[ARCHIVE!] Any rookie question, so as not to clutter up the forum. Professionals, don't pass by. Can't go anywhere without you - 4. - page 428

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impus:

Good afternoon, gentlemen.

I am a beginner and I have a question: how do I optimise my robot correctly?

I know which buttons and checkboxes need to be pressed in order to run the strategy tester.

I am wondering, how to figure out what period to optimize it for? How to figure out how long the EA will work "well"?

How can we calculate it? It's not just the method of insight that can work...

See references (from my (seventh on the page) post) here, in particular: "Robert Pardo "Developing, testing and optimising trading systems for the stock trader".
 

Hello.

Can you tell me what changes need to be made to the code. I want the histogram to display only the values for bearish bars.

The indicator itself https://www.mql5.com/ru/code/8920

int start()
{
    if (OpenTime != iOpen(Symbol(), PERIOD_M1, 0))
    {
        OpenTime = iOpen(Symbol(), PERIOD_M1, 0);

        int n, MaxVolume;
        double max = iHigh(Symbol(), PERIOD_M1, iHighest(Symbol(), PERIOD_M1, MODE_HIGH, MinutesCount, 0));
        double min = iLow(Symbol(), PERIOD_M1, iLowest(Symbol(), PERIOD_M1, MODE_LOW, MinutesCount, 0));
        int items = MathRound((max-min) / PricePoint);

        if (max == 0)
        {
            Alert("There is no minutes data. Please download M1.");
            return (0);
        }

        ArrayResize(Hist, items);      
        ArrayInitialize(Hist, 0);
        for (int i = 1; i <= MinutesCount; i++)
        {
            n = MathRound((iClose(Symbol(), PERIOD_M1, i)-min) / PricePoint);
            Hist[n] += (iVolume(Symbol(), PERIOD_M1, i));    
        }

        MaxVolume = Hist[ArrayMaximum(Hist)];
        DeleteObjects();
        for (i = 0; i <= items; i++)
        {
            DrawLine(i, min + i*PricePoint, Hist[i], MaxVolume);
        }
    }
        return(0);
}
 

Good afternoon. Question about a file pointer... In the MQL4 book, found at MQL4.community, in the "Standard Functions" section, there is an example of the script "File Operations", which is intended for reading data from a file and displaying graphical objects in a symbol window:

//--------------------------------------------------------------------
// timetablenews.mq4
// Предназначен для использования в качестве примера в учебнике MQL4.
//--------------------------------------------------------------- 1 --
int start()                            // Спец. функция start
  {
//--------------------------------------------------------------- 2 --
   int Handle,                         // Файловый описатель
       Stl;                            // Стиль вертикальной линии
   string File_Name="News.csv",        // Имя файла
          Obj_Name,                    // Bмя объекта
          Instr,                       // Название валюты
          One,Two,                     // 1я и 2я чать названия инстр.
          Text,                        // Текст описания события
          Str_DtTm;                    // Дата и время события(строка)
   datetime Dat_DtTm;                  // Дата и время события(дата)
   color Col;                          // Цвет вертикальной линии
//--------------------------------------------------------------- 3 --
   Handle=FileOpen(File_Name,FILE_CSV|FILE_READ,";");// Открытие файла
   if(Handle<0)                        // Неудача при открытии файла
     {
      if(GetLastError()==4103)         // Если файла не существует,..
         Alert("Нет файла с именем ",File_Name);//.. извещаем трейдера 
      else                             // При любой другой ошибке..
         Alert("Ошибка при открытии файла ",File_Name);//..такое сообщ
      PlaySound("Bzrrr.wav");          // Звуковое сопровождение
      return;                          // Выход из start()      
     }
//--------------------------------------------------------------- 4 --
   while(FileIsEnding(Handle)==false)// До тех пор, пока файловый ..
     {                                // ..указатель не в конце файла
      //--------------------------------------------------------- 5 --
      Str_DtTm =FileReadString(Handle);// Дата и время события(дата)
      Text     =FileReadString(Handle);// Текст описания события
      if(FileIsEnding(Handle)==true)   // Файловый указатель в конце
         break;                        // Выход из чтения и рисования
      //--------------------------------------------------------- 6 --
      Dat_DtTm =StrToTime(Str_DtTm);   // Преобразование типа данных
      Instr    =StringSubstr(Text,0,3);// Извлекаем первые 3 символа
      One=StringSubstr(Symbol(),0,3);// Извлекаем первые 3 символа
      Two=StringSubstr(Symbol(),3,3);// Извлекаем вторые 3 символа
      Stl=STYLE_DOT;                   // Для всех - стиль пунктир
      Col=DarkOrange;                  // Для всех - цвет такой
      if(Instr==One || Instr==Two)     // А для событий по нашему ..
        {                             // .. финансовому инструменту..
         Stl=STYLE_SOLID;              // .. такой стиль..
         Col=Red;                      // .. и такой цвет верт. линии
        }
      //--------------------------------------------------------- 7 --
      Obj_Name="News_Line  "+Str_DtTm;     // Имя объекта
      ObjectCreate(Obj_Name,OBJ_VLINE,0,Dat_DtTm,0);//Создаем объект..
      ObjectSet(Obj_Name,OBJPROP_COLOR, Col);       // ..и его цвет,..
      ObjectSet(Obj_Name,OBJPROP_STYLE, Stl);       // ..стиль..
      ObjectSetText(Obj_Name,Text,10);              // ..и описание 
     }
//--------------------------------------------------------------- 8 --
   FileClose( Handle );                // Закрываем файл
   PlaySound("bulk.wav");              // Звуковое сопровождение
   WindowRedraw();                     // Перерисовываем объекты
   return;                             // Выход из start()
  }
//--------------------------------------------------------------- 9 --

