Re: [R] display of a loess fitted surface

From: Prof Brian Ripley <ripley_at_stats.ox.ac.uk>
Date: Fri 19 Aug 2005 - 01:59:57 EST

On Thu, 18 Aug 2005, Marta Colombo wrote:

> I am Marta Colombo,student at Politecnico,Milan. I am studying local
> regression models and I am using loess function. My problem is that when
> I have a loess object I don't know how to display the fitted surface; in
> fact, while in S when you have a loess object you can see it writing
> plot(object), in R this dosen't work.

Why not use S if that does what you want?

There are examples using R in MASS, for example: see the ch04.R and ch15.R scripts.

> Also I'd like to know if there is something like the S function
> pointwise that computes upper and lower confidence intervals.

(Do you mean upper and lower confidence limits?)

Thats a more general question. Many of R's predict() methods can construct confidence (and tolerance) intervals. If not, it is easy to do this yourself, as pred_obj$fit-/+pred_obj$se*qnorm(alpha/2).

-- 
Brian D. Ripley,                  ripley@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

______________________________________________
R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
Received on Fri Aug 19 02:04:39 2005

This archive was generated by hypermail 2.1.8 : Sun 23 Oct 2005 - 15:30:20 EST