I am writing a macro that would use values from a Zemax-computed interferogram to optimize the lens system. 

I have came across the GETTEXTFILE ZPL command that allows one to specify the type of text file along with some settings that are specified with the MODIFYSETTINGS command. I found this syntax: 

GETTEXTFILE textfilename$, type, settingsfilename$, flag

for type, one could specify “wfm” for wavefront map or “int” for interferogram. 

One could specify the sampling resolution of either the wavefront map or the interferogram in the GUI. However, in ZPL, there is no way to specify the sampling resolution for interferograms. Whereas for wavefront map, one could use the WFM_SAMP argument.

Question: Is there a way to specify interferogram sampling resolution, similar to wavefront map?