Hi, I'm writing a function f() which includes probability density function computation, I would like to make this generic, that is , I will specify the density when I call f(), here's what I wrote: do.call(den, args=list(d, arg)) the question is , say, if I let den=dnorm, I have to replace arg with mean=??, sd=??, etc. but I tried arg=c(mean=..,sd=..) and arg="mean=..,sd=..", neither of these worked. What is the right way to do this ? Thanks a lot tong