//+------------------------------------------------------------------+
//|                                                 forecast osc.mq4 |
//|                Copyright © 2005, Nick Bilak, beluck[AT]gmail.com |
//|                                    http://metatrader.50webs.com/ |
//+------------------------------------------------------------------+
#property copyright "Copyright © 2005, Nick Bilak"
#property link      "http://metatrader.50webs.com/"

#property indicator_separate_window
#property indicator_buffers 4
#property indicator_level1 0
#property indicator_color1 SteelBlue
#property indicator_color2 HotPink
#property indicator_color3 Magenta
#property indicator_color4 Aqua

//---- input parameters
extern int       regress=15;
extern int       t3=3;
extern double    b=0.7;

//---- buffers
double osc[];
double osct3[];
double hiSig[];
double loSig[];

int shift,limit,length;
double b2,b3,c1,c2,c3,c4,w1,w2,n,WT,forecastosc,t3_fosc,sum,e1,e2,e3,e4,e5,e6,tmp,tmp2;

//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int init()
  {
//---- indicators
//   SetIndexStyle(0,DRAW_HISTOGRAM);
   SetIndexStyle(0,DRAW_LINE);
   SetIndexBuffer(0,osc);
   SetIndexEmptyValue(0,0);
   
   SetIndexStyle(1,DRAW_LINE);
   SetIndexBuffer(1,osct3);

   SetIndexStyle(2,DRAW_ARROW);
   SetIndexBuffer(2,hiSig);
   SetIndexEmptyValue(2,EMPTY_VALUE);
   SetIndexArrow(2,159);
   
   SetIndexStyle(3,DRAW_ARROW);
   SetIndexBuffer(3,loSig);
   SetIndexEmptyValue(3,EMPTY_VALUE);
   SetIndexArrow(3,159);
//----
   return(0);
  }
//+------------------------------------------------------------------+
//| Custor indicator deinitialization function                       |
//+------------------------------------------------------------------+
int deinit()
  {
   return(0);
  }
//+------------------------------------------------------------------+
//| Custom indicator iteration function                              |
//+------------------------------------------------------------------+
int start()
  {
   int counted_bars=IndicatorCounted();
   
   if (counted_bars<0) return(-1);
   if (counted_bars>0) counted_bars--;
   limit=Bars-31;
   if(counted_bars>=31) limit=Bars-counted_bars+2;

   for (shift=limit+30;shift>=0;shift--)   {

      b2=b*b; 
      b3=b2*b; 
      c1=-b3; 
      c2=(3*(b2+b3)); 
      c3=-3*(2*b2+b+b3); 
      c4=(1+3*b+b3+3*b2); 
      n=t3; 

      if (n<1) n=1; 
      n = 1 + 0.5*(n-1); 
      w1 = 2 / (n + 1); 
      w2 = 1 - w1; 

      length=regress; 
      sum = 0; 
      for (int i = length; i>0; i--) {
         tmp = length+1;
         tmp = tmp/3;
         tmp2 = i;
         tmp = tmp2 - tmp;
         sum = sum + tmp*Close[shift+length-i]; 
      }
      tmp = length;
      WT = sum*6/(tmp*(tmp+1)); 

      forecastosc=(Close[shift]-WT)/WT*100; 

      e1 = w1*forecastosc + w2*e1; 
      e2 = w1*e1 + w2*e2; 
      e3 = w1*e2 + w2*e3; 
      e4 = w1*e3 + w2*e4; 
      e5 = w1*e4 + w2*e5; 
      e6 = w1*e5 + w2*e6; 

      t3_fosc = c1*e6 + c2*e5 + c3*e4 + c4*e3; 

      osc[shift] = forecastosc;
      osct3[shift] = t3_fosc;
      
      if (osc[shift+1] > osct3[shift+2] && osc[shift+2] <= osct3[shift+3] && osct3[shift+1]<0) loSig[shift+1] = t3_fosc-0.05;
      if (osc[shift+1] < osct3[shift+2] && osc[shift+2] >= osct3[shift+3] && osct3[shift+1]>0) hiSig[shift+1] = t3_fosc+0.05;

   }
   return(0);
  }
//+------------------------------------------------------------------+