PetscErrorCode EPSSetUp_Lanczos(EPS eps) { EPS_LANCZOS *lanczos = (EPS_LANCZOS*)eps->data; BVOrthogRefineType refine; PetscReal eta; PetscErrorCode ierr; PetscFunctionBegin; ierr = EPSSetDimensions_Default(eps,eps->nev,&eps->ncv,&eps->mpd);CHKERRQ(ierr); if (eps->ncv>eps->nev+eps->mpd) SETERRQ(PetscObjectComm((PetscObject)eps),1,"The value of ncv must not be larger than nev+mpd"); if (!eps->max_it) eps->max_it = PetscMax(100,2*eps->n/eps->ncv); if (!eps->which) { ierr = EPSSetWhichEigenpairs_Default(eps);CHKERRQ(ierr); } switch (eps->which) { case EPS_LARGEST_IMAGINARY: case EPS_SMALLEST_IMAGINARY: case EPS_TARGET_IMAGINARY: SETERRQ(PetscObjectComm((PetscObject)eps),1,"Wrong value of eps->which"); default: ; /* default case to remove warning */ } if (!eps->extraction) { ierr = EPSSetExtraction(eps,EPS_RITZ);CHKERRQ(ierr); } else if (eps->extraction!=EPS_RITZ) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Unsupported extraction type"); if (eps->arbitrary) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Arbitrary selection of eigenpairs not supported in this solver"); ierr = EPSAllocateSolution(eps,1);CHKERRQ(ierr); ierr = EPS_SetInnerProduct(eps);CHKERRQ(ierr); if (lanczos->reorthog != EPS_LANCZOS_REORTHOG_FULL) { ierr = BVGetOrthogonalization(eps->V,NULL,&refine,&eta);CHKERRQ(ierr); ierr = BVSetOrthogonalization(eps->V,BV_ORTHOG_MGS,refine,eta);CHKERRQ(ierr); ierr = PetscInfo(eps,"Switching to MGS orthogonalization\n");CHKERRQ(ierr); } if (lanczos->reorthog == EPS_LANCZOS_REORTHOG_SELECTIVE) { ierr = BVDuplicate(eps->V,&lanczos->AV);CHKERRQ(ierr); } ierr = DSSetType(eps->ds,DSHEP);CHKERRQ(ierr); ierr = DSSetCompact(eps->ds,PETSC_TRUE);CHKERRQ(ierr); ierr = DSAllocate(eps->ds,eps->ncv+1);CHKERRQ(ierr); if (lanczos->reorthog == EPS_LANCZOS_REORTHOG_LOCAL) { ierr = EPSSetWorkVecs(eps,1);CHKERRQ(ierr); } /* dispatch solve method */ if (!eps->ishermitian) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Requested method is only available for Hermitian problems"); if (eps->isgeneralized && eps->ishermitian && !eps->ispositive) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Requested method does not work for indefinite problems"); eps->ops->solve = EPSSolve_Lanczos; PetscFunctionReturn(0); }
PetscErrorCode SVDSetUp_TRLanczos(SVD svd) { PetscErrorCode ierr; PetscInt N; PetscFunctionBegin; ierr = SVDMatGetSize(svd,NULL,&N);CHKERRQ(ierr); ierr = SVDSetDimensions_Default(svd);CHKERRQ(ierr); if (svd->ncv>svd->nsv+svd->mpd) SETERRQ(PetscObjectComm((PetscObject)svd),1,"The value of ncv must not be larger than nev+mpd"); if (!svd->max_it) svd->max_it = PetscMax(N/svd->ncv,100); svd->leftbasis = PETSC_TRUE; ierr = SVDAllocateSolution(svd,1);CHKERRQ(ierr); ierr = DSSetType(svd->ds,DSSVD);CHKERRQ(ierr); ierr = DSSetCompact(svd->ds,PETSC_TRUE);CHKERRQ(ierr); ierr = DSAllocate(svd->ds,svd->ncv);CHKERRQ(ierr); PetscFunctionReturn(0); }
