Jacques Wagnor
2007-Jun-06 13:42 UTC
[R] A question about riskmeasures() vs. qgpd() in library(evir)
Dear List, This inquiry probably does not directly pertain to R. I am using library(evir) to learn EVT. Based on my reading of things, it is my understanding that if one wants to calculate quantiles of GPD, one could use either riskmeasures() or qgpd(). However, using data(danish) as an example, the quantile estimates produced by riskmeasures() are considerably different from those produced by qgpd() as follows:> library(evir) > data(danish) > out <- gpd(danish, 10) > riskmeasures(out, c(0.999, 0.9999))p quantile sfall [1,] 0.9990 94.28956 191.3697 [2,] 0.9999 304.62448 609.3696> qgpd(c(0.999, 0.9999), out$par.ests["xi"], out$par.ests["beta"])[1] 67.22493 200.41271 Any insights would be greatly appreciated. Regards, Jacques platform i386-pc-mingw32 arch i386 os mingw32 system i386, mingw32 status major 2 minor 5.0 year 2007 month 04 day 23 svn rev 41293 language R version.string R version 2.5.0 (2007-04-23)