Dynamic zons by zamansky and

//http://systems4trading.com/formula,487,metastock,dynamic-zones.html
/*
Zamansky & Stendahl's Dynamic Zones for MS6.5 (From the TASC July 1997 article). 
First, for the Lookback Periods plot a 9-day RSI along with StDev adjusted rolling 70-day SMAs; e.g., as can be seen in the article's S&P 500-example. Most indicators use a fixed zone for buy and sell signals.
Here's a concept based on zones that are responsive to past levelsof theindicator.
One approach to active investing employs the use of oscillatorsto exploittradable market trends.
This investing style follows a very simple form of logic: Enter themarket only when an oscillator 
has moved far above or below traditional tradinglevels.
However, these oscillator-driven systems lack the ability to evolvewith the market becausethey use 
fixed buy and sell zones. Traders typically use one set ofbuy andsell zones for a bull marketand 
substantially different zones for a bear market. And therein liestheproblem.

Once traders begin introducing their market opinions into trading equations,by changing the zones, 
they negate the system's mechanical nature. The objective is to havea systemautomatically defineits 
own buy and sell zones and thereby profitably trade in any market-- bullor bear.

Dynamic zones offer a solution to the problem of fixed buy and sellzones for any oscillator-driven system.

The algorithm for the dynamic zones is a series of steps. First, decidethe value of the lookback period t.
Next, decide the value of the probability Pbuy for buy zone and valueof the probability Psell for the sell zone.

The area above and below the dynamic zones constitute the upper andlower10% boundaries.
The zones appear to evolve with the market because they use a rolling70-day period of indicator
 values in their construction.
 



Dynamic Zones 
PR:=Input("Enter Periods for RSI",1,100,9);
PB:=Input("Enter Periods for BUY",1,100,70);
PS:=Input("Enter Periods for SELL",1,100,70);
UpZone:=Mov(RSI(PR),PS,S)+(1.3185 *StDev(RSI(PR),PS));
LwZone:=Mov(RSI(PR),PB,S)-(1.3185 *StDev(RSI(PR),PB));
UpZone;
LwZone;
*/
PR = 9;
PB = 70;
PS = 70;
UPZONE = MA(RSI(PR),70) + (1.3185*StDev(RSI(PR),70));
DNZONE = MA(RSI(PR),70) - (1.3185*StDev(RSI(PR),70));

Plot(RSI(9),"rsi-9",colorBlue,styleThick);
Plot(UPZONE,"UPZONE",colorRed,styleThick);
Plot(DNZONE,"DNZONE",colorBlack,styleThick);

//+------------------------------------------------------------------+
//|                                             Dynamic Zone RSI.mq4 |

//+------------------------------------------------------------------+

#property indicator_buffers 3
#property indicator_color1 Lime
#property indicator_color2 SlateBlue
#property indicator_color3 Orange

#property indicator_separate_window

extern int RSIPeriod = 14;
extern int BandPeriod = 20;

double RSIBuf[],UpZone[],DnZone[];
//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int init()
  {
//---- indicators
   SetIndexStyle(0,DRAW_LINE);
   SetIndexStyle(1,DRAW_LINE);
   SetIndexStyle(2,DRAW_LINE);
   SetIndexBuffer(0,RSIBuf);
   SetIndexBuffer(1,UpZone);
   SetIndexBuffer(2,DnZone);
//----
   return(0);
  }
//+------------------------------------------------------------------+
//| Custor indicator deinitialization function                       |
//+------------------------------------------------------------------+
int deinit()
  {
//---- 
   
//----
   return(0);
  }
//+------------------------------------------------------------------+
//| Custom indicator iteration function                              |
//+------------------------------------------------------------------+
int start()
  {
   double MA, RSI[];
   ArrayResize(RSI,BandPeriod);
   int counted_bars=IndicatorCounted();
   int limit = Bars-counted_bars-1;
   for(int i=limit; i>=0; i--)
   {
      RSIBuf[i] = iRSI(NULL,0,RSIPeriod,PRICE_WEIGHTED,i);
      MA = 0;
      for(int j=i; j<i+BandPeriod; j++) {
         RSI[j-i] = RSIBuf[j];
         MA += RSIBuf[j]/BandPeriod;
      }
      UpZone[i] = MA + (1.3185 * StDev(RSI,BandPeriod));
      DnZone[i] = MA - (1.3185 * StDev(RSI,BandPeriod));  
   }
   
//----
   return(0);
  }
  
double StDev(double& Data[], int Per)
{
  return(MathSqrt(Variance(Data,Per)));
}

double Variance(double& Data[], int Per)
{
  double sum, ssum;
  for (int i=0; i<Per; i++)
  {
    sum += Data[i];
    ssum += MathPow(Data[i],2);
  }
  return((ssum*Per - sum*sum)/(Per*(Per-1)));
}
//+--------------------------------------------