R devel - Aug 2000 - predict.lm is broken in 1.1.0-patched (2000-August-7) (PR#627)

On 7 Aug 2000, Peter Dalgaard BSA wrote:
> ripley@stats.ox.ac.uk writes:
> 
> > predict.lm has been broken by recent changes to the patched branch.
> > 
> > It fails for all singular fits.  An example:
<snip>
> Sometimes the fix for one bug uncovers another. We have
> 
> > coef.aov
> function (object, ...) 
> {
>     z <- object$coef
>     z[!is.na(z)]
> }
> > coef.lm 
> function (object, ...) 
> object$coefficients
Ok, this explains it.  I *did* test it with a singular fit, but only with
lm(), not with aov().

coef.lm seems a more sensible convention, since it's a lot easy to remove
the NAs than to add them.


	-thomas



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thomas@biostat.washington.edu writes:
> > > coef.aov
> > function (object, ...) 
> > {
> >     z <- object$coef
> >     z[!is.na(z)]
> > }
> > > coef.lm 
> > function (object, ...) 
> > object$coefficients
> 
> Ok, this explains it.  I *did* test it with a singular fit, but only with
> lm(), not with aov().
> 
> coef.lm seems a more sensible convention, since it's a lot easy to
remove
> the NAs than to add them.
I've committed a fix for predict.lm to use object$coefficients
directly, but I haven't done anything with the coef() methods.

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