[R] passing parameters in optim()

[Prof Brian Ripley]

On Tue, 5 Feb 2002, Nancy Lo wrote:

> Hi all,
>
> I am using optim() to get estimate for parameter 'a' which will minimize
> the output of lprob.catch(a) and I got an error message:
>
> > optim(2,lprob.catch(x, freq,1, 0.5,0.5, a,- 0.7, 1, -0.7,0.1,
> 1,0.2,2,1,data.sf.mont))
> Error in catch2.fun(k, f1, f2, a, b, A, B, R, n0, av, index.n) :
>         Object "a" not found
>
>
> Why wasn't the initial value of a=2 passed to catch2.fun() which was
> called by lprob.catch()?

>From ?optim

      fn: A function to be minimized (or maximized), with first
          argument the vector of parameters over which minimization is
          to take place. It should return a scalar result.

and a is not the first argument: you told it to optimze over x.

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272860 (secr)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595

-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
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
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._