Hello,

I am new to Qwt and I do not find a way to draw only a part of a curve.
Let me explain more precisely.

I have huge data (multiple curves of 1 million points) to be plotted. To avoid duplicating data (which can be edited through a QTableView), I have a class inheriting QwtData for each Curve. These Curve objects are used by my table model linked with the QTableView.

Then I have created a QwtPlotCurve object for each curve, and call setData with my own QwtData.

Next, I call setAxisScale (and replot) regularly on my plot to display my curves with a "slidding window".

The problem is that 100000 points curves works quite well, but 1 millions ones are really not.
I have noticed that all the data are browsed even if only data between 30 to 100 (in X index) have to be displayed. I think that is the problem but I do not find a way to avoid that.

I have notice the draw function which take two parameters (from and to) but I do not know how to use it.

Any hint ? How can I boost all this stuff ?

Thanks in advance