QApplication a(argc, argv);
    qsrand(QTime(0, 0, 0).secsTo(QTime::currentTime()));

    //![1]
    QLineSeries *series = new QLineSeries();
    series->setColor(Qt::red);
    QLineSeries *series_2 = new QLineSeries();
    //![1]

    //![2]
    // data from http://www.swpc.noaa.gov/ftpdir/weekly/RecentIndices.txt
    // http://www.swpc.noaa.gov/ftpdir/weekly/README
    // http://www.weather.gov/disclaimer
    QFile sunSpots(":sun");
    if (!sunSpots.open(QIODevice::ReadOnly | QIODevice::Text)) {
        return 1;
    }

    QTextStream stream(&sunSpots);
    while (!stream.atEnd()) {
        QString line = stream.readLine();
        if (line.startsWith("#") || line.startsWith(":"))
            continue;
        QStringList values = line.split(" ", QString::SkipEmptyParts);
        QDateTime momentInTime;
        momentInTime.setDate(QDate(values[0].toInt(), values[1].toInt() , 15));
        series->append(momentInTime.toMSecsSinceEpoch(), values[2].toDouble());
        series_2->append(momentInTime.toMSecsSinceEpoch(), 0);
    }
    sunSpots.close();
    //![2]

    QAreaSeries* areaSeries = new QAreaSeries(series, series_2);
    areaSeries->setColor(Qt::green);

    //![3]
    QChart *chart = new QChart();

///*
// CASE 1: INCORRECT X axis
    chart->addSeries(areaSeries);
//*/
/*
// CASE 3: INCORRECT X axis
    chart->addSeries(series);
    chart->addSeries(areaSeries);
//*/
/*
// CASE 2: OK
    chart->addSeries(areaSeries);
    chart->addSeries(series);
//*/

    chart->legend()->hide();
    chart->setTitle("Sunspots count (by Space Weather Prediction Center)");
    //![3]

    //![4]
    QDateTimeAxis *axisX = new QDateTimeAxis;
    axisX->setTickCount(10);
    axisX->setFormat("MMM yyyy");
    axisX->setTitleText("Date");
    chart->addAxis(axisX, Qt::AlignBottom);
    series->attachAxis(axisX);
    areaSeries->attachAxis(axisX);

    QValueAxis *axisY = new QValueAxis;
    axisY->setLabelFormat("%i");
    axisY->setTitleText("Sunspots count");
    chart->addAxis(axisY, Qt::AlignLeft);
    series->attachAxis(axisY);
    areaSeries->attachAxis(axisY);
    //![4]

    //![5]
    QChartView *chartView = new QChartView(chart);
    chartView->setRenderHint(QPainter::Antialiasing);
    //![5]

    //![6]
    QMainWindow window;
    window.setCentralWidget(chartView);
    window.resize(820, 600);
    window.show();
    //![6]

    return a.exec();