Important: Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

Creating a chart with multiple datas



  • Hi everyone. I have 4 different txt files. I want to read them and add them on a chart with a timer at the same time.
    Is there any easiest way to do it?
    I create 4 different read file function, and im thiking creating 4 different display chart function. Is it silly?



  • @suslucoder said in Creating a chart with multiple datas:

    Is it silly

    If your files are similar, yes.
    (This got answered in your other threads. So I guess you dont need this one here?!)



  • @Pl45m4 is it correct?

    void MainWindow::Timer_Slot()
    {
        static float q_x=0;
        if(!queue.isEmpty())
        {
           double num=queue.dequeue();
           if (series->count()> 10)
                series->removePoints(0, 1);
           q_x += 0.1;
           series->append(q_x, num);
           chart->scroll(10, 0);
           chart->update();
           qDebug() << q_x << num;
         }
        
        static float q_x2=0;
        if(!queue2.isEmpty())
        {
           double num2=queue2.dequeue();
           if(series2->count()>10)
               series2->removePoints(0,1);
           q_x2 += 0.1;
           series2->append(q_x2, num2);
           chart->scroll(10, 0);
           chart->update();
           qDebug() << q_x2 << num2;
         }
        static float q_x3=0;
        if(!queue3.isEmpty())
        {
           double num3=queue3.dequeue();
           if(series3->count()>10)
               series3->removePoints(0,1);
           q_x3 += 0.1;
           series3->append(q_x3, num3);
           chart->scroll(10, 0);
           chart->update();
           qDebug() << q_x3 << num3;
         }
        
        static float q_x4=0;
        if(!queue4.isEmpty())
        {
           double num4=queue4.dequeue();
           if(series4->count()>10)
               series4->removePoints(0,1);
           q_x4 += 0.1;
           series4->append(q_x4, num4);
           chart->scroll(10, 0);
           //chart->update();
           qDebug() << q_x4 << num4;
         }
    }
    

  • Lifetime Qt Champion

    @suslucoder said in Creating a chart with multiple datas:

    is it correct?

    It's almost the same - you're still putting same code several times...
    Implement a method which gets the queue as parameter and put

    static float q_x=0;
        if(!queue.isEmpty())
        {
           double num=queue.dequeue();
           if (series->count()> 10)
                series->removePoints(0, 1);
           q_x += 0.1;
           series->append(q_x, num);
           chart->scroll(10, 0);
           chart->update();
           qDebug() << q_x << num;
         }
    

    in that method. Then simply call this method for each queue. Simple, isn't it?



  • @jsulm But i have 4 different queue, all them should be parameter?



  • @suslucoder

    You just merged your four functions into one. This doesn't change the fact that you have redundant code.

    @jsulm was faster :)



  • @Pl45m4 I've declared my queues in my header, does it matter?



  • @suslucoder said in Creating a chart with multiple datas:

    But i have 4 different queue, all them should be parameter?

    Just loop your queues.

    Bad:

    if(!queue1.isEmpty())
        {
           double num=queue1.dequeue();
        }
    if(!queue2.isEmpty())
        {
           double num=queue2.dequeue();
        }
    if(!queue3.isEmpty())
        {
           double num=queue3.dequeue();
        }
    

    Better:

    // Container with all your data or just pass one QQueue after another to your function
    QVector<QQueue<double> > data;
    
    for(int i = 0; i < data.size(); i++)
    {
       if(!data.at(i).isEmpty())
        {
           double num=data.at(i).dequeue();
           // ...
        }
    
    }
    

  • Lifetime Qt Champion

    @suslucoder said in Creating a chart with multiple datas:

    But i have 4 different queue, all them should be parameter?

    Yes, that's the idea:

    void MainWindow::someMethod(const QQueue<double> &queue)
    {
    ...
    }
    ...
    someMethod(queue);
    someMethod(queue1);
    someMethod(queue2);
    someMethod(queue3);
    

    Or do it like @Pl45m4 suggested.



  • @jsulm I understand it now. How about the reading part?
    Can i do it like queue part?


  • Lifetime Qt Champion

    @suslucoder said in Creating a chart with multiple datas:

    Can i do it like queue part?

    Why not?



  • @jsulm is it true?

    void MainWindow::ReadFile()
    {
          QFile file("/home/ilknur/Chart/Data1.txt");
          QFile file2("/home/ilknur/Chart/Data2.txt");
          QFile file3("/home/ilknur/Chart/Data3.txt");
          QFile file4("/home/ilknur/Chart/Data4.txt");
    
           if(file.open(QIODevice::ReadOnly))
           {
               QTextStream in(&file);
               while (!in.atEnd()) {
                   QString line = in.readLine();
                   QStringList list = line.split(QLatin1Char(' '), QString::SkipEmptyParts);
                   for (const QString &entry : list)
                   {
                       double num = entry.toDouble();
                       qDebug() << num;
                       queue.enqueue(num);
                   }
               }
           }
    
