array out of range in 'ZigZag.mq4' (77,28)

 

Hello,

I get the error during backtesting:

2014.12.17 21:44:13.420    2013.12.02 02:00  array out of range in 'ZigZag.mq4' (77,28)

I use:

 ZZ = iCustom(Symbol(),Period(),"ZigZag",ExtDepth,ExtDeviation,ExtBackstep,0,1);

The test runs from 1.1.2013 until 1.12.2014 and stops without any trades. If I start the test after 2.12.2013 I don´t get that errort. What do I have to change to avoid that error?

Thanks in advance!

 
May be it is the error of ZigZag.q4 and the 77th line?
 
gooly:
May be it is the error of ZigZag.q4 and the 77th line?
Hm, I don´t know what kind of error there should be. But I did not had trouble about array out of range at all till now so I probably need help to figure it out.
 
 ZZ = iCustom(Symbol(),Period(),"ZigZag",ExtDepth,ExtDeviation,ExtBackstep,0,1);
is this line 77 from ZigZag.mq4 ?
 
GumRai:
is this line 77 from ZigZag.mq4 ?

That is the line I call ZigZag with.

I am using the MetaQuotes ZigZag. But it seems that the history for the backtest is simply missing. I fix that and hope the array issue will be solved as well. Thanks for your answers!

//+------------------------------------------------------------------+
//|                                                       ZigZag.mq4 |
//|                   Copyright 2006-2014, MetaQuotes Software Corp. |
//|                                              https://www.mql4.com |
//+------------------------------------------------------------------+
#property copyright "2006-2014, MetaQuotes Software Corp."
#property link      "https://www.mql4.com"
#property strict