int main(int argc,char **argv) { PetscErrorCode ierr; DS ds; SlepcSC sc; PetscReal *T,*s,re,im; PetscScalar *eigr,*eigi; PetscInt i,n=10,l=2,k=5,ld; PetscViewer viewer; PetscBool verbose; SlepcInitialize(&argc,&argv,(char*)0,help); ierr = PetscOptionsGetInt(NULL,"-n",&n,NULL);CHKERRQ(ierr); ierr = PetscPrintf(PETSC_COMM_WORLD,"Solve a Dense System of type GHIEP with compact storage - dimension %D.\n",n);CHKERRQ(ierr); ierr = PetscOptionsGetInt(NULL,"-l",&l,NULL);CHKERRQ(ierr); ierr = PetscOptionsGetInt(NULL,"-k",&k,NULL);CHKERRQ(ierr); if (l>n || k>n || l>k) SETERRQ(PETSC_COMM_WORLD,1,"Wrong value of dimensions"); ierr = PetscOptionsHasName(NULL,"-verbose",&verbose);CHKERRQ(ierr); /* Create DS object */ ierr = DSCreate(PETSC_COMM_WORLD,&ds);CHKERRQ(ierr); ierr = DSSetType(ds,DSGHIEP);CHKERRQ(ierr); ierr = DSSetFromOptions(ds);CHKERRQ(ierr); ld = n+2; /* test leading dimension larger than n */ ierr = DSAllocate(ds,ld);CHKERRQ(ierr); ierr = DSSetDimensions(ds,n,0,l,k);CHKERRQ(ierr); ierr = DSSetCompact(ds,PETSC_TRUE);CHKERRQ(ierr); /* Set up viewer */ ierr = PetscViewerASCIIGetStdout(PETSC_COMM_WORLD,&viewer);CHKERRQ(ierr); ierr = PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_INFO_DETAIL);CHKERRQ(ierr); ierr = DSView(ds,viewer);CHKERRQ(ierr); ierr = PetscViewerPopFormat(viewer);CHKERRQ(ierr); if (verbose) { ierr = PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_MATLAB);CHKERRQ(ierr); } /* Fill arrow-tridiagonal matrix */ ierr = DSGetArrayReal(ds,DS_MAT_T,&T);CHKERRQ(ierr); ierr = DSGetArrayReal(ds,DS_MAT_D,&s);CHKERRQ(ierr); for (i=0;i<n;i++) T[i] = (PetscReal)(i+1); for (i=k;i<n-1;i++) T[i+ld] = 1.0; for (i=l;i<k;i++) T[i+2*ld] = 1.0; T[2*ld+l+1] = -7; T[ld+k+1] = -7; /* Signature matrix */ for (i=0;i<n;i++) s[i] = 1.0; s[l+1] = -1.0; s[k+1] = -1.0; ierr = DSRestoreArrayReal(ds,DS_MAT_T,&T);CHKERRQ(ierr); ierr = DSRestoreArrayReal(ds,DS_MAT_D,&s);CHKERRQ(ierr); if (l==0 && k==0) { ierr = DSSetState(ds,DS_STATE_INTERMEDIATE);CHKERRQ(ierr); } else { ierr = DSSetState(ds,DS_STATE_RAW);CHKERRQ(ierr); } if (verbose) { ierr = PetscPrintf(PETSC_COMM_WORLD,"Initial - - - - - - - - -\n");CHKERRQ(ierr); ierr = DSView(ds,viewer);CHKERRQ(ierr); } /* Solve */ ierr = PetscCalloc2(n,&eigr,n,&eigi);CHKERRQ(ierr); ierr = DSGetSlepcSC(ds,&sc);CHKERRQ(ierr); sc->comparison = SlepcCompareLargestMagnitude; sc->comparisonctx = NULL; sc->map = NULL; sc->mapobj = NULL; ierr = DSSolve(ds,eigr,eigi);CHKERRQ(ierr); ierr = DSSort(ds,eigr,eigi,NULL,NULL,NULL);CHKERRQ(ierr); if (verbose) { ierr = PetscPrintf(PETSC_COMM_WORLD,"After solve - - - - - - - - -\n");CHKERRQ(ierr); ierr = DSView(ds,viewer);CHKERRQ(ierr); } /* Print eigenvalues */ ierr = PetscPrintf(PETSC_COMM_WORLD,"Computed eigenvalues =\n",n);CHKERRQ(ierr); for (i=0;i<n;i++) { #if defined(PETSC_USE_COMPLEX) re = PetscRealPart(eigr[i]); im = PetscImaginaryPart(eigr[i]); #else re = eigr[i]; im = eigi[i]; #endif if (PetscAbs(im)<1e-10) { ierr = PetscViewerASCIIPrintf(viewer," %.5f\n",(double)re);CHKERRQ(ierr); } else { ierr = PetscViewerASCIIPrintf(viewer," %.5f%+.5fi\n",(double)re,(double)im);CHKERRQ(ierr); } } ierr = PetscFree2(eigr,eigi);CHKERRQ(ierr); ierr = DSDestroy(&ds);CHKERRQ(ierr); ierr = SlepcFinalize(); return 0; }
