QwtPlotSpectrogram tutorial

[enricong]

I'm new to QWT and am having trouble understanding how to use it and havent found any examples. The userguide on the website seems to be just a class listing which is useful but not quite enough for me to get started as it doesnt really explain how to use many of the classes.

I have a 2D dataset X, Y and an intensity value (but with some points missing). It sounds like I want to use QwtPlotSpectrogram to get the output I want.
I don't understand how I set the 2d dataset to the qwtplotspectrogram and then plot it on my qplot.