From murdoch at stats.uwo.ca  Thu Mar  5 12:56:45 2009
From: murdoch at stats.uwo.ca (Duncan Murdoch)
Date: Thu, 05 Mar 2009 06:56:45 -0500
Subject: [Rd] bug (PR#13570)
In-Reply-To: <49AFB412.2060807@statistik.tu-dortmund.de>
References: <20090304211010.A588D2832180@mail.pubhealth.ku.dk>	<49AF88B7.1000002@biostat.ku.dk>	<20090305174301.20099b11@berwin-nus1>
	<49AFB412.2060807@statistik.tu-dortmund.de>
Message-ID: <49AFBDFD.5000001@stats.uwo.ca>

Uwe Ligges wrote:
> 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.

I still see it in R-patched (haven't tried R-devel yet).  So I think it 
is worth tracking down and fixing; I'll do it later today.

Duncan Murdoch



[Rd] bug (PR#13570)
Duncan Murdoch