/*
 * $Id: fvar_a33.cpp 494 2012-06-13 20:41:16Z johnoel $
 *
 * Author: David Fournier
 * Copyright (c) 2008-2012 Regents of the University of California 
 */
/**
 * \file
 * Description not yet available.
 */
#include "fvar.hpp"

  void DF_dv_dble_div(void);

/**
 * Description not yet available.
 * \param
 */
dvar_vector operator/(const dvar_vector& t1, const prevariable& x)
  {
    RETURN_ARRAYS_INCREMENT();
    dvar_vector tmp(t1.indexmin(),t1.indexmax());
    save_identifier_string("ccbb");
    x.save_prevariable_value();
    x.save_prevariable_position();
    for (int i=t1.indexmin(); i<=t1.indexmax(); i++)
    {
      tmp.elem_value(i)=t1.elem_value(i)/value(x);
    }
    tmp.save_dvar_vector_value();
    tmp.save_dvar_vector_position();
    t1.save_dvar_vector_position();
    save_identifier_string("ddaa");
    RETURN_ARRAYS_DECREMENT();
    gradient_structure::GRAD_STACK1->
	    set_gradient_stack(DF_dv_dble_div);
    return(tmp);
  }

/**
 * Description not yet available.
 * \param
 */
 void DF_dv_dble_div(void)
 {
    verify_identifier_string("ddaa");
    dvar_vector_position t1_pos=restore_dvar_vector_position();
    dvar_vector_position tmp_pos=restore_dvar_vector_position();
    dvector tmp=restore_dvar_vector_value(tmp_pos);
    prevariable_position xpos=restore_prevariable_position();
    double x=restore_prevariable_value();
    dvector dftmp=restore_dvar_vector_derivatives(tmp_pos);
    dvector dft1(t1_pos.indexmin(),t1_pos.indexmax());
    verify_identifier_string("ccbb");
    double xinv=1./x;
    double dfx=0.;
    for (int i=t1_pos.indexmax(); i>=t1_pos.indexmin(); i--)
    {
      //tmp.elem_value(i)=value(x)*t1.elem_value(i)/value(x);
      dfx-=dftmp(i)*tmp(i)*xinv;
      dft1(i)=dftmp(i)*xinv;
    }
    save_double_derivative(dfx,xpos);
    dft1.save_dvector_derivatives(t1_pos);
 }
