Move code from Custom indicator does not success

[Golf]

I have the following custom indicators "Aroon_Up_Down.mq4"

//+------------------------------------------------------------------+
//|                                         Custom Aroon Up & Dn.mq4 |
//|                                                        rafcamara |
//|                 Upgraded by Andriy Moraru from www.earnforex.com |
//+------------------------------------------------------------------+
#property  copyright "rafcamara"
#property  link      "[e-mail]"
//---- indicator settings
#property  indicator_separate_window
#property  indicator_buffers 2
#property  indicator_color1  DodgerBlue
#property  indicator_color2  Red

//---- indicator parameters
extern int AroonPeriod = 14;
extern bool MailAlert = false;  //Alerts will be mailed to address set in MT4 options
extern bool SoundAlert = false; //Alerts will sound on indicator cross

//---- indicator buffers
double     AroonUpBuffer[];
double     AroonDnBuffer[];

int LastBars = 0;

//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int init()
  {
   //---- 2 additional buffers are used for counting.
   IndicatorBuffers(4);
   SetIndexBuffer(0, AroonUpBuffer);
   SetIndexBuffer(1, AroonDnBuffer);

   //---- drawing settings
   SetIndexStyle(0,DRAW_LINE,STYLE_SOLID,1);
   SetIndexStyle(1,DRAW_LINE,STYLE_SOLID,1);
  SetIndexDrawBegin(0,200);
  SetIndexDrawBegin(1,200);
   IndicatorDigits(1);
   
   //---- name for DataWindow and indicator subwindow label
   IndicatorShortName("Aroon Up & Dn("+AroonPeriod+")");
   //---- initialization done
   return(0);
  }
//+------------------------------------------------------------------+
//| Aroon Up & Dn                                                    |
//+------------------------------------------------------------------+
int start()  
  {
   double   AroonUp,AroonDn;
   int      ArPer,limit,i;     
   int      UpBarDif,DnBarDif;
   int      counted_bars=IndicatorCounted(); 
   ArPer=AroonPeriod;                  //Short name
   
   //---- check for possible errors
   if(counted_bars<0) return(-1);
   if(AroonPeriod<1) return(-1);      
   //---- initial zero
   if(counted_bars<1)
     {
      for(i=1;i<=ArPer;i++) AroonUpBuffer[Bars-i]=0.0;
      for(i=1;i<=ArPer;i++) AroonDnBuffer[Bars-i]=0.0;
     } 

   //---- last counted bar will be recounted
   if(counted_bars>0) counted_bars--;
   limit=Bars-counted_bars;

   //----Calculation---------------------------
   for( i=0; i<limit; i++)
   {
           int HH = Highest(NULL,0,MODE_HIGH,ArPer,i);   //Periods from HH         
           int LL = Lowest(NULL,0,MODE_LOW,ArPer,i);              //Periods from LL

      UpBarDif = i-HH;                         //Period substraction
      DnBarDif = i-LL;                            //Period substraction
      
      AroonUpBuffer[i]=100+(100/ArPer)*(UpBarDif);            //Adjusted Aroon Up
      AroonDnBuffer[i]=100+(100/ArPer)*(DnBarDif);            //Adjusted Aroon Down

      if (LastBars != Bars)
      {
         if ((AroonUpBuffer[0] > AroonDnBuffer[0]) && (AroonUpBuffer[1] <= AroonDnBuffer[1]))
         {
            if (MailAlert) SendMail("Aroon Up & Down Indicator Alert", "The indicator produced a cross (Blue ABOVE Red) on " + Year() + "-" + Month() + "-" + Day() + " " + Hour() + ":" + Minute());
            if (SoundAlert) Alert("Aroon Up & Down produced a cross (Blue ABOVE Red)");
         }
         else if ((AroonUpBuffer[0] < AroonDnBuffer[0]) && (AroonUpBuffer[1] >= AroonDnBuffer[1]))
         {
            if (MailAlert) SendMail("Aroon Up & Down Indicator Alert", "The indicator produced a cross (Blue BELOW Red) on " + Year() + "-" + Month() + "-" + Day() + " " + Hour() + ":" + Minute());
            if (SoundAlert) Alert("Aroon Up & Down produced a cross (Blue BELOW Red)");
         }
         LastBars = Bars;
      }
   }
   return(0);
  }