Below, when analyzing this script in the Book on MQL4, the following phrase is given: "if the specified check (the last 2 lines in block 5-6) is removed, an extra object will be created at runtime. And only after that, the while loop's termination condition will trigger and control will be passed to block 8-9".

Do I understand it correctly? A file pointer is NOT INFLOWED BY TEXT SIGNS (for example: text| where | is a file pointer), but is a pointer WITH EXPRESSION, for example: text where k is the "to" character, k-th is highlighted by a file pointer. This explains the need for strings (see p.164):

      if(FileIsEnding(Handle)==true)   // Файловый указатель в конце
         break;                        // Выход из чтения и рисования
      //--------------------------------------------------------- 6 --

Indeed. On penultimate iteration, after creating LAST object

2007.05.11 18:30;JPY

the file pointer is at the position of the last object, i.e:

2007.05.11 18:30;JPY IndustrialManufacture

(where o is the "o" character, k is the file index). Then when passing control to while statement header, FileIsEnding(handle) function will obviously return true, because file pointer is NOT at end of file, but at LAST character of that file. Then when the first two lines are executed, the file pointer will move to empty space and if there are no lines

      if(FileIsEnding(Handle)==true)   // Файловый указатель в конце
         break;                        // Выход из чтения и рисования
      //--------------------------------------------------------- 6 --

the script will create a graphic (i.e. a line) with an empty description and a time coordinate that corresponds to 0. This is what is meant in the phrase: "if the specified check (the last 2 lines in block 5-6) is removed, then an extra object will be created at runtime. "

Question: do I understand correctly:

a) the definition of a file pointer;

b) the meaning of the phrase "If the specified check (the last 2 lines in block 5-6) is deleted, then an extra object will be created at program execution.And only after that the while loop's end condition will be triggered and control will be passed to block 8-9".

P.S. In order not to litter the forum, thank you in advance for your answer

 
People!!! Please give me the function to open the hour bar (I need to determine the Open of the previous candle) and if (TimeMinute(TimeCurrent())==m && TimeSeconds(TimeCurrent())==n) for some reason it does not work putting m=1 n=1 but I beg you, who cares...
 
stater:
People!!! Please give me the function to open the hour bar (I need to determine the Open of the previous candle) and if (TimeMinute(TimeCurrent())==m && TimeSeconds(TimeCurrent())==n) for some reason it does not work putting m=1 n=1 but I beg you, who cares...
https://docs.mql4.com/ru/series
 
Zhunko:
https://docs.mql4.com/ru/series

thanks for your feedback, but I don't understand which function is used to know if an hour candle has opened....
 
stater:
thanks for your feedback, but I don't understand which function is used to know if an hour candle has opened....

iTime
 
The advisor keeps giving out error 0, can you tell me how to check what's causing it, how to find this place?
 
FAQ:

iTime
Thank you for your patience!
 
Egori4:
EA keeps giving out error 0, advise - how to check what is causing it, how to find this place?

Error 0 is that there are no errors.

Stop doing Print (alert) =)

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