//+------------------------------------------------------------------+
//|                                                3rd Generation MA |
//|                                      Copyright © 2011, EarnForex |
//|                                        http://www.earnforex.com/ |
//+------------------------------------------------------------------+
#property copyright "Copyright © 2011, EarnForex"
#property link      "http://www.earnforex.com"
/*

3rd Generation MA based on research paper by Dr. Mafred Durschner:
http://www.vtad.de/node/1441 (in German)
Offers least possible lag but still provides price smoothing

*/
#property indicator_chart_window
#property indicator_buffers 2
#property indicator_color1 Red 
#property indicator_color2 Blue 
//---- indicator parameters
extern int MA_Period=220;
extern int MA_Sampling_Period=50; // Sampling period should be less than 1/4 of MA_Period
extern int MA_Method=1; //0 - SMA, 1 - EMA, 2 - SMMA, 3 - LWMA
extern int MA_Applied_Price=5; // 0 - PRICE_CLOSE, 1 - PRICE_OPEN, 2 - PRICE_HIGH, 3 - PRICE_LOW, 4 - PRICE_MEDIAN, 5 - PRICE_TYPICAL, 6 - PRICE_WEIGHTED
//---- indicator buffers
double MA3G[];
double MA1[];
//----
double Lambda,Alpha;
//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int init()
  {
   int    draw_begin;
   string short_name;
//---
   IndicatorBuffers(3);
//---- drawing settings
   SetIndexStyle(0,DRAW_LINE);
   IndicatorDigits(MarketInfo(Symbol(),MODE_DIGITS));
//---
   draw_begin=MA_Period-1;
//---- indicator short name
   switch(MA_Method)
     {
      case 1:
         short_name="3GEMA(";
         draw_begin=0;
         break;
      case 2:
         short_name="3GSMMA(";
         break;
      case 3:
         short_name="3GLWMA(";
         break;
      default:
         MA_Method=0;
         short_name="3GSMA(";
     }
   IndicatorShortName(short_name+MA_Period+")");
//---
   SetIndexDrawBegin(0,draw_begin);
//---- indicator buffers mapping
   SetIndexBuffer(0,MA3G);
   SetIndexBuffer(1,MA1);
//---
   Lambda= 1.0 * MA_Period/(1.0 * MA_Sampling_Period);
   Alpha = Lambda *(MA_Period-1)/(MA_Period-Lambda);
//---
   Print("Lambda = ",Lambda,"; Alpha = ",Alpha);
//---- initialization done
   return(0);
  }
//+------------------------------------------------------------------+
//| 3rd Generation Moving Average Custom Indicator                   |
//+------------------------------------------------------------------+
int start()
  {
   int i;
//---
   if(MA_Period*2<MA_Sampling_Period)
     {
      Print("MA_Period should be >= MA_Sampling_Period * 2.");
      return(-1);
     }
   if(Bars <= MA_Period) return(0);
   int ExtCountedBars=IndicatorCounted();
//---- check for possible errors
   if(ExtCountedBars < 0) return(-1);
//---- last counted bar will be recounted
   if(ExtCountedBars>0) ExtCountedBars--;
   if(ExtCountedBars<MA_Period) ExtCountedBars=MA_Period;
//----
   for(i=Bars-ExtCountedBars-1; i>=0; i--)
      MA1[i]=iMA(NULL,0,MA_Period,0,MA_Method,MA_Applied_Price,i);
//---
   for(i=Bars-ExtCountedBars-1; i>=0; i--)
     {
      double MA2=iMAOnArray(MA1,0,MA_Sampling_Period,0,MA_Method,i);
      MA3G[i]=(Alpha+1)*MA1[i]-Alpha*MA2;
     }
//---- done
   return(0);
  }
//+------------------------------------------------------------------+