R help - Mar 2003 - help with likelihood contour plot

Can some kind person point out my error here? I'm trying to set up a 
grid for a countour plot of a likelihood function.

 > u <- rnorm(20,9.5,2.5)
 > # sample of size 20 from N(9.5,2.5^2)
 > loglik <- function(th1,th2) {
+ n <- length(u)
+ -(n/2)*log(2*pi*th2^2)-0.5*sum((u-th1)^2/th2^2)
+ }
 > x <- seq(4.5,14.5,len=50)
 > y <- seq(0.5,6,len=50)
 > f <- outer(x, y, loglik(x,y))
Error in match.fun(FUN) : not function, character, or symbol: "loglik(x,
y)"
In addition: Warning message:
longer object length
         is not a multiple of shorter object length in: u - th1
 > loglik(9,2)
[1] -44.56294
 > is.function(loglik)
[1] TRUE

Thanks,

Murray
-- 
Dr Murray Jorgensen      http://www.stats.waikato.ac.nz/Staff/maj.html
Department of Statistics, University of Waikato, Hamilton, New Zealand
Email: maj at waikato.ac.nz                                Fax 7 838 4155
Phone  +64 7 838 4773 wk    +64 7 849 6486 home    Mobile 021 1395 862

Murray Jorgensen wrote:
> Can some kind person point out my error here? I'm trying to set up a 
> grid for a countour plot of a likelihood function.
> 
>  > u <- rnorm(20,9.5,2.5)
>  > # sample of size 20 from N(9.5,2.5^2)
>  > loglik <- function(th1,th2) {
> + n <- length(u)
> + -(n/2)*log(2*pi*th2^2)-0.5*sum((u-th1)^2/th2^2)
> + }
>  > x <- seq(4.5,14.5,len=50)
>  > y <- seq(0.5,6,len=50)
>  > f <- outer(x, y, loglik(x,y))
> Error in match.fun(FUN) : not function, character, or symbol:
"loglik(x,
> y)"
> In addition: Warning message:
> longer object length
>         is not a multiple of shorter object length in: u - th1
>  > loglik(9,2)
> [1] -44.56294
>  > is.function(loglik)
> [1] TRUE
> 
> Thanks,
> 
> Murray

Murray,
   From ?outer:

Details:

      `FUN' must be a function (or the name of it) which expects at
      least two arguments and which operates elementwise on arrays.


Thus, use "loglik" and not "loglik(x,y)", as in:

outer(x,y,loglik)

Regards,
Sundar