setAxisMaxMajor not respected by log scale engine?

Hi all, I'm plotting a curve using a QwtLogScaleEngine for the xTop axis:

QwtLogScaleEngine *engine = new QwtLogScaleEngine();
setAxisScaleEngine(QwtPlot::xTop, engine);

I'm also trying to use setAxisMaxMajor(QwtPlot::xTop, 2) to limit the number of major scale intervals to 2.

But the result is that I still get 3 major intervals on the xTop axis:

Attachment 12124

Is setAxisMaxMajor(..) not supposed to take effect when using a QwtLogScaleEngine ?

Thanks in advance.

QwtPlot::setAxisMaxMajor() is a limit for the ticks - the number of intervals is then always one more.

What you might want to do is:

Code:

---

setAxisMaxMajor(QwtPlot::xTop, numIntervals - 1 );

---

Uwe

Aha, I see. I think the docs might need updating. They currently say: "Set the maximum number of major scale intervals for a specified axis".

But I'm still a little confused. The number of intervals should be one less than the number of ticks, shouldn't it?

Or are the axis start/end not counted as "ticks" in this case? If so I guess I should pass 1 as parameter. I'll give it a try when I'm back at work in ~20 min.

Thanks for the help!