[R] loess crash

[Peter Dalgaard BSA]

John Deke <jdeke2 at comcast.net> writes:

> Hmm... if I reduce the number of observations to just 500, I still get
> the error.
> 
> I don't think its an issue of colinearity, because I've tried several
> different combinations of variables, all of which work just fine in an
> OLS or logistic regression.
> 
> I'm probably doing something stupid, but I'm not seeing it...
> 
> At 02:00 PM 9/15/2002, John Deke wrote:
> >Hi,
> >
> > I have a data frame with 6563 observations. I can run a regression
> > with loess using four explanatory variables. If I add a fifth, R
> > crashes. There are no missings in the data, and if I run a
> > regression with any four of the five explanatory variables, it
> > works. Its only when I go from four to five that it crashes.

Hmm... I wouldn't try loess with more than one or two descriptors. I
mean, it's a smoothing method and representing a smooth function of
many variables can be computationally demanding.

The Fortran source code for loess is one of the more obfuscated pieces
of R, but I can see that some structures inside of it are of fixed
size, which might explain it (BTW: Does R really crash, or just say
memory exhausted?).

Do you have a simple example that reproduces the crash (using random
numbers, e.g.)?

-- 
   O__  ---- Peter Dalgaard             Blegdamsvej 3  
  c/ /'_ --- Dept. of Biostatistics     2200 Cph. N   
 (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)             FAX: (+45) 35327907
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