#property indicator_chart_window
#property indicator_buffers 1
#property indicator_color1  Red
//---- indicator parameters
input int InpDepth=12;     // Depth
input int InpDeviation=5;  // Deviation
input int InpBackstep=3;   // Backstep
//---- indicator buffers
double ExtZigzagBuffer[];
double ExtHighBuffer[];
double ExtLowBuffer[];
//--- globals
int    ExtLevel=3; // recounting's depth of extremums
//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int OnInit()
  {
   if(InpBackstep>=InpDepth)
     {
      Print("Backstep cannot be greater or equal to Depth");
      return(INIT_FAILED);
     }
//--- 2 additional buffers
   IndicatorBuffers(3);
//---- drawing settings
   SetIndexStyle(0,DRAW_SECTION);
//---- indicator buffers
   SetIndexBuffer(0,ExtZigzagBuffer);
   SetIndexBuffer(1,ExtHighBuffer);
   SetIndexBuffer(2,ExtLowBuffer);
   SetIndexEmptyValue(0,0.0);
//---- indicator short name
   IndicatorShortName("ZigZag("+string(InpDepth)+","+string(InpDeviation)+","+string(InpBackstep)+")");
//---- initialization done
   return(INIT_SUCCEEDED);
  }
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
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[])
  {
   int    i,limit,counterZ,whatlookfor=0;
   int    back,pos,lasthighpos=0,lastlowpos=0;
   double extremum;
   double curlow=0.0,curhigh=0.0,lasthigh=0.0,lastlow=0.0;
//--- check for history and inputs
   if(rates_total<InpDepth || InpBackstep>=InpDepth)
      return(0);
//--- first calculations
   if(prev_calculated==0)
      limit=InitializeAll();
   else 
     {
      //--- find first extremum in the depth ExtLevel or 100 last bars
      i=counterZ=0;
      while(counterZ<ExtLevel && i<100)
        {
         if(ExtZigzagBuffer[i]!=0.0)
            counterZ++;
         i++;
        }
      //--- no extremum found - recounting all from begin
      if(counterZ==0)
         limit=InitializeAll();
      else
        {
         //--- set start position to found extremum position
         limit=i-1;
         //--- what kind of extremum?
         if(ExtLowBuffer[i]!=0.0) 
           {
            //--- low extremum
            curlow=ExtLowBuffer[i];
            //--- will look for the next high extremum
            whatlookfor=1;
           }
         else
           {
            //--- high extremum
            curhigh=ExtHighBuffer[i];
            //--- will look for the next low extremum
            whatlookfor=-1;
           }
         //--- clear the rest data
         for(i=limit-1; i>=0; i--)  
           {
            ExtZigzagBuffer[i]=0.0;  
            ExtLowBuffer[i]=0.0;
            ExtHighBuffer[i]=0.0;
           }
        }
     }
//--- main loop      
   for(i=limit; i>=0; i--)
     {
      //--- find lowest low in depth of bars
      extremum=low[iLowest(NULL,0,MODE_LOW,InpDepth,i)];
      //--- this lowest has been found previously
      if(extremum==lastlow)
         extremum=0.0;
      else 
        { 
         //--- new last low
         lastlow=extremum; 
         //--- discard extremum if current low is too high
         if(low[i]-extremum>InpDeviation*Point)
            extremum=0.0;
         else
           {
            //--- clear previous extremums in backstep bars
            for(back=1; back<=InpBackstep; back++)
              {
               pos=i+back;
               if(ExtLowBuffer[pos]!=0 && ExtLowBuffer[pos]>extremum)
                  ExtLowBuffer[pos]=0.0; 
              }
           }
        } 
      //--- found extremum is current low
      if(low[i]==extremum)
         ExtLowBuffer[i]=extremum;
      else
         ExtLowBuffer[i]=0.0;
      //--- find highest high in depth of bars
      extremum=high[iHighest(NULL,0,MODE_HIGH,InpDepth,i)];
      //--- this highest has been found previously
      if(extremum==lasthigh)
         extremum=0.0;
      else 
        {
         //--- new last high
         lasthigh=extremum;
         //--- discard extremum if current high is too low
         if(extremum-high[i]>InpDeviation*Point)
            extremum=0.0;
         else
           {
            //--- clear previous extremums in backstep bars
            for(back=1; back<=InpBackstep; back++)
              {
               pos=i+back;
               if(ExtHighBuffer[pos]!=0 && ExtHighBuffer[pos]<extremum)
                  ExtHighBuffer[pos]=0.0; 
              } 
           }
        }
      //--- found extremum is current high
      if(high[i]==extremum)
         ExtHighBuffer[i]=extremum;
      else
         ExtHighBuffer[i]=0.0;
     }
//--- final cutting 
   if(whatlookfor==0)
     {
      lastlow=0.0;
      lasthigh=0.0;  
     }
   else
     {
      lastlow=curlow;
      lasthigh=curhigh;
     }
   for(i=limit; i>=0; i--)
     {
      switch(whatlookfor)
        {
         case 0: // look for peak or lawn 
            if(lastlow==0.0 && lasthigh==0.0)
              {
               if(ExtHighBuffer[i]!=0.0)
                 {
                  lasthigh=High[i];
                  lasthighpos=i;
                  whatlookfor=-1;
                  ExtZigzagBuffer[i]=lasthigh;
                 }
               if(ExtLowBuffer[i]!=0.0)
                 {
                  lastlow=Low[i];
                  lastlowpos=i;
                  whatlookfor=1;
                  ExtZigzagBuffer[i]=lastlow;
                 }
              }
             break;  
         case 1: // look for peak
            if(ExtLowBuffer[i]!=0.0 && ExtLowBuffer[i]<lastlow && ExtHighBuffer[i]==0.0)
              {
               ExtZigzagBuffer[lastlowpos]=0.0;
               lastlowpos=i;
               lastlow=ExtLowBuffer[i];
               ExtZigzagBuffer[i]=lastlow;
              }
            if(ExtHighBuffer[i]!=0.0 && ExtLowBuffer[i]==0.0)
              {
               lasthigh=ExtHighBuffer[i];
               lasthighpos=i;
               ExtZigzagBuffer[i]=lasthigh;
               whatlookfor=-1;
              }   
            break;               
         case -1: // look for lawn
            if(ExtHighBuffer[i]!=0.0 && ExtHighBuffer[i]>lasthigh && ExtLowBuffer[i]==0.0)
              {
               ExtZigzagBuffer[lasthighpos]=0.0;
               lasthighpos=i;
               lasthigh=ExtHighBuffer[i];
               ExtZigzagBuffer[i]=lasthigh;
              }
            if(ExtLowBuffer[i]!=0.0 && ExtHighBuffer[i]==0.0)
              {
               lastlow=ExtLowBuffer[i];
               lastlowpos=i;
               ExtZigzagBuffer[i]=lastlow;
               whatlookfor=1;
              }   
            break;               
        }
     }
//--- done
   return(rates_total);
  }
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
int InitializeAll()
  {
   ArrayInitialize(ExtZigzagBuffer,0.0);
   ArrayInitialize(ExtHighBuffer,0.0);
   ArrayInitialize(ExtLowBuffer,0.0);
//--- first counting position
   return(Bars-InpDepth);
  }
//+------------------------------------------------------------------+
 

is this line 77?

         if(ExtZigzagBuffer[i]!=0.0)

I would place this right before this line:

         Comment("i: ",i,"  rates_total: ",rates_total,"  ArrSz: ",ArraySize(ExtZigzagBuffer)); // in case time[i] failes
         Comment("i: ",i,"  rates_total: ",rates_total,"  ArrSz: ",ArraySize(ExtZigzagBuffer),
                 "  t[",i,"]: ",TimeToStr(time[i]),"  t[",(rates_total-1),"]: ",TimeToStr(time[rates_total-1]) );

and start the tester in visual mode and attach this modified indi. to the tester-chart.

If the array access fails you should be able to read the failing values of the vars at the screen without having hundreds of loglines to go through.

If this doesn't work you have to use the old way: just replace Comment(..  by Print(..

 
gooly:

is this line 77?

I would place this right before this line:

and start the tester in visual mode and attach this modified indi. to the tester-chart.

If the array access fails you should be able to read the failing values of the vars at the screen without having hundreds of loglines to go through.

If this doesn't work you have to use the old way: just replace Comment(..  by Print(..

Thanks for your effort! I put your comments into the code and got:

I figured out how to avoid the problem. It downloaded history from 1.1.2013 until 1.12.2014. When I start the test from 1.1.2013 ZigZag has not enough history to calculate the first zig zags. When I start from 1.2.2013 it works :)