[R] evir: generalized pareto dist

2006-06-05 Thread Werner Tell
Hi, I'm fitting a generalized Pareto distribution to POT exceedances of a data set. The practical stuff works ok, but I have a question regarding theory. Is there an equation relating parameters of a gpd tail to its (first) moments? According to theory for certain parameters either the first

[R] negative binomial: expected number of events?

2006-06-05 Thread Werner Tell
Hi I'm fitting poisson and negative binomial distributions to event data. I'm interested in the expected number of events occuring in a time period. For the poisson this is determined by the parameter lambda only. For the neg. binomial, is the expected number of events determined by the