alpha;
rhobar = - c * alpha;
phi = c * phibar;
phibar = s * phibar;
tau = s * phi;
ierr = VecAXPY(X,phi/rho,W);CHKERRQ(ierr); /* x <- x + (phi/rho) w */
if (SE) {
ierr = VecCopy(W,W2);CHKERRQ(ierr);
ierr = VecSquare(W2);CHKERRQ(ierr);
ierr = VecScale(W2,1.0/(rho*rho));CHKERRQ(ierr);
ierr = VecAXPY(SE, 1.0, W2);CHKERRQ(ierr); /* SE <- SE + (w^2/rho^2) */
}
if (nopreconditioner) {
ierr = VecAYPX(W,-theta/rho,V1);CHKERRQ(ierr); /* w <- v - (theta/rho) w */
} else {
ierr = VecAYPX(W,-theta/rho,Z);CHKERRQ(ierr); /* w <- z - (theta/rho) w */
}
lsqr->arnorm = alpha*PetscAbsScalar(tau);
rnorm = PetscRealPart(phibar);
ierr = PetscObjectTakeAccess(ksp);CHKERRQ(ierr);
ksp->its++;
ksp->rnorm = rnorm;
ierr = PetscObjectGrantAccess(ksp);CHKERRQ(ierr);
KSPLogResidualHistory(ksp,rnorm);
KSPMonitor(ksp,i+1,rnorm);
ierr = (*ksp->converged)(ksp,i+1,rnorm,&ksp->reason,ksp->cnvP);CHKERRQ(ierr);
if (ksp->reason) break;
SWAP(U1,U,TMP);
SWAP(V1,V,TMP);
i++;
} while (i<ksp->max_it);
if (i >= ksp->max_it && !ksp->reason) {
ksp->reason = KSP_DIVERGED_ITS;
}
/* Finish off the standard error estimates */
if (SE) {
tmp = 1.0;
ierr = MatGetSize(Amat,&size1,&size2);CHKERRQ(ierr);
if ( size1 > size2 ) tmp = size1 - size2;
tmp = rnorm / PetscSqrtScalar(tmp);
ierr = VecSqrt(SE);CHKERRQ(ierr);
ierr = VecScale(SE,tmp);CHKERRQ(ierr);
}
PetscFunctionReturn(0);
}
PetscErrorCode KSPSolve_Chebychev(KSP ksp)
{
PetscErrorCode ierr;
PetscInt k,kp1,km1,maxit,ktmp,i;
PetscScalar alpha,omegaprod,mu,omega,Gamma,c[3],scale;
PetscReal rnorm = 0.0;
Vec x,b,p[3],r;
KSP_Chebychev *chebychevP = (KSP_Chebychev*)ksp->data;
Mat Amat,Pmat;
MatStructure pflag;
PetscTruth diagonalscale;
PetscFunctionBegin;
if (ksp->normtype == KSP_NORM_NATURAL) SETERRQ(PETSC_ERR_SUP,"Cannot use natural residual norm with KSPCHEBYCHEV");
ierr = PCDiagonalScale(ksp->pc,&diagonalscale);CHKERRQ(ierr);
if (diagonalscale) SETERRQ1(PETSC_ERR_SUP,"Krylov method %s does not support diagonal scaling",((PetscObject)ksp)->type_name);
ksp->its = 0;
ierr = PCGetOperators(ksp->pc,&Amat,&Pmat,&pflag);CHKERRQ(ierr);
maxit = ksp->max_it;
/* These three point to the three active solutions, we
rotate these three at each solution update */
km1 = 0; k = 1; kp1 = 2;
x = ksp->vec_sol;
b = ksp->vec_rhs;
p[km1] = x;
p[k] = ksp->work[0];
p[kp1] = ksp->work[1];
r = ksp->work[2];
/* use scale*B as our preconditioner */
scale = 2.0/(chebychevP->emax + chebychevP->emin);
/* -alpha <= scale*lambda(B^{-1}A) <= alpha */
alpha = 1.0 - scale*(chebychevP->emin); ;
Gamma = 1.0;
mu = 1.0/alpha;
omegaprod = 2.0/alpha;
c[km1] = 1.0;
c[k] = mu;
if (!ksp->guess_zero) {
ierr = KSP_MatMult(ksp,Amat,x,r);CHKERRQ(ierr); /* r = b - Ax */
ierr = VecAYPX(r,-1.0,b);CHKERRQ(ierr);
} else {
ierr = VecCopy(b,r);CHKERRQ(ierr);
}
ierr = KSP_PCApply(ksp,r,p[k]);CHKERRQ(ierr); /* p[k] = scale B^{-1}r + x */
ierr = VecAYPX(p[k],scale,x);CHKERRQ(ierr);
for (i=0; i<maxit; i++) {