           if(file2.open(QIODevice::ReadOnly))
           {
               QTextStream in(&file2);
               while (!in.atEnd()) {
                   QString line2 = in.readLine();
                   QStringList list2 = line2.split(QLatin1Char(' '), QString::SkipEmptyParts);
                   for (const QString &entry : list2)
                   {
                       double num2 = entry.toDouble();
                       qDebug() << num2;
                       queue2.enqueue(num2);
                   }
               }
           }
    
           if(file3.open(QIODevice::ReadOnly))
           {
               QTextStream in(&file3);
               while (!in.atEnd()) {
                   QString line3 = in.readLine();
                   QStringList list3 = line3.split(QLatin1Char(' '), QString::SkipEmptyParts);
                   for (const QString &entry : list3)
                   {
                       double num3 = entry.toDouble();
                       qDebug() << num3;
                       queue3.enqueue(num3);
                   }
               }
           }
    
           if(file4.open(QIODevice::ReadOnly))
           {
               QTextStream in(&file4);
               while (!in.atEnd()) {
                   QString line4 = in.readLine();
                   QStringList list4 = line4.split(QLatin1Char(' '), QString::SkipEmptyParts);
                   for (const QString &entry : list4)
                   {
                       double num4 = entry.toDouble();
                       qDebug() << num4;
                       queue4.enqueue(num4);
                   }
               }
           }
    }
    

  • Lifetime Qt Champion

    @suslucoder said in Creating a chart with multiple datas:

    is it true?

    Of course not!
    You again copy same code several times.
    You already was shown how to do this correctly, I'm not going to explain the same second time...



  • @jsulm Can you explain it please for last time :(


  • Lifetime Qt Champion

    @suslucoder No, I did it above already...



  • @suslucoder

    QString file("/home/ilknur/Chart/Data1.txt");
    // ...
    // ...
    // all your files
    
    void MainWindow::ReadFile(QString file)
    {
      QFile(file);
    
           if(file.open(QIODevice::ReadOnly))
           {
               QTextStream in(&file);
               while (!in.atEnd()) {
                   QString line = in.readLine();
                   QStringList list = line.split(QLatin1Char(' '), QString::SkipEmptyParts);
                   for (const QString &entry : list)
                   {
                       double num = entry.toDouble();
                       qDebug() << num;
                        // pick correct queue here
                       queue.enqueue(num);
                   }
               }
           }
    }
    

    Then just call this read function ones for every file you want to read (with the file path as argument)

    ReadFile(file);
    

    Or even make a QStringList with all your filenames and call this function for every element of your list.

    To write "good" and clean code (OOP programming) , you'll need to stop that linear thinking (like script language). And even most of the script languages nowadays have functions, which you can define, to avoid writing the same code over and over and over again.

    Doing something X times != writing it X times.
    It's all about effiency (trying to avoid unnecessary things that will waste time, space and hardware ressources at runtime)



  • @Pl45m4 where should i store

    QString file("/home/ilknur/Chart/Data1.txt");
    // ...
    // ...
    // all your files
    
    

    And i have 4 different files. In this case,

    QString file("/home/ilknur/FourLineChart/Data1.txt");
    QString file2("/home/ilknur/FourLineChart/Data2.txt");
    QString file3("/home/ilknur/FourLineChart/Data3.txt");
    QString file4("/home/ilknur/FourLineChart/Data4.txt");
    


  • @suslucoder said in Creating a chart with multiple datas:

    where should i store

    Do you even read what we wrote?

    @Pl45m4 said in Creating a chart with multiple datas:

    Then just call this read function ones for every file you want to read (with the file path as argument)
    ReadFile(file);

    Or even make a QStringList with all your filenames and call this function for every element of your list.

    ^



  • @Pl45m4 said in

    Do you even read what we wrote?

    Of course. I just confused.

    QString file("/home/ilknur/FourLineChart/Data1.txt");
    QString file2("/home/ilknur/FourLineChart/Data2.txt");
    QString file3("/home/ilknur/FourLineChart/Data3.txt");
    QString file4("/home/ilknur/FourLineChart/Data4.txt");
    
    MainWindow::MainWindow(QWidget *parent)
       : QMainWindow(parent)
       , ui(new Ui::MainWindow)
    {
       ui->setupUi(this);
       CreateChart();
       ReadFile(file);
       ReadFile(file2);
       ReadFile(file3);
       ReadFile(file4);
    
    
    
    void MainWindow::ReadFile(QString file)
    {
           QFile(file);
    
          if(file.open(QIODevice::ReadOnly))
          {
              QTextStream in(&file);
              while (!in.atEnd()) {
                  QString line = in.readLine();
                  QStringList list = line.split(QLatin1Char(' '), QString::SkipEmptyParts);
                  for (const QString &entry : list)
                  {
                      double num = entry.toDouble();
                      qDebug() << num;
                       // pick correct queue here
                      queue.enqueue(num);
                  }
              }
          }
    }
    

    I miss something. But i dont know.


  • Lifetime Qt Champion

    @suslucoder I really don't understand why it is so hard! Please try to figure out such trivial things by yourself.

