Detecting peak value on realtime data stream

[viniltc]

Hi all,

This is a bit off topic question! but hope I get some feedback from this forum.

I'm using QCustomPlot to display realtime value from an IMU.

This is how I set the realtimeDataSlot:

void Settings::realtimeDataSlot(double x_acceleration_g, double y_acceleration_g, double z_acceleration_g, double z_acceleration_gnew)
{
    static QTime time(QTime::currentTime());
    // calculate two new data points:
    double key = time.elapsed()/1000.0; // time elapsed since start of demo, in seconds
    static double lastPointKey = 0;
    if (key-lastPointKey > 0.02) // at most add point every 20 ms
    {
      // add data to lines:
        ui->customPlot->graph(0)->addData(key, x_acceleration_g); // X axis
        ui->customPlot->graph(1)->addData(key, y_acceleration_g); // Y axis
        ui->customPlot->graph(2)->addData(key, z_acceleration_g); // Z axis
        ui->customPlot->graph(3)->addData(key, z_acceleration_gnew);

      lastPointKey = key;
    }
    // make key axis range scroll with the data (at a constant range size of 8):
    ui->customPlot->xAxis->setRange(key, 8, Qt::AlignRight);
    ui->customPlot->replot();

    // calculate frames per second:
    static double lastFpsKey;
    static int frameCount;
    ++frameCount;
    if (key-lastFpsKey >2) // average fps over 2 seconds
    {
      ui->statusbar->showMessage(
            QString("%1 FPS, Total Data points: %2")
            .arg(frameCount/(key-lastFpsKey), 0, 'f', 0)
            .arg(ui->customPlot->graph(0)->data()->size()+ui->customPlot->graph(1)->data()->size())
            , 0);
      lastFpsKey = key;
      frameCount = 0;
    }
}

which shows me as follows:

As a next step, I need to detect the peaks (I define peak as that value (positive values) more than 0.25 g at high rate.) in any axis, say for example in the above figure in the Y axis there are peak values which I need to detect and count. Can somebody show me a way to do this?

I need to mark peaks as follows:

[JKSH]

@viniltc said in Detecting peak value on realtime data stream:

I need to detect the peaks (I define peak as that value (positive values) more than 0.25 g at high rate.) in any axis, say for example in the above figure in the Y axis there are peak values which I need to detect and count. Can somebody show me a way to do this?

"Peak detection" is quite a big field.

You can start by reading up on peak detection algorithms, or using a peak detection library in your application: https://www.google.com/search?q=peak+detection+library+c%2B%2B

[JKSH]

Please inform readers if you cross-post to other forums: https://stackoverflow.com/questions/60543683/detecting-peak-value-on-realtime-data-stream

This is to make sure people don't spend time answering if you already found a solution.