How to customize the X axis?

[lvdong]

for example:
x y
1 1
2 2
3 3
10 10
20 20
30 30
40 40
50 50

how to set the X axis scale to be 1 2, where 1 at x=2, and 2 at x=30

i am new to qwt, please help, thanks!

[Uwe]

If you want to have irregular scales use QwtPlot::setAxisScaleDiv().

Uwe

[lvdong]

thanks, got it.