Tao_Minimizer.h

#ifndef QNANO_NEW_TAO_MINIMIZER_DEFINED_H
#define QNANO_NEW_TAO_MINIMIZER_DEFINED_H


#include "tools/Parameter_Pointer_Function.h"
#include "slepc/SLEPc_Register_Parameter_Map.h"

class Tao_Minimizer{
public:
  Tao tao;
  Parameter_Map *param_map;

static PetscErrorCode Objective_Function(Tao tao,Vec v,PetscReal* result,void* param){
  PetscErrorCode ierr;
  Parameter_Pointer_Function *fct=(Parameter_Pointer_Function *)param;

  const double *cptr;
  ierr=VecGetArrayRead(v,(const PetscScalar **)&cptr); CHKERRQ(ierr);
  *result=(PetscReal) fct->f(cptr);
  ierr=VecRestoreArrayRead(v,(const PetscScalar **) &cptr); CHKERRQ(ierr);
  return ierr;
}

  PetscErrorCode Set_Initial_Vector(Parameter_Pointer_Function &ppf){
  PetscErrorCode ierr;
  Vec initialvec; 
  ierr=VecCreate(PETSC_COMM_WORLD,&initialvec);CHKERRQ(ierr);
  ierr=VecSetSizes(initialvec,PETSC_DECIDE,ppf.get_DIM());CHKERRQ(ierr);
  ierr=VecSetFromOptions(initialvec);CHKERRQ(ierr);

  double *ptr;
  ierr=VecGetArray(initialvec,(PetscScalar **)&ptr);CHKERRQ(ierr);
  ppf.get_params(ptr);

  ierr=VecRestoreArray(initialvec,(PetscScalar **)&ptr);CHKERRQ(ierr);
  ierr=TaoSetInitialVector(tao,initialvec);CHKERRQ(ierr);
  ierr=VecDestroy(&initialvec);CHKERRQ(ierr);
  return ierr;
}
  void minimize(Parameter_Pointer_Function &ppf){
    Set_Initial_Vector(ppf);   
    TaoSetObjectiveRoutine(tao, Tao_Minimizer::Objective_Function, (void*)&ppf);

    TaoSolve(tao);
  }
  Tao_Minimizer(Parameter_Map &param_map_){
    param_map=&param_map_;
    PetscInitialize(param_map->p_args,param_map->p_argv,(char*)0,0);
    TaoCreate(PETSC_COMM_WORLD,&tao);
    TaoSetType(tao, TAONM);
    TaoSetFromOptions(tao);
    PetscViewer monviewer;
    PetscViewerASCIIOpen(PETSC_COMM_WORLD,"stdout",&monviewer);
    TaoSetMonitor(tao,TaoMonitorDefault,monviewer,(PetscErrorCode (*)(void**))PetscViewerDestroy);

  }
  ~Tao_Minimizer(){
    TaoDestroy(&tao);
    SLEPc_Register_Parameter_Map(*param_map);
    PetscFinalize();
  }
};


#endif