Is there an error in the Heikin-Ashi indicator ?

[Avery Horton]

 The Heikin-Ashi technique uses a modified formula:

• xClose = (Open+High+Low+Close)/4
  o Average price of the current bar
• xOpen = [xOpen(Previous Bar) + Close(Previous Bar)]/2
  o Midpoint of the previous bar
• xHigh = Max(High, xOpen, xClose)
  o Highest value in the set
• xLow = Min(Low, xOpen, xClose)
  o Lowest value in the set

Shouldn't the highlighted line have i+1 for the HA calculation

 //--- preliminary calculation

   if(prev_calculated>1)

      pos=prev_calculated-1;

   else

     {

      //--- set first candle

      if(open[0]<close[0])

        {

         ExtLowHighBuffer[0]=low[0];

         ExtHighLowBuffer[0]=high[0];

        }

      else

        {

         ExtLowHighBuffer[0]=high[0];

         ExtHighLowBuffer[0]=low[0];

        }

      ExtOpenBuffer[0]=open[0];

      ExtCloseBuffer[0]=close[0];

      //---

      pos=1;

     }

//--- main loop of calculations

   for(i=pos; i<rates_total; i++)

     {

      haOpen=(ExtOpenBuffer[i-1]+ExtCloseBuffer[i-1])/2;

      haClose=(open[i]+high[i]+low[i]+close[i])/4;

      haHigh=MathMax(high[i],MathMax(haOpen,haClose));

      haLow=MathMin(low[i],MathMin(haOpen,haClose));

      if(haOpen<haClose)

        {

         ExtLowHighBuffer[i]=haLow;

         ExtHighLowBuffer[i]=haHigh;

        }

      else

        {

         ExtLowHighBuffer[i]=haHigh;

         ExtHighLowBuffer[i]=haLow;

        }

      ExtOpenBuffer[i]=haOpen;

      ExtCloseBuffer[i]=haClose;

     }

//--- done

   return(rates_total);

  }

//+------------------------------------------------------------------+

[honest_knave]

Take a look at the bit of code preceding the snippet you posted. 

   ArraySetAsSeries(ExtLowHighBuffer,false);
   ArraySetAsSeries(ExtHighLowBuffer,false);
   ArraySetAsSeries(ExtOpenBuffer,false);
   ArraySetAsSeries(ExtCloseBuffer,false);
   ArraySetAsSeries(open,false);
   ArraySetAsSeries(high,false);
   ArraySetAsSeries(low,false);
   ArraySetAsSeries(close,false);