Ok, please consider it as a bad call.
Thanks for your answers.
Best,
Mathieu
Prof Brian Ripley a écrit :
On Fri, 8 Aug 2008, Mathieu Ribatet wrote:
Dear list,
Here's a suggestion about the different optimization code. There are several
optimization procedures in the base package (optim, optimize, nlm, nlminb,
..). However, the output of these functions are slightly different. For
instance,
1. optim returns a list with arguments par (the estimates), value the
minimum (maxima) of the objective function, convergence (optim
.convergence)
2. optimize returns a list with arguments minimum (or maximum) giving
the estimates, objective the value of the obj. function
3. nlm returns a list with arguments minimum giving the minimum of
the obj. function, minimum the estimates, code the optim. convergence
4. nlminb returns a list with arguments par (the estimates),
objective, convergence (conv. code), evaluations
Furthermore, optim keeps the names of the parameters while nlm, nlminb don't.
s
I believe it would be nice if all these optimizers have a kind of homogenized
output. This will help in writing functions that can call different
optimizers. Obviously, we can write our own function that homogenized the
output after calling the optimizer, but I still believe this will be more
user-friendly.
Do you think this is a reasonable feature to implement - despite it isn't an
important point?
This would be essentially impossible without breaking most existing code,
and in the case of optimize() and nlminb() that goes back many years to
uses in S(-PLUS).
Best,
Mathieu
* BTW, if this is relevant, I could try to do it.
--
Institute of Mathematics
Ecole Polytechnique Fédérale de Lausanne
STAT-IMA-FSB-EPFL, Station 8
CH-1015 Lausanne Switzerland
http://stat.epfl.ch/
Tel: + 41 (0)21 693 7907
______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
--
Brian D. Ripley, [EMAIL PROTECTED]
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
--
Institute of Mathematics
Ecole Polytechnique Fédérale de Lausanne
STAT-IMA-FSB-EPFL, Station 8
CH-1015 Lausanne Switzerland
http://stat.epfl.ch/
Tel: + 41 (0)21 693 7907
______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
