[R] None of pweibull/dweibull in the derivatives table?

C. Joseph Lu cjlu at ibm.stat.ncku.edu.tw
Sat Jan 20 14:42:19 CET 2001

Dear friends in R-world,

It seems like there is none of pweibull/dweibull (and other distribution
available in the derivatives table.

What I want to do is to feed both gradient and hessian into nlm()
on calculating MLE of Weibull distribution (with censored data),
however, I just can't get gradient by deriv() in R
(not even bother to mention hessian).

In Venables & Ripley's MASS book, this was (mine is 2nd ed., sorry)
discussed with deriv3(), however,
the formation of deriv3 differs from R's deriv.

Best regards,

C. Joseph Lu
Department of Statistics
National Cheng-Kung University
Tainan, Taiwan

r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-help-request at stat.math.ethz.ch

More information about the R-help mailing list