StarcBands

//+------------------------------------------------------------------+
//|                                                   StarcBands.mq4 |
//|                      Copyright © 2005, MetaQuotes Software Corp. |
//|                                       http://www.metaquotes.net/ |
//|                                                    Linuxser 2007 |
//+------------------------------------------------------------------+
#property copyright "Copyright © 2005, MetaQuotes Software Corp."
#property link      "http://www.metaquotes.net/"
//----
#property indicator_chart_window
#property indicator_buffers 3
#property indicator_color1 Purple
#property indicator_color2 Blue
#property indicator_color3 Red
//---- indicator parameters
extern int    BandsPeriod = 6;
extern int    ATR = 15;
extern double Multiplier = 2.0;
extern int    BandsShift = 0;
//---- buffers
double MovingBuffer[];
double UpperBuffer[];
double LowerBuffer[];
//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int init()
  {
//---- indicators
   SetIndexStyle(0, DRAW_LINE);
   SetIndexBuffer(0, MovingBuffer);
   SetIndexStyle(1, DRAW_LINE);
   SetIndexBuffer(1, UpperBuffer);
   SetIndexStyle(2, DRAW_LINE);
   SetIndexBuffer(2, LowerBuffer);
//----
   SetIndexDrawBegin(0, BandsPeriod + BandsShift);
   SetIndexDrawBegin(1, BandsPeriod + BandsShift);
   SetIndexDrawBegin(2, BandsPeriod + BandsShift);
//----
   return(0);
  }
//+------------------------------------------------------------------+
//| Bollinger Bands                                                  |
//+------------------------------------------------------------------+
int start()
  {
   int i, k, counted_bars = IndicatorCounted();
   double deviation;
   double sum, oldval, newres;
//----
   if(Bars <= BandsPeriod) 
       return(0);
//---- initial zero
   if(counted_bars < 1)
       for(i = 1; i <= BandsPeriod; i++)
         {
           MovingBuffer[Bars-i] = EMPTY_VALUE;
           UpperBuffer[Bars-i] = EMPTY_VALUE;
           LowerBuffer[Bars-i] = EMPTY_VALUE;
         }
//----
   int limit = Bars - counted_bars;
   if(counted_bars > 0) 
       limit++;
   for(i = 0; i < limit; i++)
       MovingBuffer[i] = iMA(NULL, 0, BandsPeriod, BandsShift, 
                             MODE_SMA, PRICE_CLOSE, i);
//----
   i = Bars - BandsPeriod + 1;
   if(counted_bars > BandsPeriod - 1) 
       i = Bars - counted_bars - 1;
   while(i >= 0)
     {
       sum = 0.0;
       k = i + BandsPeriod - 1;
       oldval = MovingBuffer[i];
       while(k >= i)
         {
           newres = Close[k] - oldval;
           sum += newres*newres;
           k--;
         }
       deviation = Multiplier*iATR(NULL, 0, ATR, i); // MathSqrt(sum / BandsPeriod);
       UpperBuffer[i] = oldval + deviation;
       LowerBuffer[i] = oldval - deviation;
       i--;
     }
//----
   return(0);
  }
//+------------------------------------------------------------------+