fractal not work correctly

[faustf]

Hi guys, I have an issue with an indicator, specifically on JForex. I have an indicator called Fractal. Setting the Fractal to 1, the indicator creates an arrow (when the conditions are met) immediately as the new candle opens. However, with this script I'm trying to modify for MT4, the arrow doesn't appear until at least after 3 candles, that is, on candle 2. Why is that? Can anyone help me out?

//+------------------------------------------------------------------+
//|                                                     Fractals.mq4 |
//|                      Copyright © 2005, MetaQuotes Software Corp. |
//|                                        http://www.metaquotes.net |
//+------------------------------------------------------------------+
#property copyright "Copyright © 2005, MetaQuotes Software Corp."
#property link      "http://www.metaquotes.net"

#property indicator_chart_window
#property indicator_buffers 2
#property indicator_color1 Red
#property indicator_color2 Blue
//---- parametri di input
extern int candlesBefore = 1;  // Quante candele prima considerare
extern string CandlesBeforeOHLC = "C";  // Il trigger può essere O.H.L.C

//---- buffer
double ExtUpFractalsBuffer[];
double ExtDownFractalsBuffer[];
//+------------------------------------------------------------------+
//| Funzione di inizializzazione dell'indicatore personalizzato      |
//+------------------------------------------------------------------+
int init()
  {
//---- mappatura dei buffer dell'indicatore
    SetIndexBuffer(0, ExtUpFractalsBuffer);
    SetIndexBuffer(1, ExtDownFractalsBuffer);   
//---- impostazioni di disegno
    SetIndexStyle(0, DRAW_ARROW);
    SetIndexArrow(0, 119);
    SetIndexStyle(1, DRAW_ARROW);
    SetIndexArrow(1, 119);
//----
    SetIndexEmptyValue(0, 0.0);
    SetIndexEmptyValue(1, 0.0);
//---- nome per DataWindow
    SetIndexLabel(0, "Frattale Rialzista");
    SetIndexLabel(1, "Frattale Ribassista");
//---- inizializzazione completata   
   return(0);
  }
//+------------------------------------------------------------------+
//| Funzione di deinizializzazione dell'indicatore personalizzato     |
//+------------------------------------------------------------------+
int deinit()
  {
   return(0);
  }
//+------------------------------------------------------------------+
//| Funzione di iterazione dell'indicatore personalizzato            |
//+------------------------------------------------------------------+
int start()
  {
   int i, nCountedBars;
   double dCurrent;
   bool bFound;
   nCountedBars = IndicatorCounted();
//---- verrà ricontata l'ultima barra contata    
   if(nCountedBars <= 2)
      i = Bars - nCountedBars - 3;
   if(nCountedBars > 2)
     {
      nCountedBars--;
      i = Bars - nCountedBars - 1;
     }
//---- Frattali Rialzisti e Ribassisti
   while(i >= 2)
     {
      //---- Frattali Rialzisti
      bFound = false;
      dCurrent = High[i];
      
      if (candlesBefore == 1) {
         if(dCurrent > High[i+1] && dCurrent > High[i-1])
           {
            bFound = true;
            ExtUpFractalsBuffer[i] = dCurrent;
           }
      } 
      else if (candlesBefore == 2) {
         if(dCurrent > High[i+1] && dCurrent > High[i+2] && dCurrent > High[i-1] && dCurrent > High[i-2])
           {
            bFound = true;
            ExtUpFractalsBuffer[i] = dCurrent;
           }
      }    
        
      //---- Frattali Ribassisti
      dCurrent = Low[i];
      if(dCurrent < Low[i+1] && dCurrent < Low[i-1])
        {
         bFound = true;
         ExtDownFractalsBuffer[i] = dCurrent;
        }
                   i--;
  }
//----
   return(0);
  }
//+------------------------------------------------------------------+

[Marzena Maria Szmit]

Hi

This is result of a logic – how fractals are calculated here. As you can see n the code the fractal is detected when we have a local maximum/minimum but to find local extremes, you need to have candles from both sides of the current candle (to check for example if current low price s lower than previous candle and is lower from next candle. And this can be checked only if we have those candles available and closed. In this code there is some extra “confirmation” that this local extreme is the highest/lowest price from two nearby candles – that’s why it requires two candles after to confirm this local extreme price. And hence the signal is after 2nd closed candle (not earlier). I’m not sure how the fractals are calculated on JForex – but they might use some “predictions” or assumptions which can be later “repainted” or recalculated. Here it won’t repaint at all. 

Best Regards

[Nardus Van Staden]

faustf:
Hi guys, I have an issue with an indicator, specifically on JForex. I have an indicator called Fractal. Setting the Fractal to 1, the indicator creates an arrow (when the conditions are met) immediately as the new candle opens. However, with this script I'm trying to modify for MT4, the arrow doesn't appear until at least after 3 candles, that is, on candle 2. Why is that? Can anyone help me out?

So it checks for fractals based on the current candle and the specified number of candles before it ( candlesBefore ).
If candlesBefore is set to 1, it compares the current high/low with the high/low of the candle preceding it ( i+1 and i-1 ).
If candlesBefore is set to 2, it additionally compares the current high/low with the high/low of the second candle before and after it ( i+2 and i-2 ).

The issue arises from the way the loop is structured and how fractals are identified. Let's consider the case here when candlesBefore is set to 1:

On the first loop iteration, it compares the current candle's high/low with the previous candle's high/low. If the conditions for a fractal are met, it marks the current candle as a fractal.
On the second loop iteration ( i-- ), it compares the second candle's high/low with the previous candle's high/low. However, at this point, the previous candle is the one before the one marked as a fractal in the first iteration. Therefore, the indicator waits until the third candle to identify and mark the fractal.

To fix this issue, you can adjust the loop to start from the most recent candle ( i = Bars - 1 ) and iterate backwards. Then, you can compare the current candle with the specified number of candles before it, irrespective of whether a fractal is already identified in previous iterations.

Adjust the loop in the start() function like this, delete everything from the int start and paste this, then compile and test

int start()
{
    int i, nCountedBars;
    double dCurrent;
    bool bFound;
    nCountedBars = IndicatorCounted();

    // Start from the most recent candle
    i = Bars - 1;

    //Then Iterate backwards
    while (i >= 2)
    {
        // Fractals identification logic
        //---- Fractals Bullish
        bFound = false;
        dCurrent = High[i];
        
        if (candlesBefore == 1) {
            if(dCurrent > High[i+1] && dCurrent > High[i-1])
            {
                bFound = true;
                ExtUpFractalsBuffer[i] = dCurrent;
            }
        } 
        else if (candlesBefore == 2) {
            if(dCurrent > High[i+1] && dCurrent > High[i+2] && dCurrent > High[i-1] && dCurrent > High[i-2])
            {
                bFound = true;
                ExtUpFractalsBuffer[i] = dCurrent;
            }
        }    

        //---- Fractals Bearish
        dCurrent = Low[i];
        if(dCurrent < Low[i+1] && dCurrent < Low[i-1])
        {
            bFound = true;
            ExtDownFractalsBuffer[i] = dCurrent;
        }

        // Decrement counter
        i--;
    }

    return (0);
}