Example:
vgendesign -in design1.txt -out design1.v -tr 2 -ntimesteps 648 -deriv 1
vgendesign -in design2.txt -out design2.v -tr 2 -ntimesteps 648 -deriv 1
vcatdesign -in design1.v design2.v -out design.v
This sequence of program calls first generates two design matrices from two text files containing design specifications of two sessions. These two design matrices are then concatenated by 'vcatdesign' to allow for a fixed effects analysis across sessions.