Dear Freesurfer gurus, 

I am trying to create an FSDG file for my data set and I have a question regarding discrete variables. 

So say this is my data: Two discrete variables (two with two levels, one with eight), one continuous variable.

I'm interested in one discrete variable (Patient/Control) with two levels and want to account for the effect of the others in the analysis. 

How should I construct my FSDG file? Can I have three columns for discrete variables (1) or should I have one column (2)? Or is there another way?

(1) So should I do:
GroupDescriptorFile 1

Title GroupAnalysis

Class Male

Class Female

Class Patient

Class Control

Class ImagingsiteOne

Class ImagingsiteTwo

[and so on...]

Class OccupationEight

Variables        Age   

Subject1    Male    Patient    ImagingsiteThree    16

Subject2    Male    Control    ImagingsiteSeven    18

Subject3    Female    Patient    ImagingsiteThree    23

And so on

OR 

(2) Should I do 

GroupDescriptorFile 1

Title GroupAnalysis

Class MalePatientImagingsiteOne

Class MalePatient​ImagingsiteTwo

[and so on..]

Class MalePatient​ImagingsiteEight

Class MaleControlImagingsiteOne

[and so on...]

Class FemalePatient​ImagingsiteOne

[and so on until...]

Class FemaleControl​ImagingsiteEight

Variables        Age   

Subject1    MalePatientImagingsiteThree    16

Subject2    MaleControlImagingsiteSeven    18

Subject3    FemalePatientImagingsiteThree    ​23

And so on

Thank you!

Best wishes, 

Hanna