Dave Lee via petsc-users <petsc-users@mcs.anl.gov> writes: > Hi Petsc, > > I'm attempting to implement a "hookstep" for the SNES trust region solver. > Essentially what I'm trying to do is replace the solution of the least > squares problem at the end of each GMRES solve with a modified solution > with a norm that is constrained to be within the size of the trust region. > > In order to do this I need to perform an SVD on the Hessenberg matrix, > which copying the function KSPComputeExtremeSingularValues(), I'm trying to > do by accessing the LAPACK function dgesvd() via the PetscStackCallBLAS() > machinery. One thing I'm confused about however is the ordering of the 2D > arrays into and out of this function, given that that C and FORTRAN arrays > use reverse indexing, ie: C[j+1][i+1] = F[i,j]. > > Given that the Hessenberg matrix has k+1 rows and k columns, should I be > still be initializing this as H[row][col] and passing this into > PetscStackCallBLAS("LAPACKgesvd",LAPACKgrsvd_(...)) > or should I be transposing this before passing it in?
LAPACK terminology is with respect to Fortran ordering. There is a "leading dimension" parameter so that you can operate on non-contiguous blocks. See KSPComputeExtremeSingularValues_GMRES for an example. > Also for the left and right singular vector matrices that are returned by > this function, should I be transposing these before I interpret them as C > arrays? > > I've attached my modified version of gmres.c in case this is helpful. If > you grep for DRL (my initials) then you'll see my changes to the code. > > Cheers, Dave. > > /* > This file implements GMRES (a Generalized Minimal Residual) method. > Reference: Saad and Schultz, 1986. > > > Some comments on left vs. right preconditioning, and restarts. > Left and right preconditioning. > If right preconditioning is chosen, then the problem being solved > by gmres is actually > My = AB^-1 y = f > so the initial residual is > r = f - Mx > Note that B^-1 y = x or y = B x, and if x is non-zero, the initial > residual is > r = f - A x > The final solution is then > x = B^-1 y > > If left preconditioning is chosen, then the problem being solved is > My = B^-1 A x = B^-1 f, > and the initial residual is > r = B^-1(f - Ax) > > Restarts: Restarts are basically solves with x0 not equal to zero. > Note that we can eliminate an extra application of B^-1 between > restarts as long as we don't require that the solution at the end > of an unsuccessful gmres iteration always be the solution x. > */ > > #include <../src/ksp/ksp/impls/gmres/gmresimpl.h> /*I "petscksp.h" I*/ > #include <petscblaslapack.h> // DRL > #define GMRES_DELTA_DIRECTIONS 10 > #define GMRES_DEFAULT_MAXK 30 > static PetscErrorCode > KSPGMRESUpdateHessenberg(KSP,PetscInt,PetscBool,PetscReal*); > static PetscErrorCode KSPGMRESBuildSoln(PetscScalar*,Vec,Vec,KSP,PetscInt); > > PetscErrorCode KSPSetUp_GMRES(KSP ksp) > { > PetscInt hh,hes,rs,cc; > PetscErrorCode ierr; > PetscInt max_k,k; > KSP_GMRES *gmres = (KSP_GMRES*)ksp->data; > > PetscFunctionBegin; > max_k = gmres->max_k; /* restart size */ > hh = (max_k + 2) * (max_k + 1); > hes = (max_k + 1) * (max_k + 1); > rs = (max_k + 2); > cc = (max_k + 1); > > ierr = > PetscCalloc5(hh,&gmres->hh_origin,hes,&gmres->hes_origin,rs,&gmres->rs_origin,cc,&gmres->cc_origin,cc,&gmres->ss_origin);CHKERRQ(ierr); > ierr = PetscLogObjectMemory((PetscObject)ksp,(hh + hes + rs + > 2*cc)*sizeof(PetscScalar));CHKERRQ(ierr); > > if (ksp->calc_sings) { > /* Allocate workspace to hold Hessenberg matrix needed by lapack */ > ierr = PetscMalloc1((max_k + 3)*(max_k + 9),&gmres->Rsvd);CHKERRQ(ierr); > ierr = PetscLogObjectMemory((PetscObject)ksp,(max_k + 3)*(max_k + > 9)*sizeof(PetscScalar));CHKERRQ(ierr); > ierr = PetscMalloc1(6*(max_k+2),&gmres->Dsvd);CHKERRQ(ierr); > ierr = > PetscLogObjectMemory((PetscObject)ksp,6*(max_k+2)*sizeof(PetscReal));CHKERRQ(ierr); > } > > /* Allocate array to hold pointers to user vectors. Note that we need > 4 + max_k + 1 (since we need it+1 vectors, and it <= max_k) */ > gmres->vecs_allocated = VEC_OFFSET + 2 + max_k + gmres->nextra_vecs; > > ierr = PetscMalloc1(gmres->vecs_allocated,&gmres->vecs);CHKERRQ(ierr); > ierr = PetscMalloc1(VEC_OFFSET+2+max_k,&gmres->user_work);CHKERRQ(ierr); > ierr = PetscMalloc1(VEC_OFFSET+2+max_k,&gmres->mwork_alloc);CHKERRQ(ierr); > ierr = > PetscLogObjectMemory((PetscObject)ksp,(VEC_OFFSET+2+max_k)*(sizeof(Vec*)+sizeof(PetscInt)) > + gmres->vecs_allocated*sizeof(Vec));CHKERRQ(ierr); > > if (gmres->q_preallocate) { > gmres->vv_allocated = VEC_OFFSET + 2 + max_k; > > ierr = > KSPCreateVecs(ksp,gmres->vv_allocated,&gmres->user_work[0],0,NULL);CHKERRQ(ierr); > ierr = > PetscLogObjectParents(ksp,gmres->vv_allocated,gmres->user_work[0]);CHKERRQ(ierr); > > gmres->mwork_alloc[0] = gmres->vv_allocated; > gmres->nwork_alloc = 1; > for (k=0; k<gmres->vv_allocated; k++) { > gmres->vecs[k] = gmres->user_work[0][k]; > } > } else { > gmres->vv_allocated = 5; > > ierr = KSPCreateVecs(ksp,5,&gmres->user_work[0],0,NULL);CHKERRQ(ierr); > ierr = PetscLogObjectParents(ksp,5,gmres->user_work[0]);CHKERRQ(ierr); > > gmres->mwork_alloc[0] = 5; > gmres->nwork_alloc = 1; > for (k=0; k<gmres->vv_allocated; k++) { > gmres->vecs[k] = gmres->user_work[0][k]; > } > } > PetscFunctionReturn(0); > } > > /* > Run gmres, possibly with restart. Return residual history if requested. > input parameters: > > . gmres - structure containing parameters and work areas > > output parameters: > . nres - residuals (from preconditioned system) at each step. > If restarting, consider passing nres+it. If null, > ignored > . itcount - number of iterations used. nres[0] to nres[itcount] > are defined. If null, ignored. > > Notes: > On entry, the value in vector VEC_VV(0) should be the initial residual > (this allows shortcuts where the initial preconditioned residual is 0). > */ > PetscErrorCode KSPGMRESCycle(PetscInt *itcount,KSP ksp) > { > KSP_GMRES *gmres = (KSP_GMRES*)(ksp->data); > PetscReal res_norm,res,hapbnd,tt; > PetscErrorCode ierr; > PetscInt it = 0, max_k = gmres->max_k; > PetscBool hapend = PETSC_FALSE; > > PetscFunctionBegin; > if (itcount) *itcount = 0; > ierr = VecNormalize(VEC_VV(0),&res_norm);CHKERRQ(ierr); > KSPCheckNorm(ksp,res_norm); > res = res_norm; > *GRS(0) = res_norm; > > /* check for the convergence */ > ierr = PetscObjectSAWsTakeAccess((PetscObject)ksp);CHKERRQ(ierr); > ksp->rnorm = res; > ierr = PetscObjectSAWsGrantAccess((PetscObject)ksp);CHKERRQ(ierr); > gmres->it = (it - 1); > ierr = KSPLogResidualHistory(ksp,res);CHKERRQ(ierr); > ierr = KSPMonitor(ksp,ksp->its,res);CHKERRQ(ierr); > if (!res) { > ksp->reason = KSP_CONVERGED_ATOL; > ierr = PetscInfo(ksp,"Converged due to zero residual norm on > entry\n");CHKERRQ(ierr); > PetscFunctionReturn(0); > } > > ierr = > (*ksp->converged)(ksp,ksp->its,res,&ksp->reason,ksp->cnvP);CHKERRQ(ierr); > while (!ksp->reason && it < max_k && ksp->its < ksp->max_it) { > if (it) { > ierr = KSPLogResidualHistory(ksp,res);CHKERRQ(ierr); > ierr = KSPMonitor(ksp,ksp->its,res);CHKERRQ(ierr); > } > gmres->it = (it - 1); > if (gmres->vv_allocated <= it + VEC_OFFSET + 1) { > ierr = KSPGMRESGetNewVectors(ksp,it+1);CHKERRQ(ierr); > } > ierr = > KSP_PCApplyBAorAB(ksp,VEC_VV(it),VEC_VV(1+it),VEC_TEMP_MATOP);CHKERRQ(ierr); > > /* update hessenberg matrix and do Gram-Schmidt */ > ierr = (*gmres->orthog)(ksp,it);CHKERRQ(ierr); > if (ksp->reason) break; > > /* vv(i+1) . vv(i+1) */ > ierr = VecNormalize(VEC_VV(it+1),&tt);CHKERRQ(ierr); > > /* save the magnitude */ > *HH(it+1,it) = tt; > *HES(it+1,it) = tt; > > /* check for the happy breakdown */ > hapbnd = PetscAbsScalar(tt / *GRS(it)); > if (hapbnd > gmres->haptol) hapbnd = gmres->haptol; > if (tt < hapbnd) { > ierr = PetscInfo2(ksp,"Detected happy breakdown, current hapbnd = > %14.12e tt = %14.12e\n",(double)hapbnd,(double)tt);CHKERRQ(ierr); > hapend = PETSC_TRUE; > } > ierr = KSPGMRESUpdateHessenberg(ksp,it,hapend,&res);CHKERRQ(ierr); > > it++; > gmres->it = (it-1); /* For converged */ > ksp->its++; > ksp->rnorm = res; > if (ksp->reason) break; > > ierr = > (*ksp->converged)(ksp,ksp->its,res,&ksp->reason,ksp->cnvP);CHKERRQ(ierr); > > /* Catch error in happy breakdown and signal convergence and break from > loop */ > if (hapend) { > if (!ksp->reason) { > if (ksp->errorifnotconverged) > SETERRQ1(PetscObjectComm((PetscObject)ksp),PETSC_ERR_NOT_CONVERGED,"You > reached the happy break down, but convergence was not indicated. Residual > norm = %g",(double)res); > else { > ksp->reason = KSP_DIVERGED_BREAKDOWN; > break; > } > } > } > } > > /* Monitor if we know that we will not return for a restart */ > if (it && (ksp->reason || ksp->its >= ksp->max_it)) { > ierr = KSPLogResidualHistory(ksp,res);CHKERRQ(ierr); > ierr = KSPMonitor(ksp,ksp->its,res);CHKERRQ(ierr); > } > > if (itcount) *itcount = it; > > > /* > Down here we have to solve for the "best" coefficients of the Krylov > columns, add the solution values together, and possibly unwind the > preconditioning from the solution > */ > /* Form the solution (or the solution so far) */ > ierr = > KSPGMRESBuildSoln(GRS(0),ksp->vec_sol,ksp->vec_sol,ksp,it-1);CHKERRQ(ierr); > PetscFunctionReturn(0); > } > > PetscErrorCode KSPSolve_GMRES(KSP ksp) > { > PetscErrorCode ierr; > PetscInt its,itcount,i; > KSP_GMRES *gmres = (KSP_GMRES*)ksp->data; > PetscBool guess_zero = ksp->guess_zero; > PetscInt N = gmres->max_k + 1; > PetscBLASInt bN; > > PetscFunctionBegin; > if (ksp->calc_sings && !gmres->Rsvd) > SETERRQ(PetscObjectComm((PetscObject)ksp),PETSC_ERR_ORDER,"Must call > KSPSetComputeSingularValues() before KSPSetUp() is called"); > > ierr = PetscObjectSAWsTakeAccess((PetscObject)ksp);CHKERRQ(ierr); > ksp->its = 0; > ierr = PetscObjectSAWsGrantAccess((PetscObject)ksp);CHKERRQ(ierr); > > itcount = 0; > gmres->fullcycle = 0; > ksp->reason = KSP_CONVERGED_ITERATING; > while (!ksp->reason) { > ierr = > KSPInitialResidual(ksp,ksp->vec_sol,VEC_TEMP,VEC_TEMP_MATOP,VEC_VV(0),ksp->vec_rhs);CHKERRQ(ierr); > ierr = KSPGMRESCycle(&its,ksp);CHKERRQ(ierr); > /* Store the Hessenberg matrix and the basis vectors of the Krylov > subspace > if the cycle is complete for the computation of the Ritz pairs */ > if (its == gmres->max_k) { > gmres->fullcycle++; > if (ksp->calc_ritz) { > if (!gmres->hes_ritz) { > ierr = PetscMalloc1(N*N,&gmres->hes_ritz);CHKERRQ(ierr); > ierr = > PetscLogObjectMemory((PetscObject)ksp,N*N*sizeof(PetscScalar));CHKERRQ(ierr); > ierr = VecDuplicateVecs(VEC_VV(0),N,&gmres->vecb);CHKERRQ(ierr); > } > ierr = PetscBLASIntCast(N,&bN);CHKERRQ(ierr); > ierr = > PetscMemcpy(gmres->hes_ritz,gmres->hes_origin,bN*bN*sizeof(PetscReal));CHKERRQ(ierr); > for (i=0; i<gmres->max_k+1; i++) { > ierr = VecCopy(VEC_VV(i),gmres->vecb[i]);CHKERRQ(ierr); > } > } > } > itcount += its; > if (itcount >= ksp->max_it) { > if (!ksp->reason) ksp->reason = KSP_DIVERGED_ITS; > break; > } > ksp->guess_zero = PETSC_FALSE; /* every future call to > KSPInitialResidual() will have nonzero guess */ > } > ksp->guess_zero = guess_zero; /* restore if user provided nonzero initial > guess */ > PetscFunctionReturn(0); > } > > PetscErrorCode KSPReset_GMRES(KSP ksp) > { > KSP_GMRES *gmres = (KSP_GMRES*)ksp->data; > PetscErrorCode ierr; > PetscInt i; > > PetscFunctionBegin; > /* Free the Hessenberg matrices */ > ierr = > PetscFree6(gmres->hh_origin,gmres->hes_origin,gmres->rs_origin,gmres->cc_origin,gmres->ss_origin,gmres->hes_ritz);CHKERRQ(ierr); > > /* free work vectors */ > ierr = PetscFree(gmres->vecs);CHKERRQ(ierr); > for (i=0; i<gmres->nwork_alloc; i++) { > ierr = > VecDestroyVecs(gmres->mwork_alloc[i],&gmres->user_work[i]);CHKERRQ(ierr); > } > gmres->nwork_alloc = 0; > if (gmres->vecb) { > ierr = VecDestroyVecs(gmres->max_k+1,&gmres->vecb);CHKERRQ(ierr); > } > > ierr = PetscFree(gmres->user_work);CHKERRQ(ierr); > ierr = PetscFree(gmres->mwork_alloc);CHKERRQ(ierr); > ierr = PetscFree(gmres->nrs);CHKERRQ(ierr); > ierr = VecDestroy(&gmres->sol_temp);CHKERRQ(ierr); > ierr = PetscFree(gmres->Rsvd);CHKERRQ(ierr); > ierr = PetscFree(gmres->Dsvd);CHKERRQ(ierr); > ierr = PetscFree(gmres->orthogwork);CHKERRQ(ierr); > > gmres->sol_temp = 0; > gmres->vv_allocated = 0; > gmres->vecs_allocated = 0; > gmres->sol_temp = 0; > PetscFunctionReturn(0); > } > > PetscErrorCode KSPDestroy_GMRES(KSP ksp) > { > PetscErrorCode ierr; > > PetscFunctionBegin; > ierr = KSPReset_GMRES(ksp);CHKERRQ(ierr); > ierr = PetscFree(ksp->data);CHKERRQ(ierr); > /* clear composed functions */ > ierr = > PetscObjectComposeFunction((PetscObject)ksp,"KSPGMRESSetPreAllocateVectors_C",NULL);CHKERRQ(ierr); > ierr = > PetscObjectComposeFunction((PetscObject)ksp,"KSPGMRESSetOrthogonalization_C",NULL);CHKERRQ(ierr); > ierr = > PetscObjectComposeFunction((PetscObject)ksp,"KSPGMRESGetOrthogonalization_C",NULL);CHKERRQ(ierr); > ierr = > PetscObjectComposeFunction((PetscObject)ksp,"KSPGMRESSetRestart_C",NULL);CHKERRQ(ierr); > ierr = > PetscObjectComposeFunction((PetscObject)ksp,"KSPGMRESGetRestart_C",NULL);CHKERRQ(ierr); > ierr = > PetscObjectComposeFunction((PetscObject)ksp,"KSPGMRESSetHapTol_C",NULL);CHKERRQ(ierr); > ierr = > PetscObjectComposeFunction((PetscObject)ksp,"KSPGMRESSetCGSRefinementType_C",NULL);CHKERRQ(ierr); > ierr = > PetscObjectComposeFunction((PetscObject)ksp,"KSPGMRESGetCGSRefinementType_C",NULL);CHKERRQ(ierr); > PetscFunctionReturn(0); > } > /* > KSPGMRESBuildSoln - create the solution from the starting vector and the > current iterates. > > Input parameters: > nrs - work area of size it + 1. > vs - index of initial guess > vdest - index of result. Note that vs may == vdest (replace > guess with the solution). > > This is an internal routine that knows about the GMRES internals. > */ > static PetscErrorCode KSPGMRESBuildSoln(PetscScalar *nrs,Vec vs,Vec vdest,KSP > ksp,PetscInt it) > { > PetscScalar tt; > PetscErrorCode ierr; > PetscInt ii,k,j; > KSP_GMRES *gmres = (KSP_GMRES*)(ksp->data); > > PetscFunctionBegin; > /* Solve for solution vector that minimizes the residual */ > > /* If it is < 0, no gmres steps have been performed */ > if (it < 0) { > ierr = VecCopy(vs,vdest);CHKERRQ(ierr); /* VecCopy() is smart, exists > immediately if vguess == vdest */ > PetscFunctionReturn(0); > } > if (*HH(it,it) != 0.0) { > nrs[it] = *GRS(it) / *HH(it,it); > } else { > ksp->reason = KSP_DIVERGED_BREAKDOWN; > > ierr = PetscInfo2(ksp,"Likely your matrix or preconditioner is singular. > HH(it,it) is identically zero; it = %D GRS(it) = > %g\n",it,(double)PetscAbsScalar(*GRS(it)));CHKERRQ(ierr); > PetscFunctionReturn(0); > } > for (ii=1; ii<=it; ii++) { > k = it - ii; > tt = *GRS(k); > for (j=k+1; j<=it; j++) tt = tt - *HH(k,j) * nrs[j]; > if (*HH(k,k) == 0.0) { > ksp->reason = KSP_DIVERGED_BREAKDOWN; > > ierr = PetscInfo1(ksp,"Likely your matrix or preconditioner is > singular. HH(k,k) is identically zero; k = %D\n",k);CHKERRQ(ierr); > PetscFunctionReturn(0); > } > nrs[k] = tt / *HH(k,k); > } > > /* Perform the hookstep correction - DRL */ > if(gmres->delta > 0.0 && gmres->it > 0) { // Apply the hookstep to correct > the GMRES solution (if required) > printf("\t\tapplying hookstep: initial delta: %lf", gmres->delta); > PetscInt N = gmres->max_k+2, ii, jj, j0; > PetscBLASInt nRows, nCols, lwork, lierr; > PetscScalar *R, *work; > PetscReal* S; > PetscScalar *U, *VT, *p, *q, *y; > PetscScalar bnorm, mu, qMag, qMag2, delta2; > > ierr = PetscMalloc1((gmres->max_k + 3)*(gmres->max_k + > 9),&R);CHKERRQ(ierr); > work = R + N*N; > ierr = PetscMalloc1(6*(gmres->max_k+2),&S);CHKERRQ(ierr); > > ierr = PetscBLASIntCast(gmres->it+1,&nRows);CHKERRQ(ierr); > ierr = PetscBLASIntCast(gmres->it+0,&nCols);CHKERRQ(ierr); > ierr = PetscBLASIntCast(5*N,&lwork);CHKERRQ(ierr); > //ierr = > PetscMemcpy(R,gmres->hes_origin,(gmres->max_k+2)*(gmres->max_k+1)*sizeof(PetscScalar));CHKERRQ(ierr); > ierr = PetscMalloc1(nRows*nCols,&R);CHKERRQ(ierr); > for (ii = 0; ii < nRows; ii++) { > for (jj = 0; jj < nCols; jj++) { > R[ii*nCols+jj] = *HH(ii,jj); > // Ensure Hessenberg structure > //if (ii > jj+1) R[ii*nCols+jj] = 0.0; > } > } > > ierr = PetscMalloc1(nRows*nRows,&U);CHKERRQ(ierr); > ierr = PetscMalloc1(nCols*nCols,&VT);CHKERRQ(ierr); > ierr = PetscMalloc1(nRows,&p);CHKERRQ(ierr); > ierr = PetscMalloc1(nCols,&q);CHKERRQ(ierr); > ierr = PetscMalloc1(nRows,&y);CHKERRQ(ierr); > > > printf("\n\n");for(ii=0;ii<nRows;ii++){for(jj=0;jj<nCols;jj++){printf("\t%g",R[ii*nCols+jj]);}printf("\n");}printf("\n"); > > // Perform an SVD on the Hessenberg matrix > ierr = PetscFPTrapPush(PETSC_FP_TRAP_OFF);CHKERRQ(ierr); > > PetscStackCallBLAS("LAPACKgesvd",LAPACKgesvd_("A","A",&nRows,&nCols,R,&nRows,S,U,&nRows,VT,&nCols,work,&lwork,&lierr)); > if (lierr) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_LIB,"Error in SVD Lapack > routine %d",(int)lierr); > ierr = PetscFPTrapPop();CHKERRQ(ierr); > > // Compute p = ||b|| U^T e_1 > ierr = VecNorm(ksp->vec_rhs,NORM_2,&bnorm);CHKERRQ(ierr); > for (ii=0; ii<nRows; ii++) { > p[ii] = bnorm*U[ii*nRows]; > } > > // Solve the root finding problem for \mu such that ||q|| < \delta (where > \delta is the radius of the trust region) > // This step is largely copied from Ashley Willis' openpipeflow: > doi.org/10.1016/j.softx.2017.05.003 > mu = S[nCols-1]*S[nCols-1]*1.0e-6; > if (mu < 1.0e-99) mu = 1.0e-99; > qMag = 1.0e+99; > > while (qMag > gmres->delta) { > mu *= 1.1; > qMag2 = 0.0; > for (ii=0; ii<nCols; ii++) { > q[ii] = p[ii]*S[ii]/(mu + S[ii]*S[ii]); > qMag2 += q[ii]*q[ii]; > } > qMag = PetscSqrtScalar(qMag2); > } > > // Expand y in terms of the right singular vectors as y = V q > for (ii=0; ii<nCols; ii++) { > y[ii] = 0.0; > for (jj=0; jj<nCols; jj++) { > y[ii] += VT[jj*nCols+ii]*q[jj]; // transpose of the transpose > } > } > > // Recompute the size of the trust region, \delta > delta2 = 0.0; > for (ii=0; ii<nRows; ii++) { > j0 = (ii < 2) ? 0 : ii - 1; > p[ii] = 0.0; > for (jj=j0; jj<nCols; jj++) { > p[ii] -= R[ii*nCols+jj]*y[jj]; > } > if (ii == 0) { > p[ii] += bnorm; > } > delta2 += p[ii]*p[ii]; > } > gmres->delta = PetscSqrtScalar(delta2); > printf("\t\t...final delta: %lf.\n", gmres->delta); > > // Pass the orthnomalized Krylov vector weights back out > for (ii=0; ii<nCols; ii++) { > nrs[ii] = y[ii]; > } > > ierr = PetscFree(R);CHKERRQ(ierr); > ierr = PetscFree(S);CHKERRQ(ierr); > ierr = PetscFree(U);CHKERRQ(ierr); > ierr = PetscFree(VT);CHKERRQ(ierr); > ierr = PetscFree(p);CHKERRQ(ierr); > ierr = PetscFree(q);CHKERRQ(ierr); > ierr = PetscFree(y);CHKERRQ(ierr); > } > /*** DRL ***/ > > /* Accumulate the correction to the solution of the preconditioned problem > in TEMP */ > ierr = VecSet(VEC_TEMP,0.0);CHKERRQ(ierr); > if (gmres->delta > 0.0) { > ierr = VecMAXPY(VEC_TEMP,it,nrs,&VEC_VV(0));CHKERRQ(ierr); // DRL > } else { > ierr = VecMAXPY(VEC_TEMP,it+1,nrs,&VEC_VV(0));CHKERRQ(ierr); > } > > ierr = KSPUnwindPreconditioner(ksp,VEC_TEMP,VEC_TEMP_MATOP);CHKERRQ(ierr); > /* add solution to previous solution */ > if (vdest != vs) { > ierr = VecCopy(vs,vdest);CHKERRQ(ierr); > } > ierr = VecAXPY(vdest,1.0,VEC_TEMP);CHKERRQ(ierr); > PetscFunctionReturn(0); > } > /* > Do the scalar work for the orthogonalization. Return new residual norm. > */ > static PetscErrorCode KSPGMRESUpdateHessenberg(KSP ksp,PetscInt it,PetscBool > hapend,PetscReal *res) > { > PetscScalar *hh,*cc,*ss,tt; > PetscInt j; > KSP_GMRES *gmres = (KSP_GMRES*)(ksp->data); > > PetscFunctionBegin; > hh = HH(0,it); > cc = CC(0); > ss = SS(0); > > /* Apply