From ligges at statistik.tu-dortmund.de  Thu Mar  5 12:15:37 2009
From: ligges at statistik.tu-dortmund.de (ligges at statistik.tu-dortmund.de)
Date: Thu,  5 Mar 2009 12:15:37 +0100 (CET)
Subject: [Rd] bug (PR#13570)
Message-ID: <20090305111537.12F232832198@mail.pubhealth.ku.dk>

Berwin A Turlach wrote:
> G'day Peter,
> 
> On Thu, 05 Mar 2009 09:09:27 +0100
> Peter Dalgaard <p.dalgaard at biostat.ku.dk> wrote:
> 
>> rhafen at 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 at 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



[Rd] bug (PR#13570)
ligges at statistik.tu-dortmund.de