[R] display of a loess fitted surface

[Prof Brian Ripley]

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 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)
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