all the previously computed plane rotations to the new column > of the Hessenberg matrix */ > for (j=1; j<=it; j++) { > tt = *hh; > *hh = PetscConj(*cc) * tt + *ss * *(hh+1); > hh++; > *hh = *cc++ * *hh - (*ss++ * tt); > } > > /* > compute the new plane rotation, and apply it to: > 1) the right-hand-side of the Hessenberg system > 2) the new column of the Hessenberg matrix > thus obtaining the updated value of the residual > */ > if (!hapend) { > tt = PetscSqrtScalar(PetscConj(*hh) * *hh + PetscConj(*(hh+1)) * *(hh+1)); > if (tt == 0.0) { > ksp->reason = KSP_DIVERGED_NULL; > PetscFunctionReturn(0); > } > *cc = *hh / tt; > *ss = *(hh+1) / tt; > *GRS(it+1) = -(*ss * *GRS(it)); > *GRS(it) = PetscConj(*cc) * *GRS(it); > *hh = PetscConj(*cc) * *hh + *ss * *(hh+1); > *res = PetscAbsScalar(*GRS(it+1)); > } else { > /* happy breakdown: HH(it+1, it) = 0, therfore we don't need to apply > another rotation matrix (so RH doesn't change). The new residual > is > always the new sine term times the residual from last time > (GRS(it)), > but now the new sine rotation would be zero...so the residual > should > be zero...so we will multiply "zero" by the last residual. This > might > not be exactly what we want to do here -could just return "zero". > */ > > *res = 0.0; > } > PetscFunctionReturn(0); > } > /* > This routine allocates more work vectors, starting from VEC_VV(it). > */ > PetscErrorCode KSPGMRESGetNewVectors(KSP ksp,PetscInt it) > { > KSP_GMRES *gmres = (KSP_GMRES*)ksp->data; > PetscErrorCode ierr; > PetscInt nwork = gmres->nwork_alloc,k,nalloc; > > PetscFunctionBegin; > nalloc = PetscMin(ksp->max_it,gmres->delta_allocate); > /* Adjust the number to allocate to make sure that we don't exceed the > number of available slots */ > if (it + VEC_OFFSET + nalloc >= gmres->vecs_allocated) { > nalloc = gmres->vecs_allocated - it - VEC_OFFSET; > } > if (!nalloc) PetscFunctionReturn(0); > > gmres->vv_allocated += nalloc; > > ierr = > KSPCreateVecs(ksp,nalloc,&gmres->user_work[nwork],0,NULL);CHKERRQ(ierr); > ierr = > PetscLogObjectParents(ksp,nalloc,gmres->user_work[nwork]);CHKERRQ(ierr); > > gmres->mwork_alloc[nwork] = nalloc; > for (k=0; k<nalloc; k++) { > gmres->vecs[it+VEC_OFFSET+k] = gmres->user_work[nwork][k]; > } > gmres->nwork_alloc++; > PetscFunctionReturn(0); > } > > PetscErrorCode KSPBuildSolution_GMRES(KSP ksp,Vec ptr,Vec *result) > { > KSP_GMRES *gmres = (KSP_GMRES*)ksp->data; > PetscErrorCode ierr; > > PetscFunctionBegin; > if (!ptr) { > if (!gmres->sol_temp) { > ierr = VecDuplicate(ksp->vec_sol,&gmres->sol_temp);CHKERRQ(ierr); > ierr = > PetscLogObjectParent((PetscObject)ksp,(PetscObject)gmres->sol_temp);CHKERRQ(ierr); > } > ptr = gmres->sol_temp; > } > if (!gmres->nrs) { > /* allocate the work area */ > ierr = PetscMalloc1(gmres->max_k,&gmres->nrs);CHKERRQ(ierr); > ierr = > PetscLogObjectMemory((PetscObject)ksp,gmres->max_k*sizeof(PetscScalar));CHKERRQ(ierr); > } > > ierr = > KSPGMRESBuildSoln(gmres->nrs,ksp->vec_sol,ptr,ksp,gmres->it);CHKERRQ(ierr); > if (result) *result = ptr; > PetscFunctionReturn(0); > } > > PetscErrorCode KSPView_GMRES(KSP ksp,PetscViewer viewer) > { > KSP_GMRES *gmres = (KSP_GMRES*)ksp->data; > const char *cstr; > PetscErrorCode ierr; > PetscBool iascii,isstring; > > PetscFunctionBegin; > ierr = > PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr); > ierr = > PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSTRING,&isstring);CHKERRQ(ierr); > if (gmres->orthog == KSPGMRESClassicalGramSchmidtOrthogonalization) { > switch (gmres->cgstype) { > case (KSP_GMRES_CGS_REFINE_NEVER): > cstr = "Classical (unmodified) Gram-Schmidt Orthogonalization with no > iterative refinement"; > break; > case (KSP_GMRES_CGS_REFINE_ALWAYS): > cstr = "Classical (unmodified) Gram-Schmidt Orthogonalization with one > step of iterative refinement"; > break; > case (KSP_GMRES_CGS_REFINE_IFNEEDED): > cstr = "Classical (unmodified) Gram-Schmidt Orthogonalization with one > step of iterative refinement when needed"; > break; > default: > > SETERRQ(PetscObjectComm((PetscObject)ksp),PETSC_ERR_ARG_OUTOFRANGE,"Unknown > orthogonalization"); > } > } else if (gmres->orthog == KSPGMRESModifiedGramSchmidtOrthogonalization) { > cstr = "Modified Gram-Schmidt Orthogonalization"; > } else { > cstr = "unknown orthogonalization"; > } > if (iascii) { > ierr = PetscViewerASCIIPrintf(viewer," restart=%D, using > %s\n",gmres->max_k,cstr);CHKERRQ(ierr); > ierr = PetscViewerASCIIPrintf(viewer," happy breakdown tolerance > %g\n",(double)gmres->haptol);CHKERRQ(ierr); > } else if (isstring) { > ierr = PetscViewerStringSPrintf(viewer,"%s restart > %D",cstr,gmres->max_k);CHKERRQ(ierr); > } > PetscFunctionReturn(0); > } > > /*@C > KSPGMRESMonitorKrylov - Calls VecView() for each new direction in the > GMRES accumulated Krylov space. > > Collective on KSP > > Input Parameters: > + ksp - the