//+------------------------------------------------------------------+
//|                                      LinearRegressionChannel.mq4 |
//|                                                           dimicr |
//|                                         http://www.signalsbg.com |
//|      SignalsBG.com - development of trading tools for Metatrader |
//////////////////////////////////////////////////////////////////////
#property copyright "Copyright © 2008 signalsbg.com"
#property link      "http://www.signalsbg.com"
#property indicator_chart_window

#property indicator_buffers 3
#property indicator_width1 1
#property indicator_width2 1
#property indicator_width3 1
#property indicator_color1 Gold
#property indicator_color2 Aqua
#property indicator_color3 OrangeRed

extern bool UseClose = true;
extern int  barsToCount=50;

double LR_line[];
double Sup_line[];
double Res_line[];

//////////////////////////////////////////////////////////////////////
int init()
{
   //IndicatorShortName("LinearRegressionChannel:"+barsToCount);
   SetIndexStyle(0,DRAW_LINE);
   SetIndexBuffer(0,LR_line);
   SetIndexEmptyValue(0,0.0);
   
   SetIndexStyle(1,DRAW_LINE);
   SetIndexBuffer(1,Sup_line);
   SetIndexEmptyValue(1,0.0);
   
   SetIndexStyle(2,DRAW_LINE);
   SetIndexBuffer(2,Res_line);
   SetIndexEmptyValue(2,0.0);
   
   
   return(0);
}

//////////////////////////////////////////////////////////////////////
int deinit()
{  
   return(0);
}

//////////////////////////////////////////////////////////////////////
int start()
{
   // variables
   double a,b,c,
          sumy=0.0,
          sumx=0.0,
          sumxy=0.0,
          sumx2=0.0,
          h=0.0,l=0.0;   
   int x;
   
   // calculate linear regression
   
   for(int i=0; i<barsToCount; i++)
   {
      sumy+=Close[i];
      sumxy+=Close[i]*i;
      sumx+=i;
      sumx2+=i*i;
   }
   
   c=sumx2*barsToCount-sumx*sumx;
   
   if(c==0.0)
   {
      Alert("Error in linear regression!");
      return;
   }
   
   
   // Line equation    
   b=(sumxy*barsToCount-sumx*sumy)/c;
   a=(sumy-sumx*b)/barsToCount;
   
   // Linear regression line in buffer
   for(x=0;x<barsToCount;x++)
      LR_line[x]=a+b*x;
   
   

   
   // Use PRICE_CLOSE for support-resistance
   if (UseClose)
     for(x=0;x<barsToCount;x++)
     {
       if(Close[x]-LR_line[x] > h) h = Close[x]-LR_line[x];
       if(LR_line[x] - Close[x]> l) l = LR_line[x] - Close[x];
     }  
   
   // Use HIGH - LOW
   else
     for(x=0;x<barsToCount;x++)
     {
       if(High[x]-LR_line[x] > h) h = High[x]-LR_line[x];
       if(LR_line[x] - Low[x]> l) l = LR_line[x] - Low[x];
     }
   
   // Drawing support - resistance lines   
   if (h>l)
   {
     for(x=0;x<barsToCount;x++)
     {
       Sup_line[x]=a-h+b*x;
       Res_line[x]=a+h+b*x;
     } 
   }
   else
   {
     for(x=0;x<barsToCount;x++)
     {
       Sup_line[x]=a-l+b*x;
       Res_line[x]=a+l+b*x;
     }
   }
   
   LR_line[x]  = 0.0;
   Sup_line[x] = 0.0;
   Res_line[x] = 0.0;

   return(0);
}