Invalid array access

Arrays are always passed by reference. You have to add "&" for the first array also:

int IdentifyTradesToIgnore(double& DataArray[],int& IgnoreArray[])

 For explanation and examples see documentation: Passing Parameters 

thanks for that info.

unfortunately it doesn't seem to fix the issue though. I still get the same error message. 

I downloaded your code, but it can't be compiled because there are additional files included.

Add "&" infront of arrays in all your function definitions. 

Below you try to return an array as function result. It can't be done, and besides that type of function result is int, so you can return only one element of the array: return(IgnoreArray[some_idx]);

int IdentifyTradesToIgnore(double DataArray[],int& IgnoreArray[])
   {
   int      recentindex,i,candidateindex;
   double   MathAvgOnArray,MathStdDevOnArray;
   
   
   // DataArray - identify outliers beyond +/- 8.5 sigma (99.9% CI based on generalized distribution)
   if(ArrayRange(DataArray,0)<3) 
   return(IgnoreArray); // if there are few members of the data array then return without calculation
   
   MathAvgOnArray=MathAvg(DataArray);
   MathStdDevOnArray=MathStdev(DataArray);
   recentindex=0; // reset index position for IgnoreArray searches
   for(i=0;i<ArrayRange(DataArray,0);i++)
      {
      if(DataArray[i]<(MathAvgOnArray-8.5*MathStdDevOnArray) || DataArray[i]>(MathAvgOnArray+8.5*MathStdDevOnArray))
         {
         // check to see if whether or not trade order "i" was previously identified and logged as an excursion trade
         candidateindex=ArrayBsearch(IgnoreArray,i,WHOLE_ARRAY,recentindex,MODE_ASCEND);
         if(IgnoreArray[candidateindex]==i+1)
            {
            recentindex=candidateindex;
            continue; // return to the next outermost loop because we already know the existing i is a documented excursion trade
            }
         if(IgnoreArray[ArrayRange(IgnoreArray,0)-1]==-1)
            {
            IgnoreArray[0]=i+1;
            recentindex=MathMax(recentindex-1,0);  // back-up the recentindex by 1
            continue;
            }
         ArrayResize(IgnoreArray,ArrayRange(IgnoreArray,0)+1);
         IgnoreArray[ArrayRange(IgnoreArray,0)-1]=i+1;
         ArraySort(IgnoreArray,WHOLE_ARRAY,0,MODE_ASCEND);   // sort the array so the most recently appended trade order number is properly indexed
         recentindex=MathMax(recentindex-1,0);  // back-up the recentindex by 1
         }
      }
   return(IgnoreArray);
   }

There is a lots of code. If you don't have experience with MQL4, your best bet would be to hire someone to do it in freelance section

I am new to Forex trading and I know next to nothing about MQL4 coding but I would like to get this code working.
I will appreciate your help.

The errors from the MQL4 program are:

1. 'close' - invalid array access

2. 'ticket' - variable already defined.

I have made the lines the errors refer to bold and red for easy identification

Below is the code.

// Expert Advisor start function

void OnTick()

{

    double ema21 = iMA(NULL, 0, 21, 0, MODE_EMA, PRICE_CLOSE, 0);

    double sma50 = iMA(NULL, 0, 50, 0, MODE_SMA, PRICE_CLOSE, 0);

    double stopLossPrice = iMA(NULL, 0, 21, 0, MODE_SMA, PRICE_CLOSE, 0);

    if (ema21 > sma50 && Close > ema21 && OrdersTotal() == 0) {

        int ticket = OrderSend(Symbol(), OP_BUY, LotSize, Ask, 0, Ask - stopLossPrice, Ask + (2 * (Ask - stopLossPrice)), "Buy Order", 0, 0, Green);

        if (ticket > 0) {

            Print("Buy order opened successfully");

        } else {

            Print("Error opening buy order: ", GetLastError());

        }

    } else if (ema21 < sma50 && Close < ema21 && OrdersTotal() == 0) {

        int ticket = OrderSend(Symbol(), OP_SELL, LotSize, Bid, 0, Bid + stopLossPrice, Bid - (2 * stopLossPrice), "Sell Order", 0, 0, Red);

        if (ticket > 0) {

            Print("Sell order opened successfully");

        } else {

            Print("Error opening sell order: ", GetLastError());

        }

1. Don't Hijack other threads for your off-topic post. Next time, make your own, new, thread.

2. Don't double post! You already had another thread open.

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