ierr = PetscObjectTakeAccess(ksp);CHKERRQ(ierr);
ksp->its++;
ierr = PetscObjectGrantAccess(ksp);CHKERRQ(ierr);
c[kp1] = 2.0*mu*c[k] - c[km1];
omega = omegaprod*c[k]/c[kp1];
ierr = KSP_MatMult(ksp,Amat,p[k],r);CHKERRQ(ierr); /* r = b - Ap[k] */
ierr = VecAYPX(r,-1.0,b);CHKERRQ(ierr);
ierr = KSP_PCApply(ksp,r,p[kp1]);CHKERRQ(ierr); /* p[kp1] = B^{-1}z */
/* calculate residual norm if requested */
if (ksp->normtype != KSP_NORM_NO) {
if (ksp->normtype == KSP_NORM_UNPRECONDITIONED) {ierr = VecNorm(r,NORM_2,&rnorm);CHKERRQ(ierr);}
else {ierr = VecNorm(p[kp1],NORM_2,&rnorm);CHKERRQ(ierr);}
ierr = PetscObjectTakeAccess(ksp);CHKERRQ(ierr);
ksp->rnorm = rnorm;
ierr = PetscObjectGrantAccess(ksp);CHKERRQ(ierr);
ksp->vec_sol = p[k];
KSPLogResidualHistory(ksp,rnorm);
KSPMonitor(ksp,i,rnorm);
ierr = (*ksp->converged)(ksp,i,rnorm,&ksp->reason,ksp->cnvP);CHKERRQ(ierr);
if (ksp->reason) break;
}
/* y^{k+1} = omega(y^{k} - y^{k-1} + Gamma*r^{k}) + y^{k-1} */
ierr = VecScale(p[kp1],omega*Gamma*scale);CHKERRQ(ierr);
ierr = VecAXPY(p[kp1],1.0-omega,p[km1]);CHKERRQ(ierr);
ierr = VecAXPY(p[kp1],omega,p[k]);CHKERRQ(ierr);
ktmp = km1;
km1 = k;
k = kp1;
kp1 = ktmp;
}
if (!ksp->reason) {
if (ksp->normtype != KSP_NORM_NO) {
ierr = KSP_MatMult(ksp,Amat,p[k],r);CHKERRQ(ierr); /* r = b - Ap[k] */
ierr = VecAYPX(r,-1.0,b);CHKERRQ(ierr);
if (ksp->normtype == KSP_NORM_UNPRECONDITIONED) {
ierr = VecNorm(r,NORM_2,&rnorm);CHKERRQ(ierr);
} else {
ierr = KSP_PCApply(ksp,r,p[kp1]);CHKERRQ(ierr); /* p[kp1] = B^{-1}z */
ierr = VecNorm(p[kp1],NORM_2,&rnorm);CHKERRQ(ierr);
}
ierr = PetscObjectTakeAccess(ksp);CHKERRQ(ierr);
ksp->rnorm = rnorm;
ierr = PetscObjectGrantAccess(ksp);CHKERRQ(ierr);
ksp->vec_sol = p[k];
KSPLogResidualHistory(ksp,rnorm);
KSPMonitor(ksp,i,rnorm);
}
if (ksp->its >= ksp->max_it) {
if (ksp->normtype != KSP_NORM_NO) {
ierr = (*ksp->converged)(ksp,i,rnorm,&ksp->reason,ksp->cnvP);CHKERRQ(ierr);
if (!ksp->reason) ksp->reason = KSP_DIVERGED_ITS;
} else {
ksp->reason = KSP_CONVERGED_ITS;
}
}
}
/* make sure solution is in vector x */
ksp->vec_sol = x;
if (k) {
ierr = VecCopy(p[k],x);CHKERRQ(ierr);
}
PetscFunctionReturn(0);
}
PetscErrorCode KSPSolve_BiCG(KSP ksp)
{
PetscErrorCode ierr;
PetscInt i;
PetscTruth diagonalscale;
PetscScalar dpi,a=1.0,beta,betaold=1.0,b,ma;
PetscReal dp;
Vec X,B,Zl,Zr,Rl,Rr,Pl,Pr;
Mat Amat,Pmat;
MatStructure pflag;
PetscFunctionBegin;
if (ksp->normtype == KSP_NORM_NATURAL) SETERRQ(PETSC_ERR_SUP,"Cannot use natural residual norm with KSPIBCGS");
ierr = PCDiagonalScale(ksp->pc,&diagonalscale);CHKERRQ(ierr);
if (diagonalscale) SETERRQ1(PETSC_ERR_SUP,"Krylov method %s does not support diagonal scaling",((PetscObject)ksp)->type_name);
X = ksp->vec_sol;
B = ksp->vec_rhs;
Rl = ksp->work[0];
Zl = ksp->work[1];
Pl = ksp->work[2];
Rr = ksp->work[3];
Zr = ksp->work[4];
Pr = ksp->work[5];
ierr = PCGetOperators(ksp->pc,&Amat,&Pmat,&pflag);CHKERRQ(ierr);
if (!ksp->guess_zero) {