KSP context > . its - iteration number > . fgnorm - 2-norm of residual (or gradient) > - dummy - an collection of viewers created with KSPViewerCreate() > > Options Database Keys: > . -ksp_gmres_kyrlov_monitor > > Notes: A new PETSCVIEWERDRAW is created for each Krylov vector so they can > all be simultaneously viewed > Level: intermediate > > .keywords: KSP, nonlinear, vector, monitor, view, Krylov space > > .seealso: KSPMonitorSet(), KSPMonitorDefault(), VecView(), > KSPViewersCreate(), KSPViewersDestroy() > @*/ > PetscErrorCode KSPGMRESMonitorKrylov(KSP ksp,PetscInt its,PetscReal > fgnorm,void *dummy) > { > PetscViewers viewers = (PetscViewers)dummy; > KSP_GMRES *gmres = (KSP_GMRES*)ksp->data; > PetscErrorCode ierr; > Vec x; > PetscViewer viewer; > PetscBool flg; > > PetscFunctionBegin; > ierr = PetscViewersGetViewer(viewers,gmres->it+1,&viewer);CHKERRQ(ierr); > ierr = > PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&flg);CHKERRQ(ierr); > if (!flg) { > ierr = PetscViewerSetType(viewer,PETSCVIEWERDRAW);CHKERRQ(ierr); > ierr = PetscViewerDrawSetInfo(viewer,NULL,"Krylov GMRES > Monitor",PETSC_DECIDE,PETSC_DECIDE,300,300);CHKERRQ(ierr); > } > x = VEC_VV(gmres->it+1); > ierr = VecView(x,viewer);CHKERRQ(ierr); > PetscFunctionReturn(0); > } > > PetscErrorCode KSPSetFromOptions_GMRES(PetscOptionItems > *PetscOptionsObject,KSP ksp) > { > PetscErrorCode ierr; > PetscInt restart; > PetscReal haptol; > KSP_GMRES *gmres = (KSP_GMRES*)ksp->data; > PetscBool flg; > > PetscFunctionBegin; > ierr = PetscOptionsHead(PetscOptionsObject,"KSP GMRES > Options");CHKERRQ(ierr); > ierr = PetscOptionsInt("-ksp_gmres_restart","Number of Krylov search > directions","KSPGMRESSetRestart",gmres->max_k,&restart,&flg);CHKERRQ(ierr); > if (flg) { ierr = KSPGMRESSetRestart(ksp,restart);CHKERRQ(ierr); } > ierr = PetscOptionsReal("-ksp_gmres_haptol","Tolerance for exact > convergence (happy > ending)","KSPGMRESSetHapTol",gmres->haptol,&haptol,&flg);CHKERRQ(ierr); > if (flg) { ierr = KSPGMRESSetHapTol(ksp,haptol);CHKERRQ(ierr); } > flg = PETSC_FALSE; > ierr = PetscOptionsBool("-ksp_gmres_preallocate","Preallocate Krylov > vectors","KSPGMRESSetPreAllocateVectors",flg,&flg,NULL);CHKERRQ(ierr); > if (flg) {ierr = KSPGMRESSetPreAllocateVectors(ksp);CHKERRQ(ierr);} > ierr = > PetscOptionsBoolGroupBegin("-ksp_gmres_classicalgramschmidt","Classical > (unmodified) Gram-Schmidt > (fast)","KSPGMRESSetOrthogonalization",&flg);CHKERRQ(ierr); > if (flg) {ierr = > KSPGMRESSetOrthogonalization(ksp,KSPGMRESClassicalGramSchmidtOrthogonalization);CHKERRQ(ierr);} > ierr = PetscOptionsBoolGroupEnd("-ksp_gmres_modifiedgramschmidt","Modified > Gram-Schmidt (slow,more > stable)","KSPGMRESSetOrthogonalization",&flg);CHKERRQ(ierr); > if (flg) {ierr = > KSPGMRESSetOrthogonalization(ksp,KSPGMRESModifiedGramSchmidtOrthogonalization);CHKERRQ(ierr);} > ierr = PetscOptionsEnum("-ksp_gmres_cgs_refinement_type","Type of iterative > refinement for classical (unmodified) > Gram-Schmidt","KSPGMRESSetCGSRefinementType", > > KSPGMRESCGSRefinementTypes,(PetscEnum)gmres->cgstype,(PetscEnum*)&gmres->cgstype,&flg);CHKERRQ(ierr); > flg = PETSC_FALSE; > ierr = PetscOptionsBool("-ksp_gmres_krylov_monitor","Plot the Krylov > directions","KSPMonitorSet",flg,&flg,NULL);CHKERRQ(ierr); > if (flg) { > PetscViewers viewers; > ierr = > PetscViewersCreate(PetscObjectComm((PetscObject)ksp),&viewers);CHKERRQ(ierr); > ierr = KSPMonitorSet(ksp,KSPGMRESMonitorKrylov,viewers,(PetscErrorCode > (*)(void**))PetscViewersDestroy);CHKERRQ(ierr); > } > ierr = PetscOptionsTail();CHKERRQ(ierr); > PetscFunctionReturn(0); > } > > PetscErrorCode KSPGMRESSetHapTol_GMRES(KSP ksp,PetscReal tol) > { > KSP_GMRES *gmres = (KSP_GMRES*)ksp->data; > > PetscFunctionBegin; > if (tol < 0.0) > SETERRQ(PetscObjectComm((PetscObject)ksp),PETSC_ERR_ARG_OUTOFRANGE,"Tolerance > must be non-negative"); > gmres->haptol = tol; > PetscFunctionReturn(0); > } > > PetscErrorCode KSPGMRESGetRestart_GMRES(KSP ksp,PetscInt *max_k) > { > KSP_GMRES *gmres = (KSP_GMRES*)ksp->data; > > PetscFunctionBegin; > *max_k = gmres->max_k; > PetscFunctionReturn(0); > } > > PetscErrorCode KSPGMRESSetRestart_GMRES(KSP ksp,PetscInt max_k) > { > KSP_GMRES *gmres = (KSP_GMRES*)ksp->data; > PetscErrorCode ierr; > > PetscFunctionBegin; > if (max_k < 1) > SETERRQ(PetscObjectComm((PetscObject)ksp),PETSC_ERR_ARG_OUTOFRANGE,"Restart > must be positive"); > if (!ksp->setupstage) { > gmres->max_k = max_k; > } else if (gmres->max_k != max_k) { > gmres->max_k = max_k; > ksp->setupstage = KSP_SETUP_NEW; > /* free the data structures, then create them again */ > ierr = KSPReset_GMRES(ksp);CHKERRQ(ierr); > } > PetscFunctionReturn(0); > } > > PetscErrorCode KSPGMRESSetOrthogonalization_GMRES(KSP ksp,FCN fcn) > { > PetscFunctionBegin; > ((KSP_GMRES*)ksp->data)->orthog = fcn; > PetscFunctionReturn(0); > } > > PetscErrorCode