qwt raster data with missing values

[SJPDS]

I'd like to display some data in Qwt plot. However, when I try to do that using Qwt, it appears I have no way of displaying some missing values without affecting the scale for the plot. Am I missing something?

[Uwe]

The range of the axis scale is only related to the plot items ( and their data ), when auto scaling is enabled. But even then it would depend on the bounding rectangle and not whether points are missing ( NaN values ) inside of the raster data.

Uwe

[SJPDS]

Thanks, Uwe. If I turn off the auto scaling then, it should work, if I understand you right. Pardon my beginner questions, but how do I turn off auto scaling?

[Uwe]

By setting a scale explicitly - see:

http://qwt.sourceforge.net/class_qwt...95d0c16924eed6
http://qwt.sourceforge.net/class_qwt...2fa4f6378c225a
http://qwt.sourceforge.net/class_qwt...440fceead50432

Also consider using the real bounding rectangle ( only where you have values ). In situations, where the rectangle is inside the visible the performance of the image composition will be better.

Uwe