multidimensional array: Out of Range

[amine.mounir]

Dear,

I would like to contrast DIs (ADX) with different averaging time frame , so I created a custom Indicator using the basics of ADX Wilder Moving from PD and ND along with TR to PDS, NDS, PDI and NDI with different averaging number (1,2, 3, to 14). I would like generate a matrix of PDI with in row time and columns 14 PDIs with each different averaging number. I guess that this can be handled with array computation. I tried to do (code below) but i get the message out of range. Please, I appreciate your help and comments:

//--- input parameters
input int InpNberPeriod=14; // Period
int filePtr; 
//---- buffers
double    ExtTBuffer[];
double    ExtPDBuffer[];
double    ExtNDBuffer[];
double    ExtTRBuffer[];
double    PDI[][14];
double    NDI[][14];
double    PDS[][14];
double    NDS[][14];
double    ATR[][14];
//--- global variable
int       ExtNberPeriod;
//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
void OnInit()
  {
//--- check for input parameters
   if(InpNberPeriod>=100 || InpNberPeriod<=0)
     {
      ExtNberPeriod=14;
      printf("Incorrect value for input variable InpNberPeriod=%d. Indicator will use value=%d for calculations.",InpNberPeriod,ExtNberPeriod);
     }
   else ExtNberPeriod=InpNberPeriod;
   
//---- indicator buffers
  
   SetIndexBuffer(0,ExtPDBuffer,INDICATOR_CALCULATIONS);
   SetIndexBuffer(1,ExtNDBuffer,INDICATOR_CALCULATIONS);
   SetIndexBuffer(2,ExtTRBuffer,INDICATOR_CALCULATIONS);

//--- set draw begin
   PlotIndexSetInteger(0,PLOT_DRAW_BEGIN,ExtNberPeriod<<1);
   PlotIndexSetInteger(1,PLOT_DRAW_BEGIN,ExtNberPeriod+1);
   PlotIndexSetInteger(2,PLOT_DRAW_BEGIN,ExtNberPeriod+1);
//--- indicator short name
   string short_name="ADX("+string(ExtNberPeriod)+")";
   IndicatorSetString(INDICATOR_SHORTNAME,short_name);
//--- change 1-st index label
   PlotIndexSetString(0,PLOT_LABEL,short_name);
//--- indicator digits
   IndicatorSetInteger(INDICATOR_DIGITS,2);
//---- end of initialization function
filePtr =FileOpen("FileOutput.csv",FILE_WRITE|FILE_CSV);
  }
//+------------------------------------------------------------------+
//| Custom indicator iteration function                              |
//+------------------------------------------------------------------+
int OnCalculate(const int rates_total,
                const int prev_calculated,
                const datetime &time[],
                const double &open[],
                const double &high[],
                const double &low[],
                const double &close[],
                const long &tick_volume[],
                const long &volume[],
                const int &spread[])
  {
//--- checking for bars count
   if(rates_total<ExtNberPeriod)
      return(0);
//--- detect start position
   int start;
   if(prev_calculated>1) start=prev_calculated-1;
   else
     {
      start=1;
      for(int i=0;i<ExtNberPeriod;i++)
        {
         ExtTBuffer[i]=0;
         ExtPDBuffer[i]=0;
         ExtNDBuffer[i]=0;
         ExtTRBuffer[i]=0;
        }
     }
//--- main cycle
   for(int i=start;i<rates_total && !IsStopped();i++)
     {  //--- get some data
      double Hi    =high[i];
      double prevHi=high[i-1];
      double Lo    =low[i];
      double prevLo=low[i-1];
      double prevCl=close[i-1];
      //--- fill main positive and main negative buffers
      double dTmpP=Hi-prevHi;
      double dTmpN=prevLo-Lo;
      if(dTmpP<0.0) dTmpP=0.0;
      if(dTmpN<0.0) dTmpN=0.0;
      if(dTmpN==dTmpP)
        {
         dTmpN=0.0;
         dTmpP=0.0;
        }
      else
        {
         if(dTmpP<dTmpN) dTmpP=0.0;
         else            dTmpN=0.0;
        }
      ExtPDBuffer[i]=dTmpP;
      ExtNDBuffer[i]=dTmpN;
      double tr=MathMax(MathMax(MathAbs(Hi-Lo),MathAbs(Hi-prevCl)),MathAbs(Lo-prevCl));
      ExtTRBuffer[i]=tr;
      
      for(int j=0;j<14;j++){
      if(i<ExtNberPeriod)
        {
        
       
         ATR[i][j]=0.0;
         PDS[i][j]=0.0;
         NDS[i][j]=0.0;
        
        }
      else
        {
         ATR[i][j]=SimpleMA(i,j+1,ExtTRBuffer);
         PDS[i][j]=SimpleMA(i,j+1,ExtPDBuffer);
         NDS[i][j]=SimpleMA(i,j+1,ExtNDBuffer);
          }
          if(ATR[i][j]!=0.0)
        {
         PDI[i][j]=100.0*PDS[i][j]/ATR[i][j];
         NDI[i][j]=100.0*NDS[i][j]/ATR[i][j];
    
         }
      else
        {
         PDI[i][j]=0.0;
         NDI[i][j]=0.0;
        }
           
    FileWrite(filePtr ,TimeToString(TimeCurrent(), TIME_DATE | TIME_MINUTES ),PDI[i][j]);
        }
    
        
        
 

  
     }
//---- OnCalculate done. Return new prev_calculated.
   return(rates_total);
  }

[lawrence910426]

I have met similar problem as you did. Seems like accessing 2d array in `OnCalculate` would lead to `Index out of bound` error.

[Carl Schreiber]

1. use the debugger to check the index and the array size (of any dimension) before you access the array: https://www.mql5.com/en/articles/654
2. use ArrayRange() to check the sizes of the dimensions.
   

[Alexandre Borela]

You didn't set PDI, NDI, etc.. as buffers with SetIndexBuffer, just declaring a variable as x[] won't work because it is an empty array.