Plot does not refresh

[Mat12345]

Hi everyone !

I'm developing an app which plots data using Qwt (5.2.0) and Qt 4.5.3.

My data is contained in two "vector<vector<double> >" matrixes.

I have a QMainWindow, with QSubWindows containing each a QwtPlot and some QComboBoxes to set the combination of line/column to plot (fixed line or fixed column etc).

The matrixes are in a class which is only instanciated once.
So I have created a class, which inherits QwtData and uses the data in the matrixes for the output of "double x(size_t i)" and "double y(size_t i)". Now if I change a parameter in my data class, I want the plot to redraw/refresh.

I tried "QwtPlot::replot()", "QwtPlotItem::itemChanged()" but it doesn't work.

Thanks in advance,
M.

[Uwe]

Depends on the implementation of YourData::copy. If it is implemented as deep copy you have to call curve->setData() after each value change. Otherwise QwtPlot::replot should do what you want. ( QwtPlotItem::itemChanged() has only an effect, for auto-replotting ).

Uwe

[Mat12345]

Hi Uwe,

Thank you for your reply.

My implementation of QwtData::copy is indeed a deep copy.
Even after resetting the Data (QwtPlotCurve::setData), replotting (QwtPlot::replot), detaching and reattaching the QwtPlotCurve, nothing changes, the plot remains the same (the state of my data class is taken account of the first time, but then changing it doesn't yield the replot).

I'll try coding something quickly to show you,

Thanks,
M.

[Mat12345]

Hi again,

Ok check the attachment out.

It should double both scales at each button press.

If i understand why this small code doesn't work, i think i understand why my code doesn't work.

Thanks again,
M.