Correct Way to Loop Through Last [X] Number of Variable Indexes

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Cnotey 2016.03.25 19:41
 

Hi there,

New to the MQL4 language and C++ in general.  I am a C# coder by nature, so as you can imagine MQL4 is being a bit difficult.  My normal MQL4 coder is out of town for a week, so I need a bit of help with something.

I am trying to loop through the last [X] number of indexes for a defined variable.  I need to access the last 14 values of a variable in the code below.

I am not expecting someone to write the code for me.  Just point me in the correct direction.

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 limit=rates_total-prev_calculated;
//---
//ArraySetAsSeries(candle,false);
//ArraySetAsSeries(shadow,false);
//---
   if(prev_calculated>0)
      limit++;
 
   for(int i=0; i<limit; i++)
     {

      ShadowsBuffer[i] = (shadow_height(open[i], high[i], low[i], close[i])/Candle_SMA);//<-----------This should return the SUM of the last [X] values of shadow_height and divide by the input variable Candle_SMA
      CandlesBuffer[i] = (candle_height(open[i], high[i], low[i], close[i])/Candle_SMA);//<-----------This should return the SUM of the last [X] values of candle_height and divide by the input variable Candle_SMA
     }
//--- return value of prev_calculated for next call
   return(rates_total);
  }

double candle_height[](double open, double high, double low, double close)
{
      double CH = MathAbs(open - close);
      double TOC = MathMax(open, close);
      double BOC = MathMin(open, close);
      double TS = high - TOC;
      double BS = BOC - low;
      double AH = TS + BS + CH;
      double TSraw = 100 * (TS/AH);
      double BSraw = 100 * (BS/AH);
      double CHraw = 100 * (CH/AH);
      double shadow_height_raw = TSraw - BSraw;
      double candle_height_raw[] = CHraw - shadow_height_raw;  //<------------ Don't know if this is the correct use of the array?
      for(int p=0; p<Candle_SMA; p++)
      {
         candle += candle_height_raw[p];  //<------------The issue is here.  I am trying to pull the last 14 values of candle_height_raw and add them together, return the value, and provide an SMA in the code above.
      }
      return(candle);
}

Also, if anyone knows a better way to do what I am trying to do, I'm open for suggestion!

Thanks,

Cnotey

 

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13009
WHRoeder 2016.03.25 20:14 #
 
Cnotey I need to access the last 14 values of a variable in the code below.
double candle_height[](double open, double high, double low, double close)
  1. ShadowsBuffer[i] = (shadow_height(open[i], high[i], low[i], close[i])/C
    The variables passed to OnCalculate, are not guaranteed to be in series order (newest = 0.) The Predefined Variables - MQL4 Reference (e.g. Close[]) are.
  2. double candle_height[](double open, double high, double low, double close)
    Bogus. You need to access n values, but you pass single values, so it can't possibly work. Just use the predefined's and you only have to pass the starting index.
  3. double candle_height_raw[] = CHraw - shadow_height_raw; 
    You have a empty array, it can't be assigned to. Your function has no loop to fill the array, so can't work.
  4. I don't use any of the arguments. Use the predefined's
       int limit=rates_total-prev_calculated;
       if(prev_calculated>0) limit++;
       for(int i=0; i<limit; i++)
    You have a look back of 14 ("last 14 values") you must handle the it to avoid error 4002.
    int counted = IndicatorCounted();
    for(int i=Bars -1 -MathMax(14, counted); i >= 0; --i){
       :

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2
Cnotey 2016.03.25 20:53 #
 
WHRoeder:
  1. The variables passed to OnCalculate, are not guaranteed to be in series order (newest = 0.) The Predefined Variables - MQL4 Reference (e.g. Close[]) are.
  2. Bogus. You need to access n values, but you pass single values, so it can't possibly work. Just use the predefined's and you only have to pass the starting index.
  3. You have a empty array, it can't be assigned to. Your function has no loop to fill the array, so can't work.
  4. I don't use any of the arguments. Use the predefined's
    You have a look back of 14 ("last 14 values") you must handle the it to avoid error 4002.

Thank you for your help.  Do I still need to loop through to fill the predefined variables (e.g. Close[]) to fill the values?  Or do I just give it Close[i..14]?
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13009
WHRoeder 2016.03.25 21:16 #
 
Entry #5 didn't get saved. I don't know what you are trying to compute; I can't follow your code. Try something like:
double average_body_percent(int shift, int len=14){
   double sum=0;
   for(int i=shift + len - 1; i >= shift; --i){
      double body = MathAbs(Open[i] - Close[i]);
      sum += body / (High[i] - Low[i]);
   }
   return sum / len * 100;
}

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