[R] R hang-up using lm

[Peter Dalgaard]

Göran Broström <gb at stat.umu.se> writes:

> > >    >> set.seed(3)
> > >    >> yy <- rnorm(20)
> > >    >> gg <- rep(1:10, 2)
> > >    >> y <- tapply(yy, gg, median)
> > >    >> x <- 1:10
> > >    >> z <- lm(y ~ x)  # OK
> > >    >> z <- lm(x ~ y)  # crashes R
....
> I had to try it too: No crashes on Win2000 pro (1.8.1) or Linux (1.9.0),
> but (in both cases):
> 
> 
> >  lm(y ~ x)
> 
> Call:
> lm(formula = y ~ x)
> 
> Coefficients:
> (Intercept)            x  
>     -0.8783       0.1293  
> 
> 
> >  lm(x ~ y)
> 
> Call:
> lm(formula = x ~ y)
> 
> Coefficients:
> (Intercept)  
>         5.5  
> 
> i.e., only an intercept estimate in the second case! Surely something is
> wrong!? 

I just tried it on the 64-bit system and got Göran's result. However,
repeating the lm(x~y) bit seems to have gotten itself stuck after the
3rd time (looks like a memory runaway problem, currently at 3.6GB and
counting...). So perhaps those who couldn't reproduce should try it with
replicate(100, lm(x~y)) or so.

-- 
   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