#property copyright ""
#property link      ""
#define major   1
#define minor   0
#property indicator_chart_window
#property indicator_buffers 4
#property indicator_color1 Red
#property indicator_color2 Yellow
#property indicator_width1  1
#property indicator_width2  1
 
extern int FrPeriod = 10;
extern int MaxBars = 500;
double ldata ,udata;
double upper_fr[];
double lower_fr[];
double upper_data[];
double lower_data[];
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
void init() {
  SetIndexBuffer(0, upper_fr);
  SetIndexBuffer(1, lower_fr);
  SetIndexBuffer(2,upper_data);
  SetIndexBuffer(3,lower_data);
  
  SetIndexLabel(2,"upper data");
  SetIndexLabel(3,"lower data");
  
  SetIndexEmptyValue(0, 0);
  SetIndexEmptyValue(1, 0);
  
  SetIndexStyle(0, DRAW_ARROW);
  SetIndexArrow(0, 234);
  SetIndexStyle(1, DRAW_ARROW);
  SetIndexArrow(1, 233); 
   
  
  
}
void start()
{
  int counted = IndicatorCounted();
  if (counted < 0) return (-1);
  if (counted > 0) counted--;
  
  int limit = MathMin(Bars-counted, MaxBars);
  
  //-----
  
  double dy = 0;
  for (int i=1; i <= 20; i++) {
    dy += 0.3*(High[i]-Low[i])/20;
  }
  
  for (i=limit+FrPeriod; i >= 0; i--)
  {
    upper_fr[i] = 0;
    lower_fr[i] = 0;
    upper_data[i] = 0;
    lower_data[i] = 0;
  
    if (is_upper_fr(i, FrPeriod))
      {
      upper_fr[i] = High[i]+dy;
      udata= High[i]+dy;
      }
    if (is_lower_fr(i, FrPeriod))
      {
      lower_fr[i] = Low[i]-dy;
      ldata = Low[i]-dy;
      }
    lower_data[i]=ldata;
    upper_data[i]=udata;
  }
}
bool is_upper_fr(int bar, int period)
{
  for (int i=1; i<=period; i++)
  {
    if (bar+i >= Bars || bar-i < 0) return (false);
    if (High[bar] < High[bar+i]) return (false);
    if (High[bar] < High[bar-i]) return (false);
  }
  
  return (true);
}
bool is_lower_fr(int bar, int period)
{
  for (int i=1; i<=period; i++)
  {
    if (bar+i >= Bars || bar-i < 0) return (false);
    
    if (Low[bar] > Low[bar+i]) return (false);
    if (Low[bar] > Low[bar-i]) return (false);
  }
  
  return (true);
}