1: /*
  2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
  4:    Copyright (c) 2002-, Universitat Politecnica de Valencia, Spain

  6:    This file is part of SLEPc.
  7:    SLEPc is distributed under a 2-clause BSD license (see LICENSE).
  8:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  9: */
 10: /*
 11:    Private header for NLEIGS
 12: */

 14: #pragma once

 16: #define  LBPOINTS  100   /* default value of the maximum number of Leja-Bagby points */
 17: #define  NDPOINTS  1e4   /* number of discretization points */

 19: typedef struct {
 20:   BV             V;         /* tensor vector basis for the linearization */
 21:   BV             W;         /* tensor vector basis for the linearization */
 22:   PetscInt       nmat;      /* number of interpolation points */
 23:   PetscScalar    *s,*xi;    /* Leja-Bagby points */
 24:   PetscScalar    *beta;     /* scaling factors */
 25:   Mat            *D;        /* divided difference matrices */
 26:   PetscScalar    *coeffD;   /* coefficients for divided differences in split form */
 27:   PetscInt       nshifts;   /* provided number of shifts */
 28:   PetscScalar    *shifts;   /* user-provided shifts for the Rational Krylov variant */
 29:   PetscInt       nshiftsw;  /* actual number of shifts (1 if Krylov-Schur) */
 30:   PetscReal      ddtol;     /* tolerance for divided difference convergence */
 31:   PetscInt       ddmaxit;   /* maximum number of divided difference terms */
 32:   PetscReal      keep;      /* restart parameter */
 33:   PetscBool      lock;      /* locking/non-locking variant */
 34:   PetscInt       idxrk;     /* index of next shift to use */
 35:   KSP            *ksp;      /* ksp array for storing shift factorizations */
 36:   Vec            vrn;       /* random vector with normally distributed value */
 37:   PetscBool      fullbasis; /* use full Krylov basis instead of TOAR basis */
 38:   EPS            eps;       /* eigensolver used in the full basis variant */
 39:   Mat            A;         /* shell matrix used for the eps in full basis */
 40:   Vec            w[6];      /* work vectors */
 41:   void           *singularitiesctx;
 42:   PetscErrorCode (*computesingularities)(NEP,PetscInt*,PetscScalar*,void*);
 43: } NEP_NLEIGS;

 45: typedef struct {
 46:   PetscInt    nmat,maxnmat;
 47:   PetscScalar *coeff;
 48:   Mat         *A;
 49:   Vec         t;
 50: } NEP_NLEIGS_MATSHELL;

 52: static inline PetscErrorCode NEPNLEIGSSetShifts(NEP nep,PetscInt *nshiftsw)
 53: {
 54:   NEP_NLEIGS *ctx = (NEP_NLEIGS*)nep->data;

 56:   PetscFunctionBegin;
 57:   if (!ctx->nshifts) {
 58:     ctx->shifts = &nep->target;
 59:     *nshiftsw = 1;
 60:   } else *nshiftsw = ctx->nshifts;
 61:   PetscFunctionReturn(PETSC_SUCCESS);
 62: }

 64: SLEPC_INTERN PetscErrorCode NEPSetUp_NLEIGS_FullBasis(NEP);
 65: SLEPC_INTERN PetscErrorCode NEPNLEIGSSetEPS_NLEIGS(NEP,EPS);
 66: SLEPC_INTERN PetscErrorCode NEPNLEIGSGetEPS_NLEIGS(NEP,EPS*);
 67: SLEPC_INTERN PetscErrorCode NEPNLEIGSBackTransform(PetscObject,PetscInt,PetscScalar*,PetscScalar *vali);
 68: SLEPC_INTERN PetscErrorCode NEPNLEIGSEvalNRTFunct(NEP,PetscInt,PetscScalar,PetscScalar*);
 69: SLEPC_INTERN PetscErrorCode NEPSolve_NLEIGS_FullBasis(NEP);
 70: SLEPC_INTERN PetscErrorCode NEPSolve_NLEIGS(NEP);