R help - May 2004 - Problem with logtrans, from library MASS

Greetings all!

This problem occurs using R 1.8.1 on Windows XP. I downloaded the 
binaries for R and all packages, including the VR bundle, in December 2003.

The data consists of NZ$ prices and attributes for 643 cars.

 > summary(price)
    Min. 1st Qu.  Median    Mean 3rd Qu.    Max.    NA's
   14290   35800   48990   65400   79000  285000       2
 > library(MASS)
 > boxcox(price ~ doors+CC+KW+KG+LENGTH, lambda=seq(-0.1,0.5,length=30))
 > boxcox(price ~ doors+CC+KW+KG+LENGTH, lambda=seq(-0.5,0.1,length=30))

This all works fine, I get a fairly sharp peak near lambda=-0.25, but then:

 > logtrans(price ~ doors+CC+KW+KG+LENGTH, alpha=seq(-10000,0,length=30))
Error in eval(expr, envir, enclos) : Object "price" not found


Comments welcome,

Murray
-- 
Dr Murray Jorgensen      http://www.stats.waikato.ac.nz/Staff/maj.html
Department of Statistics, University of Waikato, Hamilton, New Zealand
Email: maj at waikato.ac.nz                                Fax 7 838 4155
Phone  +64 7 838 4773 wk    +64 7 849 6486 home    Mobile 021 1395 862

Murray Jorgensen <maj at stats.waikato.ac.nz> writes:
> Greetings all!
> 
> This problem occurs using R 1.8.1 on Windows XP. I downloaded the
> binaries for R and all packages, including the VR bundle, in December
> 2003.
> 
> The data consists of NZ$ prices and attributes for 643 cars.
> 
>  > summary(price)
>     Min. 1st Qu.  Median    Mean 3rd Qu.    Max.    NA's
>    14290   35800   48990   65400   79000  285000       2
>  > library(MASS)
>  > boxcox(price ~ doors+CC+KW+KG+LENGTH, lambda=seq(-0.1,0.5,length=30))
>  > boxcox(price ~ doors+CC+KW+KG+LENGTH, lambda=seq(-0.5,0.1,length=30))
> 
> This all works fine, I get a fairly sharp peak near lambda=-0.25, but then:
> 
>  > logtrans(price ~ doors+CC+KW+KG+LENGTH,
alpha=seq(-10000,0,length=30))
> Error in eval(expr, envir, enclos) : Object "price" not found
> 
The issue is that logtrans has a 'data' argument that defaults to NULL
(the author(s) may have a reason for having this inconsistent with
boxplot?). Adding data=.GlobalEnv seems to work.

-- 
   O__  ---- Peter Dalgaard             Blegdamsvej 3  
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