Have you tried wrapping it in a function and using integrate()? R is pretty good at handling numerical integration. If integrate() isn't good for you, can you say more as to why?
Michael On Nov 6, 2011, at 4:15 PM, JeffND <zuofeng.shan...@nd.edu> wrote: > Hello to all, > > I am having trouble with intregrating a complicated uni-dimensional function > of the following form > > Phi(x-a_1)*Phi(x-a_2)*...*Phi(x-a_{n-1})*phi(x-a_n). > > Here n is about 5000, Phi is the cumulative distribution function of > standard normal, > phi is the density function of standard normal, and x ranges over > (-infty,infty). > > My idea is to to use quadrature to handle this integral. But since Phi has > not cloaed form, > I don't know how to do this effeciently. I appreciate very much if someone > has any ideas about it. > > Thanks! > > Jeff > > -- > View this message in context: > http://r.789695.n4.nabble.com/how-to-use-quadrature-to-integrate-some-complicated-functions-tp3996765p3996765.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.