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  4. How can i use 2 QTimer? One is for counting and the other one is displaying
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How can i use 2 QTimer? One is for counting and the other one is displaying

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  • ? A Former User

    @koahnig im new on this platform and qt. Sorry for my mistakes. I run the code but when i clicked the start it didnt count :(

    K Offline
    K Offline
    koahnig
    wrote on last edited by
    #4

    @suslucoder

    You would need to publish all files.

    Probably your push button is not connected to the slot function.

    Vote the answer(s) that helped you to solve your issue(s)

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    • ? Offline
      ? Offline
      A Former User
      wrote on last edited by
      #5

      I've solved to problem. Thanks a lot. What if i want to connect my timer to a chart, which is read the data from txt file and according to timer create a chart

      mrjjM 1 Reply Last reply
      0
      • ? A Former User

        I've solved to problem. Thanks a lot. What if i want to connect my timer to a chart, which is read the data from txt file and according to timer create a chart

        mrjjM Offline
        mrjjM Offline
        mrjj
        Lifetime Qt Champion
        wrote on last edited by
        #6

        @suslucoder
        Hi
        You dont really connect the timer to a chart.
        You connect it to a slot.
        In that slot you can access a chart you have on your main window to add new data for it to plot.

        So the plan is to only read a line from the file each timer triggers ?
        Im asking as normally one would read whole file and plot at once so i
        wonder what the goal/task is.

        ? 1 Reply Last reply
        3
        • mrjjM mrjj

          @suslucoder
          Hi
          You dont really connect the timer to a chart.
          You connect it to a slot.
          In that slot you can access a chart you have on your main window to add new data for it to plot.

          So the plan is to only read a line from the file each timer triggers ?
          Im asking as normally one would read whole file and plot at once so i
          wonder what the goal/task is.

          ? Offline
          ? Offline
          A Former User
          wrote on last edited by
          #7

          @mrjj actually i want to a real time chart. Datas can read at once. But they should add into chart in a time interval. For example, in every sec, add 20 data on chart. On, in 20 sec add 20 data to the chart. It should be real time

          mrjjM 1 Reply Last reply
          0
          • ? A Former User

            @mrjj actually i want to a real time chart. Datas can read at once. But they should add into chart in a time interval. For example, in every sec, add 20 data on chart. On, in 20 sec add 20 data to the chart. It should be real time

            mrjjM Offline
            mrjjM Offline
            mrjj
            Lifetime Qt Champion
            wrote on last edited by
            #8

            @suslucoder
            Hi
            How big is this file ?

            You could read it to a StringList and then use a variable to keep track of how far into the list you are
            so each time , timer triggers, then you take next 20 from list and give to the chart.

            ? 1 Reply Last reply
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            • mrjjM mrjj

              @suslucoder
              Hi
              How big is this file ?

              You could read it to a StringList and then use a variable to keep track of how far into the list you are
              so each time , timer triggers, then you take next 20 from list and give to the chart.

              ? Offline
              ? Offline
              A Former User
              wrote on last edited by
              #9

              @mrjj it is not so big. It has 20 or 40 line at all. Here is my reading file and creating a chart code. I have a timer but it is another project. I cannot create a connection between them :(

              #include <QtWidgets/QApplication>
              #include <QtWidgets/QMainWindow>
              #include <QtCharts/QChartView>
              #include <QtCharts/QLineSeries>
              #include <QtCore/QDateTime>
              #include <QtCharts/QDateTimeAxis>
              #include <QtCore/QFile>
              #include <QtCore/QTextStream>
              #include <QtCore/QDebug>
              #include <QtCharts/QValueAxis>
              #include <QQueue>
              
              QT_CHARTS_USE_NAMESPACE
              
              int main(int argc, char *argv[])
              {
                  QApplication a(argc, argv);  //QApplication ana olay döngüsünü içeren bir QT sınıfıdır. Bu kodu çağırdığımızda, yapıcısını argc ve argv olarak çağırıp
                                               //yeni bir nesne oluşturuyoruz.
              
              
                  QLineSeries *series = new QLineSeries(); //
              
              
              
                  QFile sunSpots(":sun");
                  if (!sunSpots.open(QIODevice::ReadOnly | QIODevice::Text)) {
                      return 1;
                  }
              
                  QTextStream stream(&sunSpots);
                  while (!stream.atEnd()) {
                      QString line = stream.readLine(); //satır satır okuma yap
                      if (line.startsWith("#") || line.startsWith(":")) //# veya : ile başlayıyorsa devam et, hiçbir şey yapma
                          continue;
                      QStringList values = line.split(QLatin1Char(' '), Qt::SkipEmptyParts); //boşlukları ayırıyor ve atıyor
                      QDateTime momentInTime;
                      momentInTime.setDate(QDate(values[0].toInt(), values[1].toInt() , 15)); //?
                      qDebug()<< momentInTime;
                      series->append(momentInTime.toMSecsSinceEpoch(), values[2].toDouble());
                  }
                  sunSpots.close(); //açtığımız txt dosyasını kapat
              
