Read data from txt and plot it in real time

[deleted286]

I have an txt file. I want to do this in order;
First read the data from txt file and than plot it in an order. Here is my code, it doesnt work but i dont know why. Im so new on qt platform. I'm open to any suggestions.

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QtWidgets/QApplication>
#include <QtWidgets/QMainWindow>
#include <QTimer>
#include <QtCharts/QLineSeries>
#include <QtCore/QFile>
#include <QtCore/QTextStream>
#include <QtCore/QDebug>
#include <QtCharts/QValueAxis>
#include <QtCharts/QChartView>
#include <QtCore/QDateTime>
#include <QtCharts/QDateTimeAxis>

QT_CHARTS_USE_NAMESPACE

using namespace QtCharts;
MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);


    QTimer *t1 = new QTimer(this);
    connect(t1, SIGNAL(timeout()), this, SLOT(sunSpot()));
    t1->start(0);

    QTimer *t2 = new QTimer(this);
    connect(t2, SIGNAL(timeout()), this, SLOT(chart()));

    t2->start(5);


QLineSeries *series = new QLineSeries();


QFile sunSpots(":sun");

if (!sunSpots.open(QIODevice::ReadOnly | QIODevice::Text)) {

}

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();

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();


}



//MainWindow::~MainWindow()
//{


//    delete ui;

//}

[Christian Ehrlicher]

@suslucoder said in Read data from txt and plot it in real time:

QMainWindow window;
window.setCentralWidget(chartView);
window.resize(820, 600);
window.show();

c++ basics - how long do you think does this object lives?

[deleted286]

I'm trying to learn c++ and qt also. I've only been working for 2 days.

[Christian Ehrlicher]

Then I would not start with such a complex problem but go for a c++ book and learn the basics. Sorry.

[deleted286]

@Christian-Ehrlicher You are free to not help. I'm sure there will be others willing to help. Thanks for your suggestion

[JonB]

@suslucoder
Your MainWindow is derived from QMainWindow. Yet within its constructor you create an instance of/local variable QMainWindow. This does not make sense.

[deleted286]

@JonB I got it thank you. Is there any easy way to read data from txt and plot it?

[JonB]

@suslucoder
Well, this has nothing at all to do with reading text or plotting. First you need to get a sensible main window going.

At a guess you intend your MainWindow to be the main window; you don't want to create some other main window instance. So where you have

  QMainWindow window;
  window.setCentralWidget(chartView);
  window.resize(820, 600);
  window.show();

you probably want to do this on your this instance:

  setCentralWidget(chartView);
  resize(820, 600);
  show();

And then your C++ main() is the place to declare

MainWindow mainWindow;

[deleted286]

Okey thank u