Set variable names from superheat funciton

[KarlFetter]

Hello,
I'm trying to change the row names of my variables on the left and bottom axes. I know I can do this by changing the names in the input data.frame, but some of my variables require an expression(paste()) command to work in greek letters and superscripts.

Is there a method for doing this? I see there is a function, generate_var_label(), but it's use doesn't appear to be documented any where and I can't get it to work.

Thanks for the great package, very useful and straightforward.