[guidata/guiqwt] CurvePlot with large number of CurveItems

[Pierre Raybaut]

Hi,


From guiqwt v2 (PyQwt) to guiqwt v3 (PythonQwt), we have clearly lost performance. Depending on the specific application, it may be acceptable (for most of our internal software based on guiqwt, that's the case). Know that the PythonQwt solution is temporary: it solves the obsolescence issue of PyQwt but it’s not as efficient.


In the near future (mid-2017), we will switch to a more permanent and satisfying solution
 that's Qt Charts. The guiqwt Library will be renamed to “plotpy”: the GitHub project already exists.


-Pierre





De : Vincent
Envoyé : ‎mardi‎ ‎30‎ ‎août‎ ‎2016 ‎07‎:‎54
À : guidata/guiqwt





Hi Pierre,

I had an application which was using Qwt5.
My typical use scenario was a QwtPlot with a large number of QwtPlotCurve. For example, 5000 curves (each with ~100 points) would not be unusual.
Zooming and reploting were fairly fast.

I have been trying to move to PythonQwt. I tried to keep it as simple as possible and to limit myself to a CurvePlot and CurveItems.
(there are no tools implemented)
After the change, it is at least 100 times slower for my particular scenario.

It seems that I would have to fall back even further down to qwt.QwtPlot and qwt.QwtPlotCurve (would this solve my speed issue?) but then I no longer have the zooming abilities. You documentation states "The following Qwt classes won't be reimplemented in qwt because more powerful features already exist in guiqwt: QwtPlotZoomer, QwtCounter, QwtEventPattern, QwtPicker, QwtPlotPicker."

Are there any existing examples of how to implement zooming directly to a qwt.QwtPlot?

Basically what I want is to plot thousands of lines and the ability to zoom with relatively good responsiveness. I do not need any: toolbars, item lists, per-line interactions, select tools, etc..

Is this something guiqwt/PythonQwt can do?

(I already know pyqtgraph is not fast enough)

Thanks
Vincent