[Rd] update.formula and backticked colons

Sundar Dorai-Raj sdorairaj at gmail.com
Thu Jul 30 23:30:27 CEST 2009

On Thu, Jul 30, 2009 at 2:28 PM, Sundar Dorai-Raj<sdorairaj at gmail.com> wrote:
> I just noticed the following in update.formula and I'm wondering if
> this behavior is the intention of the developers. Here's an example:
> update(`a: b` ~ x, ~ . + y)
> Note now that the response has no backticks and is interpreted as a:b
> (i.e. ":" is now an operator). This is because in update.formula the
> call to terms.formula uses simplify = TRUE. I'm working with data that
> has a lot of colons in their names and for reporting purposes I don't
> want to use make.names to avoid this situation. I do have a solution
> which simply avoids using update.formula, but I wonder if the
> developers would consider removing the "simplify" argument and allow
> it to be passed through "...", which is currently ignored by
> update.formula. Alternatively, add a simplify=TRUE to the
> update.formula call, which can manually be set to FALSE by the user.
> I would love to hear any comments or criticisms of my findings.
> Thanks,
> --sundar

Forgot my version info

> version
platform       x86_64-unknown-linux-gnu
arch           x86_64
os             linux-gnu
system         x86_64, linux-gnu
major          2
minor          9.1
year           2009
month          06
day            26
svn rev        48839
language       R
version.string R version 2.9.1 (2009-06-26)

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