[R] Problem with stepAIC, "invalid second argument"

[Prof Brian Ripley]

Try ?df to see what you did wrong!

Always use conflicts() before posting to see what you have overridden.
R normally allows you to get away with masking objects, but in this case 
it is the R object that is masking yours.


On Sun, 26 Dec 2004, Klaus Thul wrote:

> am I doing something wrong, or is this a bug (R 2.0.1 & 1.9.1,
> linux&windows):
>
>    > library(MASS)
>    > df <- data.frame(x = rnorm(100), y = rnorm(100), z = rnorm(100))
>    > f <- lm(x ~ y + z, data = df)
>    > stepAIC(f, scope = list(upper = ~y * z, lower = ~1))
>    Start:  AIC= -16.56
>     x ~ y + z
>    Error in eval(expr, envir, enclos) : invalid second argument

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
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