Errors, bugs, questions - page 735

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joo:

Found a "confusion".

Why doesn't the compiler like the define of the second b variable?

And in general, how do I handle this situation?

It doesn't like the define.

It just writes another error - wrong variable type for the array dimension

You can only specify constants in dimensions

[Andrey Dik]

sergeev:

it's not the define that he doesn't like.

It also writes another error - wrong variable type for the array dimension

Only constants may be specified in dimensions

Constants won't work either, there will be an error:

const int AA =11;
ArrWe m[AA];

Access specifiers

Access specifiers tell the compiler how to access variables, members of structures or classes.

Theconstspecifier declares a variable to be a constant and does not allow this variable's value to be changed in the process of program execution. It is allowed to initialize a variable once when declaring it.

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I meant only two options

int Arr[100]

or

#define r 100
int Arr[r]

For the rest ArrayResize

[Dmitriy Skub]

papaklass:
I don't get it. I put an EA on the chart and this message appears in the "Experts" tab. The Expert Advisor continues its work anyway. This is not an error, but a warning. A warning about what?

It is an error at runtime - it means a memory leak. Somewhere memory occupied by a string is not being freed. Most likely, it is a structure or class that is not deleted after new. You need to look through the code to be more specific.

[Valerii Mazurenko]

joo:

constants won't work either, there will be an error:

Access specifiers

Access specifiers tell the compiler how to access variables, members of structures or classes.

Theconstspecifier declares a variable to be a constant, and does not allow this variable's value to be changed in the process of program execution. It is allowed to initialize a variable once when declaring it.

A constant variable is not a constant! It is allowed to be initialized once, i.e., it is a variable for which memory is allocated.

The task of the constants is to be calculated and inserted into the code without occupying the memory at runtime.

The constant will be const AA=11.

Therefore the compiler will get sworn. If const AA=11, it won't complain.

[Виктор]

Can you tell me what the problem is?

On the last interval in ChannelPeriod = 100; there is a sharp shift upwards in the indicator readings, going beyond the last 100 bars everything shows normally.

Does anyone know how to fix it?

//+------------------------------------------------------------------+
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[])
  {
  //--- variables of indicator
  int i;
    
  CopyClose(Symbol1_Name,PERIOD_M30,0,rates_total,close_1);
  CopyClose(Symbol2_Name,PERIOD_M30,0,rates_total,close_2);
  
  //--- main cycle
  for(i=prev_calculated; i<rates_total; i++)
  {
    Last[i] = (Symbol1_Vol*Symbol1_K*close_1[i] -  Symbol2_Vol*Symbol2_K*close_2[i]);
  }
  
    // Считаем положение эквити относительно канала удвоенного среднеквадратичного отклонения
  double StdDev;
  for(i=prev_calculated; i<rates_total; i++) 
  {
    StdDev=MyStdDev(Last,ChannelPeriod,i);
    if(StdDev>0.00001) // Защита от отсутствия данных
      ExtStdDevBuffer[i]=(Last[i]+2*StdDev-iMAOnArrayMQL4(Last,0,ChannelPeriod,0,MODE_SMA,i))/(4*StdDev);
  }
  
  return(rates_total);
}

//-----------------------------------------------------------------------------------------
//-----------------------------------------------------------------------------------------
// Calculation StdDev -----------------------------------------------| 
// StdDev = SQRT (SUM [(S(i) - SMA(i))^2, N] / N)                    | 
double MyStdDev(double &array[], int BandsPeriod, int Index) 
{ 
  double ds, sum, center; 
    
  sum = 0; 
  center = iMAOnArrayMQL4(array,0,BandsPeriod,0,MODE_SMA,Index); 
  for(int i = 0; i < BandsPeriod; i++) 
  { 
    ds = array[Index+i] - center; 
    sum += ds * ds; 
  } 
  sum = MathSqrt (sum / BandsPeriod); 
  return (sum); 
}
//-----------------------------------------------------------------------------------------

//-----------------------------------------------------------------------------------------
double iMAOnArrayMQL4(double &array[], int total, int period, int ma_shift, int ma_method, int shift)
{
  double buf[],arr[];
  if(total==0) total=ArraySize(array);
  if(total>0 && total<=period) return(0);
  if(shift>total-period-ma_shift) return(0);
  switch(ma_method)
  {
    case MODE_SMA :
    {
      total=ArrayCopy(arr,array,0,shift+ma_shift,period);
      if(ArrayResize(buf,total)<0) return(0);
      double sum=0;
      int    i,pos=total-1;
      for(i=1;i<period;i++,pos--)
      sum+=arr[pos];
      while(pos>=0)
      {
        sum+=arr[pos];
        buf[pos]=sum/period;
        sum-=arr[pos+period-1];
        pos--;
      }
      return(buf[0]);
    }
    case MODE_EMA :
    {
      if(ArrayResize(buf,total)<0) return(0);
      double pr=2.0/(period+1);
      int    pos=total-2;
      while(pos>=0)
      {
        if(pos==total-2) buf[pos+1]=array[pos+1];
        buf[pos]=array[pos]*pr+buf[pos+1]*(1-pr);
        pos--;
      }
      return(buf[shift+ma_shift]);
    }
    case MODE_SMMA :
    {
      if(ArrayResize(buf,total)<0) return(0);
      double sum=0;
      int    i,k,pos;
      pos=total-period;
      while(pos>=0)
      {
        if(pos==total-period)
        {
          for(i=0,k=pos;i<period;i++,k++)
          {
            sum+=array[k];
            buf[k]=0;
          }
        }
        else sum=buf[pos+1]*(period-1)+array[pos];
        buf[pos]=sum/period;
        pos--;
      }
      return(buf[shift+ma_shift]);
    }
    case MODE_LWMA :
    {
      if(ArrayResize(buf,total)<0) return(0);
      double sum=0.0,lsum=0.0;
      double price;
      int    i,weight=0,pos=total-1;
      for(i=1;i<=period;i++,pos--)
      {
        price=array[pos];
        sum+=price*i;
        lsum+=price;
        weight+=i;
      }
      pos++;
      i=pos+period;
      while(pos>=0)
      {
        buf[pos]=sum/weight;
        if(pos==0) break;
        pos--;
        i--;
        price=array[pos];
        sum=sum-lsum+price*period;
        lsum-=array[i];
        lsum+=price;
      }
      return(buf[shift+ma_shift]);
    }
    default: return(0);
  }
  return(0);
}
//-----------------------------------------------------------------------------------------

[Виктор]

indicator

[[Deleted]]

Why, when I press the "Start" button, the tester does not test from the initial deposit level, but from the level where the last test ended. There is no such problem in 4. How to start testing from the initial deposit level?

[Aleksey Rodionov]

Please give me a direct link to download textbooks in PDF format because my phone browser can't see everything on the website

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Zeleniy:
Please give me a direct link where you can download textbooks in PDF format because my phone browser can't see everything on the website.

there are no textbooks, only the help.