GFST returns an aggregate first statistics for an input variable.
The number of values that are aggregated is determined based on the frequency of the input variable.
Cx is a input conditional variable x.
The input variable frequency should be less than the result variable frequency. It makes sense to aggregate 5 one-minutely values into a 1 five-minute variable, but not the other way around.
V6081 = GFST(C6000)
where V6000 is a 15 minute variable, and V6081 is an hourly variable.