PetscErrorCode EPSSetUp_KrylovSchur(EPS eps) { PetscErrorCode ierr; EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data; enum { EPS_KS_DEFAULT,EPS_KS_SYMM,EPS_KS_SLICE,EPS_KS_INDEF } variant; PetscFunctionBegin; /* spectrum slicing requires special treatment of default values */ if (eps->which==EPS_ALL) { ierr = EPSSetUp_KrylovSchur_Slice(eps);CHKERRQ(ierr); } else { ierr = EPSSetDimensions_Default(eps,eps->nev,&eps->ncv,&eps->mpd);CHKERRQ(ierr); if (eps->ncv>eps->nev+eps->mpd) SETERRQ(PetscObjectComm((PetscObject)eps),1,"The value of ncv must not be larger than nev+mpd"); if (!eps->max_it) eps->max_it = PetscMax(100,2*eps->n/eps->ncv); if (!eps->which) { ierr = EPSSetWhichEigenpairs_Default(eps);CHKERRQ(ierr); } } if (eps->isgeneralized && eps->ishermitian && !eps->ispositive && eps->arbitrary) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Arbitrary selection of eigenpairs not implemented for indefinite problems"); if (eps->ishermitian && eps->ispositive && (eps->which==EPS_LARGEST_IMAGINARY || eps->which==EPS_SMALLEST_IMAGINARY)) SETERRQ(PetscObjectComm((PetscObject)eps),1,"Wrong value of eps->which"); if (!eps->extraction) { ierr = EPSSetExtraction(eps,EPS_RITZ);CHKERRQ(ierr); } else if (eps->extraction!=EPS_RITZ && eps->extraction!=EPS_HARMONIC) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Unsupported extraction type"); if (!ctx->keep) ctx->keep = 0.5; ierr = EPSAllocateSolution(eps,1);CHKERRQ(ierr); ierr = EPS_SetInnerProduct(eps);CHKERRQ(ierr); if (eps->arbitrary) { ierr = EPSSetWorkVecs(eps,2);CHKERRQ(ierr); } else if (eps->ishermitian && !eps->ispositive){ ierr = EPSSetWorkVecs(eps,1);CHKERRQ(ierr); } /* dispatch solve method */ if (eps->ishermitian) { if (eps->which==EPS_ALL) { if (eps->isgeneralized && !eps->ispositive) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Spectrum slicing not implemented for indefinite problems"); else variant = EPS_KS_SLICE; } else if (eps->isgeneralized && !eps->ispositive) { variant = EPS_KS_INDEF; } else { switch (eps->extraction) { case EPS_RITZ: variant = EPS_KS_SYMM; break; case EPS_HARMONIC: variant = EPS_KS_DEFAULT; break; default: SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Unsupported extraction type"); } } } else { switch (eps->extraction) { case EPS_RITZ: variant = EPS_KS_DEFAULT; break; case EPS_HARMONIC: variant = EPS_KS_DEFAULT; break; default: SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Unsupported extraction type"); } } switch (variant) { case EPS_KS_DEFAULT: eps->ops->solve = EPSSolve_KrylovSchur_Default; eps->ops->computevectors = EPSComputeVectors_Schur; ierr = DSSetType(eps->ds,DSNHEP);CHKERRQ(ierr); ierr = DSAllocate(eps->ds,eps->ncv+1);CHKERRQ(ierr); break; case EPS_KS_SYMM: eps->ops->solve = EPSSolve_KrylovSchur_Symm; eps->ops->computevectors = EPSComputeVectors_Hermitian; ierr = DSSetType(eps->ds,DSHEP);CHKERRQ(ierr); ierr = DSSetCompact(eps->ds,PETSC_TRUE);CHKERRQ(ierr); ierr = DSSetExtraRow(eps->ds,PETSC_TRUE);CHKERRQ(ierr); ierr = DSAllocate(eps->ds,eps->ncv+1);CHKERRQ(ierr); break; case EPS_KS_SLICE: eps->ops->solve = EPSSolve_KrylovSchur_Slice; eps->ops->computevectors = NULL; ierr = DSSetType(eps->ds,DSHEP);CHKERRQ(ierr); ierr = DSSetCompact(eps->ds,PETSC_TRUE);CHKERRQ(ierr); ierr = DSAllocate(eps->ds,ctx->ncv+1);CHKERRQ(ierr); break; case EPS_KS_INDEF: eps->ops->solve = EPSSolve_KrylovSchur_Indefinite; eps->ops->computevectors = EPSComputeVectors_Indefinite; ierr = DSSetType(eps->ds,DSGHIEP);CHKERRQ(ierr); ierr = DSSetCompact(eps->ds,PETSC_TRUE);CHKERRQ(ierr); ierr = DSAllocate(eps->ds,eps->ncv+1);CHKERRQ(ierr); break; default: SETERRQ(PetscObjectComm((PetscObject)eps),1,"Unexpected error"); } PetscFunctionReturn(0); }