Berwin A Turlach wrote:
G'day Peter,

On Thu, 05 Mar 2009 09:09:27 +0100
Peter Dalgaard <p.dalga...@biostat.ku.dk> wrote:

rha...@stat.purdue.edu wrote:
<<insert bug report here>>

This is a CRITICAL bug!!!  I have verified it in R 2.8.1 for mac
and for windows.  The problem is with loess degree=0 smoothing.
For example, try the following:

x <- 1:100
y <- rnorm(100)
plot(x, y)
lines(predict(loess(y ~ x, degree=0, span=0.5)))

This is obviously wrong.
Obvious? How? I don't see anything particularly odd (on Linux).

Neither did I on linux; but the OP mentioned mac and windows.
On windows, on running that code, the lines() command added a lot of
vertical lines; most spanning the complete window but some only part.
Executing the code a second time (or in steps) gave sensible
results.
My guess would be that some memory is not correctly allocated or
initialised.  Or is it something like an object with storage mode
"integer" being passed to a double?  But then, why doesn't it show on
linux?

Happy bug hunting.  If my guess is correct, then I have no idea how to
track down such things under windows.....

Cheers,

        Berwin

______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel


Please can you folks try under R-devel (to be R-2.9.0 in a couple of weeks) and report if you still see it. I do not under R-devel (but do under R-release), so my guess is that something called by loess() has been fixed in the meantime.

Moreover it is not the plot stuff that was wrong under R-2.8.1 (release) but the loess computations.

Uwe Ligges

______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel

Reply via email to