//+------------------------------------------------------------------+
//|                                                      BB_MACD.mq4 |
//|                                     Copyright © 2005, adoleh2000 |
//|                                       http://www.metaquotes.net/ |
//+------------------------------------------------------------------+
#property  copyright "Copyright © 2005, adoleh2000"
#property  link      "http://www.metaquotes.net/"
//---- indicator settings
#property  indicator_separate_window
#property  indicator_buffers 4
#property  indicator_color1  Lime    //bbMacd up
#property  indicator_color2  Magenta //bbMacd down
#property  indicator_color3  Blue    //Upperband
#property  indicator_color4  Red     //Lowerband
//---- indicator parameters
extern int FastLen = 12;
extern int SlowLen = 26;
extern int Length = 9;
extern double StDv = 2.5;
extern int BarsAmount = 200;
//---- indicator buffers
double ExtMapBuffer1[];  // bbMacd up
double ExtMapBuffer2[];  // bbMacd down
double ExtMapBuffer3[];  // Upperband Line
double ExtMapBuffer4[];  // Lowerband Line
//---- buffers
double bbMacd[];
double avg;
double sDev;
//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int init()
  {
//---- 1 additional buffers are used for counting.
   IndicatorBuffers(5);   
//---- drawing settings     
   SetIndexBuffer(0, ExtMapBuffer1); // bbMacd up line
   SetIndexStyle(0, DRAW_ARROW);
   SetIndexArrow(0, 159);
   IndicatorDigits(Digits + 1);
//----
   SetIndexBuffer(1, ExtMapBuffer2); // bbMacd down line
   SetIndexStyle(1, DRAW_ARROW);
   SetIndexArrow(1, 159);
   IndicatorDigits(Digits + 1);
//----   
   SetIndexBuffer(2, ExtMapBuffer3); // Upperband line
   SetIndexStyle(2, DRAW_LINE, STYLE_SOLID, 1);
   IndicatorDigits(Digits + 1);
//----   
   SetIndexBuffer(3, ExtMapBuffer4); // Lowerband line
   SetIndexStyle(3, DRAW_LINE, STYLE_SOLID, 1);
   IndicatorDigits(Digits + 1);
//----
   SetIndexBuffer(4, bbMacd);
//---- name for DataWindow and indicator subwindow label
   IndicatorShortName("BB MACD(" + FastLen + "," + SlowLen + "," + Length+")");
   SetIndexLabel(0, "bbMacdUp");
   SetIndexLabel(1, "bbMacdDn");
   SetIndexLabel(2, "Upperband");
   SetIndexLabel(3, "Lowerband");
//----
   SetIndexDrawBegin(0, Bars - BarsAmount - 1);
   SetIndexDrawBegin(1, Bars - BarsAmount - 1);   
   SetIndexDrawBegin(2, Bars - BarsAmount - 1);
   SetIndexDrawBegin(3, Bars - BarsAmount - 1);       
//---- initialization done
   return(0);
  }
//+------------------------------------------------------------------+
//| Custor indicator deinitialization function                       |
//+------------------------------------------------------------------+
int deinit()
  {
//----
   return(0);
  }
//+------------------------------------------------------------------+
//| Custom BB_MACD                                                   |
//+------------------------------------------------------------------+
int start()
  {
   int limit;
   if(Bars < MathMax(FastLen, MathMax(SlowLen, Length)))
       return(-1);       
   if(Bars < BarsAmount)
       BarsAmount = Bars;       
   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--;
   limit = Bars - counted_bars;
//----
   for(int i = 0; i < limit; i++)
       bbMacd[i] = iMA(NULL, 0, FastLen, 0, MODE_EMA, PRICE_CLOSE, i) - 
                   iMA(NULL, 0, SlowLen, 0, MODE_EMA, PRICE_CLOSE, i);
//----
   for(i = 0; i < BarsAmount; i++)
     {
       avg = iMAOnArray(bbMacd, 0, Length, 0, MODE_EMA, i);
       sDev = iStdDevOnArray(bbMacd, 0, Length, 0, MODE_EMA, i);
       ExtMapBuffer3[i] = avg + (StDv * sDev);  // Upperband 
       ExtMapBuffer4[i] = avg - (StDv * sDev);  // Lowerband
       //----
       if(bbMacd[i] > bbMacd[i+1])
         {
           ExtMapBuffer1[i]=bbMacd[i];  // Uptrend bbMacd
           ExtMapBuffer2[i] = EMPTY_VALUE;
         }
       //----
       if(bbMacd[i] < bbMacd[i+1])
         {
           ExtMapBuffer2[i]=bbMacd[i];     // Downtrend bbMacd       
           ExtMapBuffer1[i] = EMPTY_VALUE;
         }
     }
//---- done
   return(0);
  }
//+------------------------------------------------------------------+