//+------------------------------------------------------------------+
//|                                            4D - Range Switch.mq4 |
//|                                        Copyright © 2009, Vic2008 |
//|                                                                  |
//+------------------------------------------------------------------+
#property copyright "Copyright © 2009, Vic2008"
#property link      ""

#property indicator_chart_window
#property indicator_buffers 1
#property indicator_color1 Red
//---- buffers
double ExtMapBuffer1[];

double PREV=0;

//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int init()
  {
//---- indicators
   SetIndexStyle(0,DRAW_LINE);
   SetIndexBuffer(0,ExtMapBuffer1);
   
   PREV=0; 
//----
   return(0);
  }
//+------------------------------------------------------------------+
//| Custom indicator deinitialization function                       |
//+------------------------------------------------------------------+
int deinit()
  {
//----
   
//----
   return(0);
  }
//+------------------------------------------------------------------+
//| Custom indicator iteration function                              |
//+------------------------------------------------------------------+
int start()
{
   int i;

for( i=Bars-5; i>=0; i-- ){

   if( Close[i] > MathMax(MathMax(High[i+1],High[i+4]),MathMax(High[i+2],High[i+3]))  ){ ExtMapBuffer1[i]=MathMin(MathMin(Low[i],Low[i+3]),MathMin(Low[i+1],Low[i+2])); }
   else{ 
         if( Close[i] < MathMin(MathMin(Low[i+1],Low[i+4]),MathMin(Low[i+2],Low[i+3])) ){ ExtMapBuffer1[i]=MathMax(MathMax(High[i],High[i+3]),MathMax(High[i+1],High[i+2])); }
         else{  ExtMapBuffer1[i]=PREV; }
       }
   PREV=ExtMapBuffer1[i];
}   
   
   return(0);
}
//+------------------------------------------------------------------+