In reply to Ksharp.

Thanks for this contribution. I like that you always try new variations and share your ideas. In this case, you need to use the same OFFSETMIN= and OFFSETMAX= options in the XAXIS and XAXIS2 statements so that the vertical grids align. You might also want to reduce the size of the axis values by using VALUEATTRS=(size=6).

I will point out that the axis table approach can handle more than two variables, whereas overloading the XAXIS and XAXIS2 tick values is limited to at most two variables.