//+------------------------------------------------------------------+
//|                                            KG Monthly BB 3SD.mq4 |
//|                      Copyright © 2008, MetaQuotes Software Corp. |
//|                                       http://www.metaquotes.net/ |
//+------------------------------------------------------------------+
#property copyright "Copyright © 2008, MetaQuotes Software Corp."
#property link      "http://www.metaquotes.net/"

#property indicator_chart_window
#property indicator_buffers 7
#property indicator_color1 Aqua
#property indicator_color2 Aqua
#property indicator_color3 Aqua
#property indicator_color4 Aqua
#property indicator_color5 Aqua
#property indicator_color6 Aqua
#property indicator_color7 Aqua
//---- indicator parameters
int    BandsPeriod=20;
extern int MA_Mode=MODE_SMA;
int    BandsShift=0;
extern double BandsDeviations_1=1.0;
extern double BandsDeviations_2=2.0;
extern double BandsDeviations_3=3.0;
extern int Price_Type=0;
//---- buffers
double MovingBuffer[];
double UpperBuffer[];
double LowerBuffer[];
double UpperBuffer1[];
double LowerBuffer1[];
double UpperBuffer2[];
double LowerBuffer2[];
//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int init()
  {
//---- indicators
   SetIndexStyle(0,DRAW_LINE, 0,2);
   SetIndexBuffer(0,MovingBuffer);
   SetIndexStyle(1,DRAW_LINE, STYLE_DOT,1);
   SetIndexBuffer(1,UpperBuffer);
   SetIndexStyle(2,DRAW_LINE, STYLE_DOT,1);
   SetIndexBuffer(2,LowerBuffer);
   SetIndexStyle(3,DRAW_LINE, STYLE_DOT,1);
   SetIndexBuffer(3,UpperBuffer1);
   SetIndexStyle(4,DRAW_LINE, STYLE_DOT,1);
   SetIndexBuffer(4,LowerBuffer1);
   SetIndexStyle(5,DRAW_LINE, STYLE_DOT,1);
   SetIndexBuffer(5,UpperBuffer2);
   SetIndexStyle(6,DRAW_LINE, STYLE_DOT,1);
   SetIndexBuffer(6,LowerBuffer2);
   
  
//----
   SetIndexDrawBegin(0,BandsPeriod+BandsShift);
   SetIndexDrawBegin(1,BandsPeriod+BandsShift);
   SetIndexDrawBegin(2,BandsPeriod+BandsShift);
   SetIndexDrawBegin(3,BandsPeriod+BandsShift);
   SetIndexDrawBegin(4,BandsPeriod+BandsShift);
   SetIndexDrawBegin(5,BandsPeriod+BandsShift);
   SetIndexDrawBegin(6,BandsPeriod+BandsShift);
//----
   getPeriod();
   return(0);
  }
//+------------------------------------------------------------------+
//| Bollinger Bands                                                  |
//+------------------------------------------------------------------+
int start()
  {
   int    i,k,counted_bars=IndicatorCounted();
   double deviation,deviation1,deviation2;
   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,MA_Mode,Price_Type,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=BandsDeviations_1*MathSqrt(sum/BandsPeriod);
      deviation1=BandsDeviations_2*MathSqrt(sum/BandsPeriod);
      deviation2=BandsDeviations_3*MathSqrt(sum/BandsPeriod);
      UpperBuffer[i]=oldval+deviation;
      LowerBuffer[i]=oldval-deviation;
      UpperBuffer1[i]=oldval+deviation1;
      LowerBuffer1[i]=oldval-deviation1;
      UpperBuffer2[i]=oldval+deviation2;
      LowerBuffer2[i]=oldval-deviation2;
      i--;
     }
//----
   return(0);
  }
//+------------------------------------------------------------------+

void getPeriod()
{
   switch(Period()) 
      {
         case 1: 
            BandsPeriod=28800;
            break;
         case 5: 
            BandsPeriod=5760;
            break;
         case 15: 
            BandsPeriod=1920;
            break;
         case 30: 
            BandsPeriod=960;
            break;
         case 60: 
            BandsPeriod=480;
            break;
         case 240: 
            BandsPeriod=120;
            break;
         case 1440: 
            BandsPeriod=20;
            break;
         case 10080: 
            BandsPeriod=2;
            break;
         case 43200: 
            BandsPeriod=0;
            break;
         
      }
 }