//+------------------------------------------------------------------+
//|                                                      SDL_MAM.mq4 |
//|                           Copyright © 2010, Andy Tjatur Pramono. |
//|                                            andy.tjatur@gmail.com |
//+------------------------------------------------------------------+
#property  copyright "Copyright © 2010, Andy Tjatur Pramono."
#property  link      "andy.tjatur@gmail.com"

#property indicator_separate_window
#property indicator_level1 0
#property indicator_levelcolor Yellow 
#property indicator_buffers 2 
#property indicator_color1 Blue
#property indicator_color2 Red
#property indicator_width1 3
#property indicator_width2 3

//---- input parameters 

extern int       period=20; 
extern int       method=3;                        
extern int       price=0;   
                        
//---- buffers 
double Uptrend[];
double Dntrend[];
double ExtMapBuffer[]; 


//+------------------------------------------------------------------+ 
//| Custom indicator initialization function                         | 
//+------------------------------------------------------------------+ 
int init() 
{ 
    IndicatorBuffers(3);  
    SetIndexBuffer(0, Uptrend); 
    //ArraySetAsSeries(Uptrend, true); 
    SetIndexBuffer(1, Dntrend); 
    //ArraySetAsSeries(Dntrend, true); 
    SetIndexBuffer(2, ExtMapBuffer); 
    ArraySetAsSeries(ExtMapBuffer, true); 
    
    SetIndexStyle(0,DRAW_LINE,STYLE_SOLID,3);
    SetIndexStyle(1,DRAW_LINE,STYLE_SOLID,3);
    
    IndicatorShortName("SDL_MAM by Andy Tjatur"); 
    
    return(0); 
} 

//+------------------------------------------------------------------+ 
//| Custor indicator deinitialization function                       | 
//+------------------------------------------------------------------+ 
int deinit() 
{ 
     
    return(0); 
} 

 
double WMA(int x, int p) 
{ 
    return(iMA(NULL, 0, p, 0, method, PRICE_CLOSE, x)-iMA(NULL,0,p,0,method,PRICE_OPEN,x));    
} 

//+------------------------------------------------------------------+ 
//| Custom indicator iteration function                              | 
//+------------------------------------------------------------------+ 
int start() 
{ 
    int counted_bars = IndicatorCounted(); 
    
    if(counted_bars < 0) 
        return(-1); 
                  
    int x = 0; 
    int p = MathSqrt(period);              
    int e = Bars - counted_bars + period + 1; 
    
    double vect[], trend[]; 
    
    if(e > Bars) 
        e = Bars;    

    ArrayResize(vect, e); 
    ArraySetAsSeries(vect, true);
    ArrayResize(trend, e); 
    ArraySetAsSeries(trend, true); 
    
    for(x = 0; x < e; x++) 
    { 
        vect[x] = 2*WMA(x, period/2) - WMA(x, period);        
 
    } 

    for(x = 0; x < e-period; x++)
     
        ExtMapBuffer[x] = iMAOnArray(vect, 0, p, 0, method, x);        
    
    for(x = e-period; x >= 0; x--)
    {     
        trend[x] = trend[x+1];
        if (ExtMapBuffer[x]> ExtMapBuffer[x+1]) trend[x] =1;
        if (ExtMapBuffer[x]< ExtMapBuffer[x+1]) trend[x] =-1;
    
    if (trend[x]>0)
    { Uptrend[x] = ExtMapBuffer[x]; 
      if (trend[x+1]<0) Uptrend[x+1]=ExtMapBuffer[x+1];
      Dntrend[x] = EMPTY_VALUE;
    }
    else              
    if (trend[x]<0)
    { 
      Dntrend[x] = ExtMapBuffer[x]; 
      if (trend[x+1]>0) Dntrend[x+1]=ExtMapBuffer[x+1];
      Uptrend[x] = EMPTY_VALUE;
    }              
    
  
    }
    
    return(0); 
} 
//+------------------------------------------------------------------+