2: /*
  3:    Context for a Newton trust region method for solving a system
  4:    of nonlinear equations
  5:  */

  9:  #include <petsc/private/snesimpl.h>

 11: typedef struct {
 12:   /* ---- Parameters used by the trust region method  ---- */
 13:   PetscReal      mu;             /* used to compute trust region parameter */
 14:   PetscReal      eta;            /* used to compute trust region parameter */
 15:   PetscReal      delta;          /* trust region parameter */
 16:   PetscReal      delta0;         /* used to initialize trust region parameter */
 17:   PetscReal      delta1;         /* used to compute trust region parameter */
 18:   PetscReal      delta2;         /* used to compute trust region parameter */
 19:   PetscReal      delta3;         /* used to compute trust region parameter */
 20:   PetscReal      sigma;          /* used to detemine termination */
 21:   PetscBool      itflag;         /* flag for convergence testing */
 22:   PetscReal      rnorm0,ttol;    /* used for KSP convergence test */
 23:   PetscErrorCode (*precheck)(SNES,Vec,Vec,PetscBool*,void*);
 24:   void           *precheckctx;
 25:   PetscErrorCode (*postcheck)(SNES,Vec,Vec,Vec,PetscBool*,PetscBool*,void*);
 26:   void           *postcheckctx;
 27: } SNES_NEWTONTR;

 29: #endif