Hi,For discrete distribution like Poisson, think you can vectorize the
power/factorial bit, that should be much quicker.p:{exp[neg
x]*(prds["f"$i#x]j)%prds["f"$1+til i:max y]j:-1+y}p[1.5;1 2 3 4 5]For
large lambda (>50) you can use normal pdf with co...

need to transform your time series(s) to stationary processes.Then there
are a number of way to perform cross valuation specific for time series
data, one typical
uses:https://www.sciencedirect.com/science/article/pii/S0304407600000300RegardsXi