ierr = KSP_MatMult(ksp,Amat,X,Rr);CHKERRQ(ierr); /* r <- b - Ax */
ierr = VecAYPX(Rr,-1.0,B);CHKERRQ(ierr);
} else {
ierr = VecCopy(B,Rr);CHKERRQ(ierr); /* r <- b (x is 0) */
}
ierr = VecCopy(Rr,Rl);CHKERRQ(ierr);
ierr = KSP_PCApply(ksp,Rr,Zr);CHKERRQ(ierr); /* z <- Br */
ierr = VecConjugate(Rl);CHKERRQ(ierr);
ierr = KSP_PCApplyTranspose(ksp,Rl,Zl);CHKERRQ(ierr);
ierr = VecConjugate(Rl);CHKERRQ(ierr);
ierr = VecConjugate(Zl);CHKERRQ(ierr);
if (ksp->normtype == KSP_NORM_PRECONDITIONED) {
ierr = VecNorm(Zr,NORM_2,&dp);CHKERRQ(ierr); /* dp <- z'*z */
} else {
ierr = VecNorm(Rr,NORM_2,&dp);CHKERRQ(ierr); /* dp <- r'*r */
}
KSPMonitor(ksp,0,dp);
ierr = PetscObjectTakeAccess(ksp);CHKERRQ(ierr);
ksp->its = 0;
ksp->rnorm = dp;
ierr = PetscObjectGrantAccess(ksp);CHKERRQ(ierr);
KSPLogResidualHistory(ksp,dp);
ierr = (*ksp->converged)(ksp,0,dp,&ksp->reason,ksp->cnvP);CHKERRQ(ierr);
if (ksp->reason) PetscFunctionReturn(0);
i = 0;
do {
ierr = VecDot(Zr,Rl,&beta);CHKERRQ(ierr); /* beta <- r'z */
if (!i) {
if (beta == 0.0) {
ksp->reason = KSP_DIVERGED_BREAKDOWN_BICG;
PetscFunctionReturn(0);
}
ierr = VecCopy(Zr,Pr);CHKERRQ(ierr); /* p <- z */
ierr = VecCopy(Zl,Pl);CHKERRQ(ierr);
} else {
b = beta/betaold;
ierr = VecAYPX(Pr,b,Zr);CHKERRQ(ierr); /* p <- z + b* p */
b = PetscConj(b);
ierr = VecAYPX(Pl,b,Zl);CHKERRQ(ierr);
}
betaold = beta;
ierr = KSP_MatMult(ksp,Amat,Pr,Zr);CHKERRQ(ierr); /* z <- Kp */
ierr = VecConjugate(Pl);CHKERRQ(ierr);
ierr = KSP_MatMultTranspose(ksp,Amat,Pl,Zl);CHKERRQ(ierr);
ierr = VecConjugate(Pl);CHKERRQ(ierr);
ierr = VecConjugate(Zl);CHKERRQ(ierr);
ierr = VecDot(Zr,Pl,&dpi);CHKERRQ(ierr); /* dpi <- z'p */
a = beta/dpi; /* a = beta/p'z */
ierr = VecAXPY(X,a,Pr);CHKERRQ(ierr); /* x <- x + ap */
ma = -a;
ierr = VecAXPY(Rr,ma,Zr);CHKERRQ(ierr)
ma = PetscConj(ma);
ierr = VecAXPY(Rl,ma,Zl);CHKERRQ(ierr);
if (ksp->normtype == KSP_NORM_PRECONDITIONED) {
ierr = KSP_PCApply(ksp,Rr,Zr);CHKERRQ(ierr); /* z <- Br */
ierr = VecConjugate(Rl);CHKERRQ(ierr);
ierr = KSP_PCApplyTranspose(ksp,Rl,Zl);CHKERRQ(ierr);
ierr = VecConjugate(Rl);CHKERRQ(ierr);
ierr = VecConjugate(Zl);CHKERRQ(ierr);
ierr = VecNorm(Zr,NORM_2,&dp);CHKERRQ(ierr); /* dp <- z'*z */
} else {
ierr = VecNorm(Rr,NORM_2,&dp);CHKERRQ(ierr); /* dp <- r'*r */
}
ierr = PetscObjectTakeAccess(ksp);CHKERRQ(ierr);
ksp->its = i+1;
ksp->rnorm = dp;
ierr = PetscObjectGrantAccess(ksp);CHKERRQ(ierr);
KSPLogResidualHistory(ksp,dp);
KSPMonitor(ksp,i+1,dp);
ierr = (*ksp->converged)(ksp,i+1,dp,&ksp->reason,ksp->cnvP);CHKERRQ(ierr);
if (ksp->reason) break;
if (ksp->normtype == KSP_NORM_UNPRECONDITIONED) {
ierr = KSP_PCApply(ksp,Rr,Zr);CHKERRQ(ierr); /* z <- Br */
ierr = VecConjugate(Rl);CHKERRQ(ierr);
ierr = KSP_PCApplyTranspose(ksp,Rl,Zl);CHKERRQ(ierr);
ierr = VecConjugate(Rl);CHKERRQ(ierr);
ierr = VecConjugate(Zl);CHKERRQ(ierr);
}
i++;
} while (i<ksp->max_it);
if (i >= ksp->max_it) {
ksp->reason = KSP_DIVERGED_ITS;
}
PetscFunctionReturn(0);
}
