Terms in formulae which are not syntactic names are not supported in R at
present, and nothing that I know of says they are. We are working towards
that as a goal, but this is not a bug.
On Wed, 27 Aug 2003 [EMAIL PROTECTED] wrote:
> Hi all,
> I've experienced this problem using step() and stepAIC() when a name of a
> regressors has blanks in between (R:R1.7.0, os: w2ksp4).
>
> Please look at the following code:
>
> "x" <-
> c(14.122739306734, 14.4831100207131, 14.5556459667089,
> 14.5777151911177,
> 14.5285815352327, 14.0217803203846, 14.0732571632964,
> 14.7801310180502,
> 14.7839362960477, 14.7862217992577)
>
> "reg" <-
> structure(list(feriale = c(0, 1, 1, 1, 1, 0, 0, 1, 1, 1),
> pasquetta = c(0,
> 0, 0, 0, 0, 0, 0, 0, 0, 0), giorno = structure(c(2, 3, 4, 5,
>
> 6, 7, 1, 2, 3, 4), class = "factor", .Label = c("1-DOM",
> "2-LUN",
> "3-MAR", "4-MER", "5-GIO", "6-VEN", "7-SAB"))), .Names =
> c("feriale",
> "pasquetta", "giorno"), row.names = c("1", "2", "3", "4",
> "5",
> "6", "7", "8", "9", "10"), class = "data.frame")
>
> #this works
> lm(x~., data=reg)
>
> #this works
> step(lm(x~., data=reg))
>
> #this works
> library(MASS)
> stepAIC(lm(x~., data=reg))
>
> #when you change a name of a regressors inserting blanks
> step and stepAIC won't work
> names(reg)[1]="with blank"
> names(reg)
>
> #this still works
> lm(x~., data=reg)
>
> #this doesn't work
> step(lm(x~., data=reg))
>
> #this is the error
> #"Error in parse(file, n, text, prompt) : parse error"
>
>
> #this doesn't work
> stepAIC(lm(x~., data=reg))
>
> # the error is the same as step
> #"Error in parse(file, n, text, prompt) : parse error"
>
>
> These are my R.version() and Sys.info() relevant infos.
> > R.Version()
> $platform
> [1] "i386-pc-mingw32"
>
> $arch
> [1] "i386"
>
> $os
> [1] "mingw32"
>
> $system
> [1] "i386, mingw32"
>
> $status
> [1] ""
>
> $major
> [1] "1"
>
> $minor
> [1] "7.0"
>
> $year
> [1] "2003"
>
> $month
> [1] "04"
>
> $day
> [1] "16"
>
> $language
> [1] "R"
>
> > Sys.info()
> sysname release
> version
> "Windows" "NT 5.0" "(build 2195)
> Service Pack 4"
> machine
> "x86"
>
> ______________________________________________
> [EMAIL PROTECTED] mailing list
> https://www.stat.math.ethz.ch/mailman/listinfo/r-devel
>
>
--
Brian D. Ripley, [EMAIL PROTECTED]
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)
Oxford OX1 3TG, UK Fax: +44 1865 272595
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