[R] Question on deriv3()

[Mervyn G Marasinghe]

Hello:

Why is deriv3() functioning differently in R from that in Splus
using library(MASS) ? For example
deriv3(~(t1*log(t2)+lgamma(t1)+(1-t1)*log(y)+y/t2),c("t1","t2"),function(y,t1,t2)NULL)
complains of  lgamma.

Mervyn