@timob256 In general , there was one mistake , for some reason I thought that by setting the size of the vector , it would correct everything itself , but it turned out not to be so

void MainWindow::slotProcessDatagrams() { QByteArray baDatagram_in; do { baDatagram_in.resize(m_pudp_in->pendingDatagramSize()); m_pudp_in->readDatagram(baDatagram_in.data(), baDatagram_in.size()); } while(m_pudp_in->hasPendingDatagrams()); QDataStream in(&baDatagram_in, QIODevice::ReadOnly); in.setVersion(QDataStream::Qt_5_3); in >> str_priem; // принимаем сообщение str_x = str_priem.section(' ',0,0); str_y = str_priem.section(' ',1); if(my_int >= 80) { // clear firs element // x.pop_back(); // y.pop_back(); // x.removeLast(); // y.removeLast(); x.pop_front(); //последний из вектора y.pop_front(); x << str_x.toDouble(); y << str_y.toDouble(); } else { x << str_x.toDouble(); y << str_y.toDouble(); my_int = my_int + 1; } // чистим старое отрисовываем новое wGraphic->graph(0)->clear(); wGraphic->graph(0)->rescaleAxes(); // wGraphic->replot(); // Отрисовываем содержимое полотна wGraphic->graph(0)->setData(y,x); // Устанавливаем координаты точек графика wGraphic->replot(); // Отрисовываем содержимое полотна // Очищаем принятую строку str_priem.clear(); }

True, a new error jumped (for some reason the last and first point somehow connects, I don't know how to break)

введите сюда описание изображения

Hi,
Thanks for sharing your experience. I tried to lunch the code but it only shows a "crashed" error.
@romain-donze would you please (if possible) share this project for me? I'm also a newbie and trying to visualize some real time data in histograph chart.

Hi,

@WLOrion said in Introduction in Qwt:

I didn't know this behavior of the Qwt Classes.

This is nothing Qwt specific, it's part of the C++ basics.

As for tutorial, there's a nice online book that is in German but the author claims that online translator should give you a good enough result in your own language.

@CJha try to useOpenGL for series, for qml i use series.useOpenGL = true

Hi
It would be very easy to draw manually using QML or QPainter
but do you need zooming and other features QChart provides ?

@Yash001
Hi, i wish i knew the answer
but im fairly sure canvas()->width(); just returns the actual widget size and
not the zoomed area as such.

Had a look in the help but didnt find the answer on how to get the extent on a zoomed canvas.

Thanks for the support guys. I tried making a transparent QPixmap image using Qt::transparent fill for the axis and overlaying it onto my other QPixmap, however it didn't work properly. So I ended up just drawing directly onto the image itself. Not the most efficient method but it seems to work...

@aha_1980 Thank you alot Sir your answer was correct and helped to clean up the problem!

Regards

Thank you for your answer! I've yet to find a good introduction into QML for C++ developers, but I was a little put off by the somewhat convoluted approach as different tutorials either don't show any QML or only use it soley to develop a very simple application.

The main problem I'm struggling is with QML is the ability to generate a GUI based on some set preferences. In my case the amount of e.g tabs in the "Options" pane should be defined by the amount of video files which are currently loaded. Is this easily possible to programatically extend QML GUIs?

I suggest looking into QCustomPlot.