Code: Select all

#property indicator_chart_window
#property indicator_buffers 1

#property indicator_color1 Red
//---- input parameters
extern double       LongPeriod=25.0;  // note that for an EMA you can have floating point numbers. 
extern double       ShortPeriod=8.0;
extern double       ExtraTimeForward=1.0; // how much to further extrapolate location. 

//---- buffers
//---- indicator buffers
double ExtBuffer[];

//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int init()
  {

   SetIndexBuffer(0,ExtBuffer);
 //---- drawing settings
   SetIndexStyle(0,DRAW_LINE);
//---- initialization done
   return(0);
  }


int start()
  {
   int limit;
   int counted_bars=IndicatorCounted();
   double ma1,ma3;
   double p1,p3; 
   double t1,t3,t;

//---- check for possible errors
   if(counted_bars<0) return(-1);
//---- last counted bar will be recounted
   if(counted_bars>0) counted_bars--;
    limit=MathMin(Bars-counted_bars,Bars-1);
   
//---- main loop
   p1 = 2.0/(LongPeriod+1.0);
   p3 = 2.0/(ShortPeriod+1.0); 
   
   t1 = (LongPeriod-1.0)/2.0;
   t3 = (ShortPeriod-1.0)/2.0;
   t = ShortPeriod + ExtraTimeForward;
   
   ma1 = Close[limit-1];
   ma3 = ma1;
   for(int i=limit-1; i>= 0; i--) {
      //---- ma_shift set to 0 because SetIndexShift called abowe
      double val = Close[i];
      double slope1, predict;

         
      ma1 = p1*val + (1.0-p1)*ma1;
      ma3 = p3*val + (1.0-p3)*ma3;
      
      slope1 = (ma3-ma1)/(t1-t3);
   
      predict = ma3 + slope1*t;
   
      ExtBuffer[i]=predict; 
  }
//---- done
   return(0);
}
//+------------------------------------------------------------------+