//+------------------------------------------------------------------+
//|                                                 i-BandsPrice.mq4 |
//|                                          Copyright © 2008, Talex |
//|                                                 tan@gazinter.net |
//+------------------------------------------------------------------+
#property copyright "Copyright © 2008, Talex"
#property link      "tan@gazinter.net"

#property indicator_separate_window
#property indicator_buffers 1
#property indicator_color1 Yellow
#property indicator_level1 0
#property indicator_level2 0.25
#property indicator_level3 0.5
#property indicator_level4 0.75
#property indicator_level5 1

extern int    BandsPeriod=20;
extern int    BandsShift=0;
extern double BandsDeviations=2.0;
extern int    Slow=5;

double BPBuffer[],Buffer[];
//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
void init() {
   
   IndicatorBuffers(2);
   IndicatorShortName("i-BandsPrice ("+BandsPeriod+", "+DoubleToStr(BandsDeviations,1)+", "+Slow+")");
   SetIndexStyle(0,DRAW_LINE);
   SetIndexBuffer(0,Buffer);
   SetIndexBuffer(1,BPBuffer);
   
   return;
}
//+------------------------------------------------------------------+
//| Custom indicator deinitialization function                       |
//+------------------------------------------------------------------+
void deinit() {

   return;
}
//+------------------------------------------------------------------+
//| Custom indicator iteration function                              |
//+------------------------------------------------------------------+
void start() {
   int i,j,limit,cbars;
   double sum,oldval,newres,deviation,upband,dwband;
   
   cbars=IndicatorCounted();
   if(Bars<=BandsPeriod) return;
   if(cbars<0) return;
   if(cbars>0) limit=Bars-cbars-1;
      else limit=Bars-BandsPeriod-1;

   for(i=0;i<=limit;i++) {
      sum=0.0;
      oldval=iMA(NULL,0,BandsPeriod,BandsShift,MODE_SMA,PRICE_CLOSE,i);
      for(j=0;j<BandsPeriod;j++) {
         newres=Close[i+j]-oldval;
         sum+=newres*newres;
      }
      deviation=BandsDeviations*MathSqrt(sum/BandsPeriod);
      upband=oldval+deviation;
      dwband=oldval-deviation;
      if((upband-dwband)!=0)
      BPBuffer[i]=(Close[i]-dwband)/(upband-dwband);
   }
   for(i=0;i<=limit;i++) {
      Buffer[i]=iMAOnArray(BPBuffer,0,Slow,0,0,i);
   }
   return;
}
//+------------------------------------------------------------------+