On Wed, 23 Jun 2004 Kang.Changku at epamail.epa.gov wrote:
> Dear, R experts.
> Does anybody have experience with 'optim' function?
Yes.
> I have an error message as the following.
>
> Error in optim(transcoefs, fn = hfdeviance, gr = hfdeviance.grad, method
> = "BFGS", :
> initial value in vmmin is not finite
>
> I want to make a comment when this happen.
Function 'fn' can return 'NA' or 'Inf' if the
function cannot be
evaluated at the supplied value, but the initial value must have a
computable finite value of 'fn'. (Except for method
'"L-BFGS-B"'
where the values should always be finite.)
It's your error so you can control it (by not making the error).
> Is there way I can put *my* message after this error occur?
You can use try/tryCatch and similar constructs. But it would be better
to use a valid starting value as optim asks, and you can so that by
calling hfdeviance(transcoefs) and checking it is finite.
--
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 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595