              
                  QChart *chart = new QChart(); //bir chart oluşturabilmek için QChart sınıfından bir instace oluşturuyoruz.
                  chart->addSeries(series); //dosyadan okuduğumuz verileri chart'a ekliyoruz.
                  chart->legend()->hide();  //show ile de olur, set,
                  chart->setTitle("Sunspots count (by Space Weather Prediction Center)");
              
              
              
                QDateTimeAxis *axisX = new QDateTimeAxis; //eksenleri ayarlıyoruz. QLineSeries
                axisX->setTickCount(10); //x ekseninde gösterilecek veri sayısı.
                axisX->setFormat("MMM yyyy"); //format ay ve yıl olacak.
                axisX->setTitleText("Date"); //x ekseninin altndaki başlık date olacak.
                chart->addAxis(axisX, Qt::AlignBottom);
               series->attachAxis(axisX); //seriye eklediğimiz bilgileri x eksenine koyuyoruz.
              
               QValueAxis *axisY = new QValueAxis;
               axisY->setLabelFormat("%i");
                axisY->setTitleText("Sunspots count");
                chart->addAxis(axisY, Qt::AlignLeft);
               series->attachAxis(axisY);
              
                 QChartView *chartView = new QChartView(chart);
                chartView->setRenderHint(QPainter::Antialiasing);
              
              
              
                QMainWindow window;
                  window.setCentralWidget(chartView);
                 window.resize(820, 600);
                 window.show();
              
              
                  return a.exec();
              }
              
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              • mrjjM Offline
                mrjjM Offline
                mrjj
                Lifetime Qt Champion
                wrote on last edited by
                #10

                Hi
                Well you already read the file and add the data.
                in
                series->append(momentInTime.toMSecsSinceEpoch(), values[2].toDouble());

                so instead of this, you want to do it in steps ?

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                0
                • ? Offline
                  ? Offline
                  A Former User
                  wrote on last edited by
                  #11

                  yes, exactly

                  mrjjM 1 Reply Last reply
                  0
                  • ? A Former User

                    yes, exactly

                    mrjjM Offline
                    mrjjM Offline
                    mrjj
                    Lifetime Qt Champion
                    wrote on last edited by
                    #12

                    @suslucoder
                    Hi
                    Well then instead of appending to the series object,
                    then make a list and add to that list instead.
                    So we read file to a list.
                    do you know std::vector ?

                    Then make a new timer and connect to a lambda slot .
                    in the slot, you call series->append to add the data in steps.
                    make sure you dont run out of list end.

                    ? 1 Reply Last reply
                    0
                    • mrjjM mrjj

                      @suslucoder
                      Hi
                      Well then instead of appending to the series object,
                      then make a list and add to that list instead.
                      So we read file to a list.
                      do you know std::vector ?

                      Then make a new timer and connect to a lambda slot .
                      in the slot, you call series->append to add the data in steps.
                      make sure you dont run out of list end.

                      ? Offline
                      ? Offline
                      A Former User
                      wrote on last edited by
                      #13

                      do you know std::vector ?
                      I dont know but im trying to do this.
                      Thank you

                      mrjjM 1 Reply Last reply
                      0
                      • ? A Former User

                        do you know std::vector ?
                        I dont know but im trying to do this.
                        Thank you

                        mrjjM Offline
                        mrjjM Offline
                        mrjj
                        Lifetime Qt Champion
                        wrote on last edited by
                        #14

                        @suslucoder
                        Hi
                        well i was thinking something like

                        struct Data {
                        qint64 timestamp;
                        double value;
                        };
                        
                        std::vector<Data> thelist;
                        

                        would allow you to store what you now add directly.
                        i mean this line
                        series->append(momentInTime.toMSecsSinceEpoch(), values[2].toDouble());

                        Im only guessing since you seems to read timestamp from file too. but not sure what you do with momentInTime variable.

                        Once in a list, you can take data from that and add step by step.

                        ? 1 Reply Last reply
                        0
                        • mrjjM mrjj

                          @suslucoder
                          Hi
                          well i was thinking something like

                          struct Data {
                          qint64 timestamp;
                          double value;
                          };
                          
                          std::vector<Data> thelist;
                          

                          would allow you to store what you now add directly.
                          i mean this line
                          series->append(momentInTime.toMSecsSinceEpoch(), values[2].toDouble());

                          Im only guessing since you seems to read timestamp from file too. but not sure what you do with momentInTime variable.

                          Once in a list, you can take data from that and add step by step.

                          ? Offline
                          ? Offline
                          A Former User
                          wrote on last edited by
                          #15

                          @mrjj I will try

                          mrjjM 1 Reply Last reply
                          0
                          • ? A Former User

                            @mrjj I will try

                            mrjjM Offline
                            mrjjM Offline
                            mrjj
                            Lifetime Qt Champion
                            wrote on last edited by
                            #16

                            @suslucoder
                            Ok so instead fo this line
                            series->append(momentInTime.toMSecsSinceEpoch(), values[2].toDouble());
                            you do
                            Data tmp;
                            tmp.timestamp = momentInTime.toMSecsSinceEpoch();
                            tmp.value = values[2].toDouble();
                            thelist.push_back(tmp);

                            To store in list.

                            1 Reply Last reply
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