PerformanceAnalytics has long enjoyed contributions from users who would like to see specific functionality included. Diethelm Wuertz at ETHZ, who is the author and sponsor of all the various R/Metrics packages is one of those contributors. I first met Diethelm when he hosted a conference on high-frequency data in the early 1990′s (where we fretted 



![weird [lack of] control…](http://xianblog.files.wordpress.com/2012/02/dscn1921-e1329726991744.jpg?w=450&h=101)


Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).