//+------------------------------------------------------------------+
//|                                                        Vidya.mq4 |
//|                                  Copyright © 2006, Amritend Maji |
//+------------------------------------------------------------------+
#property copyright "Copyright © 2006, Amritendu Maji"
#property link      "None"

//---- indicator settings
#property  indicator_chart_window
#property  indicator_buffers 1
#property  indicator_color1  Black
#property  indicator_width1  1

//---- indicator parameters
extern int Periods=21;
extern double SmoothConst=9;

//---- indicator buffers
double e0[];
double e1[];

double SC;

//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int init()
  {
   IndicatorBuffers(2);
//---- drawing settings
   SetIndexStyle(0,DRAW_LINE);
   SetIndexDrawBegin(0,Periods);
   if(
   	!SetIndexBuffer(0,e0) &&
      !SetIndexBuffer(1,e1) 
      )
      Print("cannot set indicator buffers!");
//---- name for DataWindow and indicator subwindow label
   IndicatorShortName("VIDYA("+Periods+")");

   	SC = 2/(SmoothConst+1);
//---- initialization done
   return(0);
   
  }
  
//+------------------------------------------------------------------+
//| Moving Average                                                   |
//+------------------------------------------------------------------+
int start()
  {
   int i,j,limit;
   double day, upday, downday;
   int counted_bars=IndicatorCounted();
   
//---- check for possible errors
   if(counted_bars<0) return(-1);
   
//---- last counted bar will be recounted
   if(counted_bars > 0) counted_bars --;
   if (counted_bars == 0) limit = Bars - Periods;
   else limit = Bars-counted_bars;

//---- main loop
   for(i=limit; i>=0; i--) 
   {
     upday = 0;
     downday = 0;
     for (j=0; j<Periods; j++)
     {
      day = Close[i+j]- Close[i+j+1];
      if(day > 0) upday += day;
      if(day < 0) downday -= day;
     }
      e1[i] = MathAbs((upday-downday)/(upday+downday)); 
      e0[i]= SC*e1[i]*Close[i] + (1-SC*e1[i])*e0[i+1]; 
   }
//---- done
   return(0);
  }
  
//+------------------------------------------------------------------+