Quote Originally Posted by Uwe
1) Custom scales are possible.

If you tell me more details about Qt/Qwt versions and what you want to do in detail, I should be able to help.

2) Multiple Y-Scales

Qwt supports 2 Y scales (left + right) out of the box. If you need more than 2 Y scales you need a very deep understanding how the Qwt classes work together. I know that a couple of people hacked such a beast, but I don't recommend to try it. Better try to find a solution with 2 scales only.

HTH,
Uwe
Thank you, Uwe.

1) I'm using Qt 4.1.3 open source edition and Qwt snapshot 20060130.

Generally what i have to do:

I have three arrays: index, parameter value and time. Parameter value and time are functions of index (time must be linear function). Because of noise in telemetry channel there are many errors in time data. It makes impossible to plot (time, value). I have to plot (index, value) and put time ticks (where it is possible) on the bottom scale.

Generally index is the real stable "time", but user must see minutes and seconds.

2) I think, variant with 2 Y scales is not mine. I need to plot 3 and more curves in that manner. If I will not be able to understand Qwt classes interaction it would be better to find another solution for me (such as multiple plots instead of multiple scales).