//+------------------------------------------------------------------+
//|                                                  Heiken Ashi.mq4 |
//|                      Copyright c 2004, MetaQuotes Software Corp. |
//|                                        http://www.metaquotes.net |
//+------------------------------------------------------------------+
//| For Heiken Ashi we recommend next chart settings ( press F8 or   |
//| select on menu 'Charts'->'Properties...'):                       |
//|  - On 'Color' Tab select 'Black' for 'Line Graph'                |
//|  - On 'Common' Tab disable 'Chart on Foreground' checkbox and    |
//|    select 'Line Chart' radiobutton                               |
//+------------------------------------------------------------------+
#property copyright "Copyright © 2004, MetaQuotes Software Corp."
#property link      "http://www.metaquotes.net"
//----
#property indicator_chart_window
#property indicator_buffers 4
#property indicator_color1 Red
#property indicator_color2 Green
#property indicator_color3 Red
#property indicator_color4 Green
//----
extern color color1 = Red;
extern color color2 = Green;
extern color color3 = Red;
extern color color4 = Green;
//---- buffers
double ExtMapBuffer1[];
double ExtMapBuffer2[];
double ExtMapBuffer3[];
double ExtMapBuffer4[];
//----
int ExtCountedBars=0;
//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//|------------------------------------------------------------------|
int init()
  {
//---- indicators
   SetIndexStyle(0, DRAW_HISTOGRAM, 0, 2, color1);
   SetIndexBuffer(0, ExtMapBuffer1);
   SetIndexStyle(1, DRAW_HISTOGRAM, 0, 2, color2);
   SetIndexBuffer(1, ExtMapBuffer2);
   SetIndexStyle(2, DRAW_HISTOGRAM, 0, 4, color3);
   SetIndexBuffer(2, ExtMapBuffer3);
   SetIndexStyle(3, DRAW_HISTOGRAM, 0, 4, color4);
   SetIndexBuffer(3, ExtMapBuffer4);
//----
   SetIndexDrawBegin(0, 10);
   SetIndexDrawBegin(1, 10);
   SetIndexDrawBegin(2, 10);
   SetIndexDrawBegin(3, 10);
//---- indicator buffers mapping
   SetIndexBuffer(0, ExtMapBuffer1);
   SetIndexBuffer(1, ExtMapBuffer2);
   SetIndexBuffer(2, ExtMapBuffer3);
   SetIndexBuffer(3, ExtMapBuffer4);
//---- initialization done
   return(0);
  }
//+------------------------------------------------------------------+
//| Custom indicator deinitialization function                       |
//+------------------------------------------------------------------+
int deinit()
  {
//----
   return(0);
  }
//+------------------------------------------------------------------+
//| Custom indicator iteration function                              |
//+------------------------------------------------------------------+
int start()
  {
   double haOpen, haHigh, haLow, haClose;
   if(Bars <= 10) 
       return(0);
   ExtCountedBars = IndicatorCounted();
//---- check for possible errors
   if(ExtCountedBars < 0)        return(-1);
//---- last counted bar will be recounted
   if(ExtCountedBars > 0)        ExtCountedBars--;
   int pos = Bars - ExtCountedBars - 1;
   if(ExtCountedBars==0) pos--;
   while(pos >= 0)
     {
       haOpen = (ExtMapBuffer3[pos+1] + ExtMapBuffer4[pos+1]) / 2;
       haClose = (Open[pos] + High[pos] + Low[pos] + Close[pos]) / 4;
       haHigh = MathMax(High[pos], MathMax(haOpen, haClose));
       haLow = MathMin(Low[pos], MathMin(haOpen, haClose));
       if(haOpen  <haClose) 
         {
           ExtMapBuffer1[pos] = haLow;
           ExtMapBuffer2[pos] = haHigh;
         } 
       else
         {
           ExtMapBuffer1[pos] = haHigh;
           ExtMapBuffer2[pos] = haLow;
         } 
       ExtMapBuffer3[pos] = haOpen;
       ExtMapBuffer4[pos] = haClose;
 	     pos--;
     }
//----
   return(0);
  }
//+------------------------------------------------------------------+