Message-ID: <49F8BD05.1070003@statistik.tu-dortmund.de>
Date: 2009-04-29T20:48:05Z
From: Uwe Ligges
Subject: Evaluation of an expression as function argument
In-Reply-To: <49F89CBF.5010102@cognigencorp.com>
Sebastien Bihorel wrote:
> Dear R-users,
>
> I would like to know if is it possible to set a function argument as an
> evaluated expression. I have tried several syntaxes, including the
> following example, but could not get it anything to run. The plot
> function is used here but I would like to later apply the same approach
> to other functions.
>
> ##########################
> items <- c(expression(col=2),expression(pch=2))
>
> for (in in seq(2)) {
> plot(1:10, eval(items[i]))
> }
> ##########################
Way 1:
for(i in seq(2))
do.call("plot", c(list(1:10), as.list(items[i])))
Way 2 is perhaps easier for you:
items <- list(col=2, pch=2)
for (i in seq(2))
do.call("plot", c(list(1:10), items[i]))
Ways 3...n up to others...
Uwe Ligges
>
> Thanks in advance for your input.
>
> Sebastien
>
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