KSPGMRESGetOrthogonalization_GMRES(KSP ksp,FCN *fcn) > { > PetscFunctionBegin; > *fcn = ((KSP_GMRES*)ksp->data)->orthog; > PetscFunctionReturn(0); > } > > PetscErrorCode KSPGMRESSetPreAllocateVectors_GMRES(KSP ksp) > { > KSP_GMRES *gmres; > > PetscFunctionBegin; > gmres = (KSP_GMRES*)ksp->data; > gmres->q_preallocate = 1; > PetscFunctionReturn(0); > } > > PetscErrorCode KSPGMRESSetCGSRefinementType_GMRES(KSP > ksp,KSPGMRESCGSRefinementType type) > { > KSP_GMRES *gmres = (KSP_GMRES*)ksp->data; > > PetscFunctionBegin; > gmres->cgstype = type; > PetscFunctionReturn(0); > } > > PetscErrorCode KSPGMRESGetCGSRefinementType_GMRES(KSP > ksp,KSPGMRESCGSRefinementType *type) > { > KSP_GMRES *gmres = (KSP_GMRES*)ksp->data; > > PetscFunctionBegin; > *type = gmres->cgstype; > PetscFunctionReturn(0); > } > > /*@ > KSPGMRESSetCGSRefinementType - Sets the type of iterative refinement to use > in the classical Gram Schmidt orthogonalization. > > Logically Collective on KSP > > Input Parameters: > + ksp - the Krylov space context > - type - the type of refinement > > Options Database: > . -ksp_gmres_cgs_refinement_type <refine_never,refine_ifneeded,refine_always> > > Level: intermediate > > .keywords: KSP, GMRES, iterative refinement > > .seealso: KSPGMRESSetOrthogonalization(), KSPGMRESCGSRefinementType, > KSPGMRESClassicalGramSchmidtOrthogonalization(), > KSPGMRESGetCGSRefinementType(), > KSPGMRESGetOrthogonalization() > @*/ > PetscErrorCode KSPGMRESSetCGSRefinementType(KSP > ksp,KSPGMRESCGSRefinementType type) > { > PetscErrorCode ierr; > > PetscFunctionBegin; > PetscValidHeaderSpecific(ksp,KSP_CLASSID,1); > PetscValidLogicalCollectiveEnum(ksp,type,2); > ierr = > PetscTryMethod(ksp,"KSPGMRESSetCGSRefinementType_C",(KSP,KSPGMRESCGSRefinementType),(ksp,type));CHKERRQ(ierr); > PetscFunctionReturn(0); > } > > /*@ > KSPGMRESGetCGSRefinementType - Gets the type of iterative refinement to use > in the classical Gram Schmidt orthogonalization. > > Not Collective > > Input Parameter: > . ksp - the Krylov space context > > Output Parameter: > . type - the type of refinement > > Options Database: > . -ksp_gmres_cgs_refinement_type <never,ifneeded,always> > > Level: intermediate > > .keywords: KSP, GMRES, iterative refinement > > .seealso: KSPGMRESSetOrthogonalization(), KSPGMRESCGSRefinementType, > KSPGMRESClassicalGramSchmidtOrthogonalization(), > KSPGMRESSetCGSRefinementType(), > KSPGMRESGetOrthogonalization() > @*/ > PetscErrorCode KSPGMRESGetCGSRefinementType(KSP > ksp,KSPGMRESCGSRefinementType *type) > { > PetscErrorCode ierr; > > PetscFunctionBegin; > PetscValidHeaderSpecific(ksp,KSP_CLASSID,1); > ierr = > PetscUseMethod(ksp,"KSPGMRESGetCGSRefinementType_C",(KSP,KSPGMRESCGSRefinementType*),(ksp,type));CHKERRQ(ierr); > PetscFunctionReturn(0); > } > > > /*@ > KSPGMRESSetRestart - Sets number of iterations at which GMRES, FGMRES and > LGMRES restarts. > > Logically Collective on KSP > > Input Parameters: > + ksp - the Krylov space context > - restart - integer restart value > > Options Database: > . -ksp_gmres_restart <positive integer> > > Note: The default value is 30. > > Level: intermediate > > .keywords: KSP, GMRES, restart, iterations > > .seealso: KSPSetTolerances(), KSPGMRESSetOrthogonalization(), > KSPGMRESSetPreAllocateVectors(), KSPGMRESGetRestart() > @*/ > PetscErrorCode KSPGMRESSetRestart(KSP ksp, PetscInt restart) > { > PetscErrorCode ierr; > > PetscFunctionBegin; > PetscValidLogicalCollectiveInt(ksp,restart,2); > > ierr = > PetscTryMethod(ksp,"KSPGMRESSetRestart_C",(KSP,PetscInt),(ksp,restart));CHKERRQ(ierr); > PetscFunctionReturn(0); > } > > /*@ > KSPGMRESGetRestart - Gets number of iterations at which GMRES, FGMRES and > LGMRES restarts. > > Not Collective > > Input Parameter: > . ksp - the Krylov space context > > Output Parameter: > . restart - integer restart value > > Note: The default value is 30. > > Level: intermediate > > .keywords: KSP, GMRES, restart, iterations > > .seealso: KSPSetTolerances(), KSPGMRESSetOrthogonalization(), > KSPGMRESSetPreAllocateVectors(), KSPGMRESSetRestart() > @*/ > PetscErrorCode KSPGMRESGetRestart(KSP ksp, PetscInt *restart) > { > PetscErrorCode ierr; > > PetscFunctionBegin; > ierr = > PetscUseMethod(ksp,"KSPGMRESGetRestart_C",(KSP,PetscInt*),(ksp,restart));CHKERRQ(ierr); > PetscFunctionReturn(0); > } > > /*@ > KSPGMRESSetHapTol - Sets tolerance for determining happy breakdown in > GMRES, FGMRES and LGMRES. > > Logically Collective on KSP > > Input Parameters: > + ksp - the Krylov space context > - tol - the tolerance > > Options Database: > . -ksp_gmres_haptol <positive real value> > > Note: Happy breakdown is the rare case in GMRES where an 'exact' solution > is obtained after > a certain number of iterations. If you attempt more iterations after > this point unstable > things can happen hence very occasionally you may need