//+------------------------------------------------------------------+
//|                                          EMA_Trend_Indicator.mq4 |
//|                                Copyright © 2006, Robert L Hill   |
//+------------------------------------------------------------------+
// Uses an idea from david to use EMAs to determine trend
#property copyright "Copyright © 2005, Metaquotes"
#property link      "mailto:metaquotes@metaquotes.net"

#property indicator_chart_window
#property indicator_buffers 4
#property indicator_color1 Yellow
#property indicator_color2 Purple
#property indicator_color3 Purple
#property indicator_color4 Yellow
#property indicator_width1 2
#property indicator_width2 2
#property indicator_width3 2
#property indicator_width4 2

//---- input parameters
extern int FastMAPeriod=21;
extern int SlowMAPeriod=34;

//---- buffers
double fastEMA_HighBuffer[];
double fastEMA_LowBuffer[];
double slowEMA_HighBuffer[];
double slowEMA_LowBuffer[];
//---- variables

//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int init()
{
   IndicatorDigits(MarketInfo(Symbol(),MODE_DIGITS)+1);
   //---- indicators
   SetIndexStyle(0,DRAW_LINE);
   SetIndexBuffer(0,slowEMA_HighBuffer);
   SetIndexStyle(1,DRAW_LINE);
   SetIndexBuffer(1,slowEMA_LowBuffer);
   SetIndexStyle(2,DRAW_LINE);
   SetIndexBuffer(2,fastEMA_HighBuffer);
   SetIndexStyle(3,DRAW_LINE);
   SetIndexBuffer(3,fastEMA_LowBuffer);
   SetIndexDrawBegin(0,SlowMAPeriod);
   //---- name for DataWindow and indicator subwindow label
   IndicatorShortName("MA Trend ");
   //----
   return(0);
}
//+------------------------------------------------------------------+
//| Custor indicator deinitialization function                       |
//+------------------------------------------------------------------+
int deinit()
{
   //---- 
   
   //----
   return(0);
}


//+------------------------------------------------------------------+
//| Custom indicator iteration function                              |
//+------------------------------------------------------------------+
int start()
{
   int limit;
   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=limit; i>=0; i--)
   {
     fastEMA_HighBuffer[i] = iMA(NULL,0,FastMAPeriod,0,MODE_EMA,PRICE_HIGH,i);
     fastEMA_LowBuffer[i] = iMA(NULL,0,FastMAPeriod,0,MODE_EMA,PRICE_LOW,i);
     slowEMA_HighBuffer[i] = iMA(NULL,0,SlowMAPeriod,0,MODE_EMA,PRICE_HIGH,i);
     slowEMA_LowBuffer[i] = iMA(NULL,0,SlowMAPeriod,0,MODE_EMA,PRICE_LOW,i);
   }
   
   //----
   return(0);
}
//+------------------------------------------------------------------+