qlineseries with multiple data points

[rafael]

I have a qlineseries with 7 million data points.

if(m_LineSeries->points().isEmpty())
       {
           ConvertToLineSeries(m_Pressures,m_LineSeries);

          QtCharts::QChart *chart = new QtCharts::QChart();
          chart->legend()->hide();
          chart->addSeries(m_LineSeries);
          chart->createDefaultAxes();
          chart->setTitle("Simple line chart example");

          QtCharts::QChartView *chartView = new QtCharts::QChartView(chart);
          chartView->setRenderHint(QPainter::Antialiasing);

          ui->layout->addWidget(chartView);
       }

The main window is very slow to respond. I am trying to resize the mainwindow and it keeps saying not responding.
How can i make it so that the window stays reponsive, even just clicking on the window makes the program freeze for a few seconds before i can do anything.

[JonB]

@rafael
The answer is: since you don't want to plot 7 million data points on the screen (right?), you want to thin out how many you create....

[Pl45m4]

@rafael

There is no way / reason to display 7 million data points at the same time in a lineseries on the screen.

Use zoom features or down-sampling strategies to reduce the amout of samples plotted at a time.

[rafael]

I had a test program in python and i was using matplotlib to plot the data.
i guess matplotlib does some downsampling in the background, because the plots are responsive.

I was just using the same technique here.
load all the data points, and plot.

do you know of a library that does this, downsample and upsample data?

void ConvertToLineSeries(std::vector<Pressure> data, QtCharts::QLineSeries *series)
{
    int count = 0;

    for(auto &p : data)
    {       

        if(count == (32 * 10))
        {
            p.GetTimeStamp();
            p.GetPressure();

            series->append(p.GetTimeStamp().time_since_epoch().count(),p.GetPressure());

            count = 0;
        }

        count++;

    }

    qDebug() << series->points()[0];
}

seems to be better , i'm only displaying data every 320 samples which reduced it to 21,875.