[Rd] Name length of function argument? (PR#10357)

deiwiks at icr.gess.ethz.ch deiwiks at icr.gess.ethz.ch
Fri Oct 19 18:05:09 CEST 2007

I've just been programming a function to calculate the likelihood in a 
probit model.
The function looks like this

likelihood <- function(Y,X,p) {
Z <- p[1] +p[2]*X
P <- Y*pnorm(Z) + (1-Y)*(1-pnorm(Z))

out <- optim(likelihood,p=c(0,0),Y=wells$switch,X=wells$dist, hessian=TRUE)

X and Y are vectors containing column data.
This works fine, however, if I rename p to pp or anything that is longer 
than one character, I get the following error message:

Error in optim(f, pp = c(0, 0), Y=wells$switch, X=wells$dist, 
hessian=TRUE) :
  cannot coerce type closure to double vector

This seems like a bug... Or can you help me find the mistake I made?


Christa Deiwiks
International Conflict Research
ETH Zurich

Seilergraben 49 (SEI E.3)
8092 Zurich
Ph: +41 44 632 67 60


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