Opening of usable functions in SeriesAggreg
"min", "max" and "median" should be usable besides "sum" and "mean" functions currently available in SeriesAggreg. But also other functions as below:
A call to a function named "qn" should be interpreted as
quantile(x, probs = n) (i.e. "q90" as
probs = 0.9)
Any function taking a vector as first argument and returning a single value.