I'm using my own logic to have customized ticks on my scale:

Qt Code: 
  1. // mTimeScaleDiv is a AxisScaleDiv member
  2. mTimeScaleDiv.invalidate();
  3. mTimeScaleDiv.setInterval(0, 40000);
  4. QList<double> majorTicks;
  5. QList<double> minorTicks;
  6.  
  7. for (int i = 0; i < (20 + 1); i++)
  8. {
  9. 	if (i % 5 == 0)
  10. 	{
  11. 		majorTicks.append(i * 2000);
  12. 	}
  13. 	else
  14. 	{
  15. 		minorTicks.append(i * 2000);	
  16. 	}
  17. }
  18.  
  19. mTimeScaleDiv.setTicks(QwtScaleDiv::MajorTick, majorTicks);
  20. mTimeScaleDiv.setTicks(QwtScaleDiv::MinorTick, minorTicks);
  21.  
  22. // This returns false - why?
  23. bool isValid = mTimeScaleDiv.isValid();
  24.  
  25. setAxisScaleDiv(QwtPlot::xBottom, mTimeScaleDiv);
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Could anyone help me with an explanation why the scale div I'm creating is set to invalid?