In the EA it is being used like this (iCustom(NULL,0, "Aroon_Up_Down", 38, false, false, 1, 2)

      // LONG: (Aroon_Down(38) Crosses Above Stoch(14, 3, 3))
      if(TradeLong) {
         bool LongEntryCondition = ((iCustom(NULL,0, "Aroon_Up_Down", 38, false, false, 1, 2) < iStochastic(NULL, 0, 14, 3, 3, MODE_SMA, 0, MODE_MAIN, 2)) && (iCustom(NULL,0, "Aroon_Up_Down", 38, false, false, 1, 1) > iStochastic(NULL, 0, 14, 3, 3, MODE_SMA, 0, MODE_MAIN, 1)));
         if(LongEntryCondition == true) {
            openPosition(1);
         }
      }
   
      // SHORT: (Aroon_Down(38) Crosses Below Stoch(14, 3, 3))
      if(TradeShort) {
         bool ShortEntryCondition = ((iCustom(NULL,0, "Aroon_Up_Down", 38, false, false, 1, 2) > iStochastic(NULL, 0, 14, 3, 3, MODE_SMA, 0, MODE_MAIN, 2)) && (iCustom(NULL,0, "Aroon_Up_Down", 38, false, false, 1, 1) < iStochastic(NULL, 0, 14, 3, 3, MODE_SMA, 0, MODE_MAIN, 1)));
         if(ShortEntryCondition == true) {
            openPosition(-1);
         }
      }

What i want to do is that I want to merge "Aroon_Up_Down.mq4" Into EA.

What i understand is that iCustom will call Aroon_Up_Down.mq4 and the following highlighted code here

iCustom(NULL,0, "Aroon_Up_Down", 38, false, false, 1, 2)

I understand that It means that it will get the value from AroonDnBuffer

Since in the indicators the code is being set as

SetIndexBuffer(1, AroonDnBuffer);

And number 2 is index array

I tried to make a simple replacement for a function call so instead of 

(iCustom(NULL,0, "Aroon_Up_Down", 38, false, false, 1, 2)

I Use

iAroonDown(38,2)

This is the function i have created, however after i run the backtest to check if this is working, it seems that the function i replaced does not work well, what is being wrong with this ?

double iAroonDown(int AroonPeriod, int index) {
   int LastBars = 0;
   double  AroonDnBuffer[];
   double   AroonDn;
   int      ArPer,limit,i;     
   int      UpBarDif,DnBarDif;
   int      counted_bars=IndicatorCounted(); 
   ArPer=AroonPeriod;                  //Short name
   
   //---- check for possible errors
   if(counted_bars<0) return(-1);
   if(AroonPeriod<1) return(-1);      
   //---- initial zero
   if(counted_bars<1)
     {
      for(i=1;i<=ArPer;i++) AroonDnBuffer[Bars-i]=0.0;
     } 

   //---- last counted bar will be recounted
   if(counted_bars>0) counted_bars--;
   limit=Bars-counted_bars;

   //----Calculation---------------------------
   for( i=0; i<limit; i++)
   {
          int LL = Lowest(NULL,0,MODE_LOW,ArPer,i);               //Periods from LL

      DnBarDif = i-LL;                            //Period substraction
      
      AroonDnBuffer[i]=100+(100/ArPer)*(DnBarDif);            //Adjusted Aroon Down

      if (LastBars != Bars)
      {
         LastBars = Bars;
      }
   }  
   return  AroonDnBuffer[index];
}