    MainWindow::MainWindow(QWidget *parent)
       : QMainWindow(parent)
       , ui(new Ui::MainWindow)
    {
       ui->setupUi(this);
       CreateChart();
       QString file("/home/ilknur/FourLineChart/Data1.txt");
       QString file2("/home/ilknur/FourLineChart/Data2.txt");
       QString file3("/home/ilknur/FourLineChart/Data3.txt");
       QString file4("/home/ilknur/FourLineChart/Data4.txt");
       ReadFile(file);
       ReadFile(file2);
       ReadFile(file3);
       ReadFile(file4);
    

    Or shorter:

    
    MainWindow::MainWindow(QWidget *parent)
       : QMainWindow(parent)
       , ui(new Ui::MainWindow)
    {
       ui->setupUi(this);
       CreateChart();
       ReadFile("/home/ilknur/FourLineChart/Data1.txt");
       ReadFile("/home/ilknur/FourLineChart/Data2.txt");
       ReadFile("/home/ilknur/FourLineChart/Data3.txt");
       ReadFile("/home/ilknur/FourLineChart/Data4.txt");
    


  • @jsulm said in Creating a chart with multiple datas:

    MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
    {
    ui->setupUi(this);
    CreateChart();
    ReadFile("/home/ilknur/FourLineChart/Data1.txt");
    ReadFile("/home/ilknur/FourLineChart/Data2.txt");
    ReadFile("/home/ilknur/FourLineChart/Data3.txt");
    ReadFile("/home/ilknur/FourLineChart/Data4.txt");

    I've do it in that way and i have

    void MainWindow::ReadFile(QString file)
    {
           QFile(file);
    
           if(file.open(QIODevice::ReadOnly))
           {
               QTextStream in(&file);
               while (!in.atEnd()) {
                   QString line = in.readLine();
                   QStringList list = line.split(QLatin1Char(' '), QString::SkipEmptyParts);
                   for (const QString &entry : list)
                   {
                       double num = entry.toDouble();
                       qDebug() << num;
                        // pick correct queue here
                       queue.enqueue(num);
                   }
               }
           }
    }
    

    I've got a lot of errors:

    : In member function ‘void MainWindow::ReadFile(QString)’:
    : error: declaration of ‘QFile file’ shadows a parameter
    error: declaration of ‘QFile file’ shadows a parameter
    QFile(file);
    ^


  • Lifetime Qt Champion

    @suslucoder said in Creating a chart with multiple datas:

    QFile(file);

    Again easy to fix:

    void MainWindow::ReadFile(QString filePath)
    {
           QFile file(filePath);
    
           if(file.open(QIODevice::ReadOnly))
    


  • @jsulm okey. We did it in that way. But i have

    void MainWindow::Timer_Slot()
    {
        static float q_x=0;
        static float q_x2=0;
        static float q_x3=0;
        static float q_x4=0;
    
        if(!queue.isEmpty())
            {
               double num=queue.dequeue();
               q_x += 0.1;
               series->append(q_x, num);
               chart->scroll(10, 0);
               chart->update();
               qDebug() << q_x << num;
    
            }
        if(!queue2.isEmpty())
            {
               double num2=queue2.dequeue();
               q_x2 += 0.1;
               series2->append(q_x2, num2);
               chart->scroll(10, 0);
               chart->update();
               qDebug() << q_x2 << num2;
    
    
            }
        if(!queue3.isEmpty())
            {
               double num3=queue3.dequeue();
               q_x3 += 0.1;
               series3->append(q_x3, num3);
               chart->scroll(10, 0);
               chart->update();
            }
    
        if(!queue4.isEmpty())
            {
               double num4=queue4.dequeue();
               q_x4 += 0.1;
               series4->append(q_x4, num4);
               chart->scroll(10, 0);
               chart->update();
            }
    }
    

    What will happen my other queues, in ReadFile() ?


  • Lifetime Qt Champion

    @suslucoder said in Creating a chart with multiple datas:

    What will happen my other queues, in ReadFile() ?

    Can't you simply use one queue?
    If not then extend the readFile() method:

    void MainWindow::ReadFile(const QString &file, QQueue<double> &queue)
    {
    ...
    

    And pass queue as second parameter.



  • @jsulm said in Creating a chart with multiple datas:

    Can't you simply use one queue?

    When i use one queue, how can i differ my datas?
    Txt files have different values, and i will show all of them in a line chart with different color


  • Lifetime Qt Champion

    @suslucoder Then do like I suggested:

    void MainWindow::ReadFile(const QString &file, QQueue<double> &queue)
    {
    ...
    }
    ...
    ReadFile("/home/ilknur/FourLineChart/Data1.txt", queue);
    ReadFile("/home/ilknur/FourLineChart/Data2.txt", queue1);
    ReadFile("/home/ilknur/FourLineChart/Data3.txt", queue2);
    ReadFile("/home/ilknur/FourLineChart/Data4.txt", queue3);
    


  • @jsulm in .h file i have

     ```
     QQueue<double> queue;
     QQueue<double> queue2;
     QQueue<double> queue3;
     QQueue<double> queue4;
    
    
    Should i delete them?

  • Lifetime Qt Champion

    @suslucoder said in Creating a chart with multiple datas:

    Should i delete them?

    No. Why would you?



  • This post is deleted!

Log in to reply