Different or variable intervals on Flex chart axis

I have a Flex chart and on the x-axis want to be able to have different intervals set so I can draw gridlines.

For example the axis may be from 0 to 82 and I would want to have an interval at开发者_开发问答 6,8, 21, 29, 40, 49, 52, 59 and 70.

I believe what you're looking for are AxisRenderers, more specifically, the LinearAxis object. However, since your intervals have a weird separation, you might have to extend the class to add your own code.