to set this > value to detect this condition > > Level: intermediate > > .keywords: KSP, GMRES, tolerance > > .seealso: KSPSetTolerances() > @*/ > PetscErrorCode KSPGMRESSetHapTol(KSP ksp,PetscReal tol) > { > PetscErrorCode ierr; > > PetscFunctionBegin; > PetscValidLogicalCollectiveReal(ksp,tol,2); > ierr = > PetscTryMethod((ksp),"KSPGMRESSetHapTol_C",(KSP,PetscReal),((ksp),(tol)));CHKERRQ(ierr); > PetscFunctionReturn(0); > } > > /*MC > KSPGMRES - Implements the Generalized Minimal Residual method. > (Saad and Schultz, 1986) with restart > > > Options Database Keys: > + -ksp_gmres_restart <restart> - the number of Krylov directions to > orthogonalize against > . -ksp_gmres_haptol <tol> - sets the tolerance for "happy ending" (exact > convergence) > . -ksp_gmres_preallocate - preallocate all the Krylov search directions > initially (otherwise groups of > vectors are allocated as needed) > . -ksp_gmres_classicalgramschmidt - use classical (unmodified) Gram-Schmidt > to orthogonalize against the Krylov space (fast) (the default) > . -ksp_gmres_modifiedgramschmidt - use modified Gram-Schmidt in the > orthogonalization (more stable, but slower) > . -ksp_gmres_cgs_refinement_type <never,ifneeded,always> - determine if > iterative refinement is used to increase the > stability of the classical Gram-Schmidt > orthogonalization. > - -ksp_gmres_krylov_monitor - plot the Krylov space generated > > Level: beginner > > Notes: Left and right preconditioning are supported, but not symmetric > preconditioning. > > References: > . 1. - YOUCEF SAAD AND MARTIN H. SCHULTZ, GMRES: A GENERALIZED MINIMAL > RESIDUAL ALGORITHM FOR SOLVING NONSYMMETRIC LINEAR SYSTEMS. > SIAM J. ScI. STAT. COMPUT. Vo|. 7, No. 3, July 1986. > > .seealso: KSPCreate(), KSPSetType(), KSPType (for list of available types), > KSP, KSPFGMRES, KSPLGMRES, > KSPGMRESSetRestart(), KSPGMRESSetHapTol(), > KSPGMRESSetPreAllocateVectors(), KSPGMRESSetOrthogonalization(), > KSPGMRESGetOrthogonalization(), > KSPGMRESClassicalGramSchmidtOrthogonalization(), > KSPGMRESModifiedGramSchmidtOrthogonalization(), > KSPGMRESCGSRefinementType, KSPGMRESSetCGSRefinementType(), > KSPGMRESGetCGSRefinementType(), KSPGMRESMonitorKrylov(), KSPSetPCSide() > > M*/ > > PETSC_EXTERN PetscErrorCode KSPCreate_GMRES(KSP ksp) > { > KSP_GMRES *gmres; > PetscErrorCode ierr; > > PetscFunctionBegin; > ierr = PetscNewLog(ksp,&gmres);CHKERRQ(ierr); > ksp->data = (void*)gmres; > > ierr = > KSPSetSupportedNorm(ksp,KSP_NORM_PRECONDITIONED,PC_LEFT,4);CHKERRQ(ierr); > ierr = > KSPSetSupportedNorm(ksp,KSP_NORM_UNPRECONDITIONED,PC_RIGHT,3);CHKERRQ(ierr); > ierr = > KSPSetSupportedNorm(ksp,KSP_NORM_PRECONDITIONED,PC_SYMMETRIC,2);CHKERRQ(ierr); > ierr = KSPSetSupportedNorm(ksp,KSP_NORM_NONE,PC_RIGHT,1);CHKERRQ(ierr); > ierr = KSPSetSupportedNorm(ksp,KSP_NORM_NONE,PC_LEFT,1);CHKERRQ(ierr); > > ksp->ops->buildsolution = KSPBuildSolution_GMRES; > ksp->ops->setup = KSPSetUp_GMRES; > ksp->ops->solve = KSPSolve_GMRES; > ksp->ops->reset = KSPReset_GMRES; > ksp->ops->destroy = KSPDestroy_GMRES; > ksp->ops->view = KSPView_GMRES; > ksp->ops->setfromoptions = KSPSetFromOptions_GMRES; > ksp->ops->computeextremesingularvalues = > KSPComputeExtremeSingularValues_GMRES; > ksp->ops->computeeigenvalues = KSPComputeEigenvalues_GMRES; > #if !defined(PETSC_USE_COMPLEX) && !defined(PETSC_HAVE_ESSL) > ksp->ops->computeritz = KSPComputeRitz_GMRES; > #endif > ierr = > PetscObjectComposeFunction((PetscObject)ksp,"KSPGMRESSetPreAllocateVectors_C",KSPGMRESSetPreAllocateVectors_GMRES);CHKERRQ(ierr); > ierr = > PetscObjectComposeFunction((PetscObject)ksp,"KSPGMRESSetOrthogonalization_C",KSPGMRESSetOrthogonalization_GMRES);CHKERRQ(ierr); > ierr = > PetscObjectComposeFunction((PetscObject)ksp,"KSPGMRESGetOrthogonalization_C",KSPGMRESGetOrthogonalization_GMRES);CHKERRQ(ierr); > ierr = > PetscObjectComposeFunction((PetscObject)ksp,"KSPGMRESSetRestart_C",KSPGMRESSetRestart_GMRES);CHKERRQ(ierr); > ierr = > PetscObjectComposeFunction((PetscObject)ksp,"KSPGMRESGetRestart_C",KSPGMRESGetRestart_GMRES);CHKERRQ(ierr); > ierr = > PetscObjectComposeFunction((PetscObject)ksp,"KSPGMRESSetHapTol_C",KSPGMRESSetHapTol_GMRES);CHKERRQ(ierr); > ierr = > PetscObjectComposeFunction((PetscObject)ksp,"KSPGMRESSetCGSRefinementType_C",KSPGMRESSetCGSRefinementType_GMRES);CHKERRQ(ierr); > ierr = > PetscObjectComposeFunction((PetscObject)ksp,"KSPGMRESGetCGSRefinementType_C",KSPGMRESGetCGSRefinementType_GMRES);CHKERRQ(ierr); > > gmres->haptol = 1.0e-30; > gmres->q_preallocate = 0; > gmres->delta_allocate = GMRES_DELTA_DIRECTIONS; > gmres->orthog = KSPGMRESClassicalGramSchmidtOrthogonalization; > gmres->nrs = 0; > gmres->sol_temp = 0; > gmres->max_k = GMRES_DEFAULT_MAXK; > gmres->Rsvd = 0; > gmres->cgstype = KSP_GMRES_CGS_REFINE_NEVER; > gmres->orthogwork = 0; > gmres->delta = -1.0; // DRL > PetscFunctionReturn(0); > }