Realtime Chart: QML or C++ ? need advice!

[MAthias_Va]

I want to plot a real time chart, and add some features to it like save the data, change scale, zoom and change colors, I have two options to follow either QML based like: https://doc.qt.io/qt-5/qtcharts-qmloscilloscope-example.html

or C++ based like: https://doc.qt.io/qt-5.11/qtcharts-dynamicspline-example.html

I am confused which one should I follow?

[kuzulis]

Don't use QtCharts at all for realtime, it is a bad idea. If you need to do it in QML, then I can say, that there are a bad news. You need to create an own implementation (based on QSGNodes) from scratch (AFAIK), or to use e.g. this.

But if you need in QtWidgets, then a best option (IMHO) - it is to use the Qwt library.

PS: QtCharts is ugly, slow, eats the memory, loads the CPU and etc. It can be used only for a static charts. I don't understand why it has been released at all (even worse under GPLv3). I'm personally don't recomment to use it, unfortuanelly.

[MAthias_Va]

Thanks for the advice

[milan]

hello @kuzulis @MAthias_Va. I am also facing exactly same problem. I tried to run the qtquickplot, but it cannot be run. Have you any success working with it?

[MAthias_Va]

@kuzulis yes I just test it also, and it looks not working, Can you have a look on it!

[kuzulis]

I did not tried qtquickplot. You can look on this blog. Or try to find another "charts library"... Or to create an own...

PS: I just pointed out that QtCharts is not a best choose. But I don't know other alternatives in QML.

[MAthias_Va]

ok thanks again @kuzulis

[Gojir4]

@MAthias_Va Hi,

Both C++ and QML solution are the same, QML is based on the C++ backend. So you can use the one which is best for you.

[asterixxx]

https://www.youtube.com/watch?v=lXXUxy5Opds&t=1s