#ifndef _SNESNGMRES_H
#define _SNESNGMRES_H

#include <private/snesimpl.h>

/*  Data structure for the Nonlinear GMRES method.  */
typedef struct {
 
  /* Solver parameters and counters */
  PetscInt     msize;          /* maximum size of krylov space */
  PetscInt     k_rmax;         /* maximum number of iterations before restart */
  PetscBool    debug;          /* debugging output for NGMRES */
  /* History and subspace data */
  Vec          *rdot;          /* residual history -- length msize */ 
  Vec          *xdot;          /* solution history -- length msize */
  PetscReal     *r_norms;      /* the residual norm history  */

  /* General minimization problem context */
  PetscScalar  *h;             /* the constraint matrix */
  PetscScalar  *beta;          /* rhs for the minimization problem */
  PetscScalar    *xi;          /* the dot-product of the current and previous res. */

  /* Selection constants */
  PetscReal gammaA;          /* Criterion A residual tolerance */
  PetscReal epsilonB;        /* Criterion B difference tolerance */
  PetscReal deltaB;          /* Criterion B residual tolerance */
  PetscReal gammaC;          /* Restart residual tolerance */

  /* LS Minimization solve context */
  PetscScalar  *q;    /* the matrix formed as q_ij = (rdot_i, rdot_j) */
  PetscBLASInt m;     /* matrix dimension */
  PetscBLASInt n;     /* matrix dimension */
  PetscBLASInt nrhs;  /* the number of right hand sides */
  PetscBLASInt lda;   /* the padded matrix dimension */
  PetscBLASInt ldb;   /* the padded vector dimension */
  PetscReal * s;      /* the singular values */
  PetscReal rcond;    /* the exit condition */
  PetscBLASInt rank;  /* the effective rank */
  PetscScalar * work; /* the work vector */
  PetscReal  * rwork; /* the real work vector used for complex */
  PetscBLASInt lwork; /* the size of the work vector */
  PetscBLASInt info;  /* the output condition */

} SNES_NGMRES;

#define H(i,j)  ngmres->h[i*ngmres->msize + j]
#define Q(i,j)  ngmres->q[i*ngmres->msize + j]

#endif