/***************************************************************************
                 module classe tb.h  -  description
***************************************************************************/
// Mohamed Berrada
// locean-ipsl.upmc, Paris, April 2, 2009
//===========================================================================
//                          methode forward
forward (YREAL x1,YREAL x2,YREAL x3,YREAL x4)
{ /*	1	from	tb			1  i 	j    k    t-1
	2	from	ta			1  i 	j    k    t-1
	3	from	ta			1  i 	j    k    t
	4	from	ta_c			1  i 	j    k     */

  if(Yt==TU){
#ifdef YE_ta_c
    if( ndiag_rst==0)
      YS1=x4;
    else{
      if( neuler == 0)
	YS1=x4;
      else 
	YS1=tb_neuler1(Yi,Yj,Yk);
    }
#else
    if( neuler == 0)//   ! Euler 1st time step : swap only
      YS1=x4;
    else
      YS1=tb_neuler1(Yi,Yj,Yk); // valeur chargee depuis restart (neuler=1)
#endif
  }
  else{
    if(Yk!=NZ-1){
#ifdef YE_ta_c
      if( Yt == TU+1 && ndiag_rst == 0)//   ! Euler 1st time step : swap only
#else
      if( Yt == TU+1 && neuler == 0)//   ! Euler 1st time step : swap only
#endif
	YS1=x2;
      else
	YS1 = atfp*(x1+x3)+atfp1*x2;
      // pour generer le tourbillon
      /*  YS1=YS1+exp(-((Yi+1.-(3.*NX)/4.)*(Yi+1.-(3.*NX)/4.)+ 
	  (Yj+1.-(3.*NY)/4.)*(Yj+1.-(3.*NY)/4.))/4.)
	  *(1.-exp(-double(Yk+1.-NZ)/NZ))*(1.-exp(-double(Yt-TU)/24.));*/
#ifdef EDDY
      if (Yt<27)
      //pour generer un tourbillon à Yi=19 et Yj=13
      YS1=YS1+4*exp(-0.75*((Yi - 17.*(NX/32.))*(Yi - 17.*(NX/32.))+ 
		    (Yj - 10.*(NY/22.))*(Yj - 10.*(NY/22.))))
	*(1.-exp(-double(Yk+1.-NZ)/NZ))*(1.-exp(-double(Yt-TU)/24.));
#endif
	}
  }
  //
}
    //===========================================================================
    //                         methode  backward

backward (YREAL x1,YREAL x2,YREAL x3,YREAL x4)
{
  YJ1I1=0.;     YJ1I2=0.;   YJ1I3=0.;     YJ1I4=0.;
  if(Yt==TU){
    //YJ1I1=0.;     YJ1I2=0.;   YJ1I3=0.;  YJ1I4=0.;  
#ifdef YE_ta_c
    //if(Yi==28 && Yj==12) 
    YJ1I4=1.;
#else
    if( neuler == 0)//   ! Euler 1st time step : swap only
      YJ1I4=1.;//
    else
       YJ1I4=0.;//
#endif
  }
  else{
    if(Yk!=NZ-1){
#ifdef YE_ta_c
      if( Yt == TU+1){//   ! Euler 1st time step : swap only
	  YJ1I1=0.;     YJ1I2=1.;   YJ1I3=0.;     YJ1I4=0.;
      }
#else
	if( Yt == TU+1 && neuler == 0){//   ! Euler 1st time step : swap only
	  YJ1I1=0.;     YJ1I2=1.;   YJ1I3=0.;     YJ1I4=0.;
      }
#endif
      else{
	YJ1I1 =  atfp;
	YJ1I2 =  atfp1;
	YJ1I3 =  atfp;
	YJ1I4 =  0.;
      }
    }
  }
  //
}

//===========================================================================
//***************************  FIN DU MODULE tb   ***************************