[R] Simple question on eval

[Joshua Wiley]

Hi Kel,

Try this:

eval(parse(text = a))
x

Many times (though certainly not all), it may be easier/cleaner to
rethink what you are doing (the step before you get a <- "x <- 2^2")
to see if there is a simpler way.

Cheers,

Josh

On Tue, Nov 30, 2010 at 2:24 PM, Lamke <lamkelf at gmail.com> wrote:
>
> Hi group,
>
> I did some searches about this very simple question.  Hope someone can help
> me out.
>
> If I have the following:
>
> a <- "x <- 2^2"
> a
> [1] "x <- 2^2"
>
> How do I evaluate the expression that gets me an answer of 4?  I tried the
> following:
>
>> eval(a)
> [1] "x <- 2^2"
>> get(a)
> Error in get(a) : object 'x <- 2^2' not found (apparently it's not right!!)
>
> I have one long string of commands separated by semi-colon and hope to sort
> it out.  Thank you so much!!!
>
> Kel
> --
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>
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>



-- 
Joshua Wiley
Ph.D. Student, Health Psychology
University of California, Los Angeles
http://www.joshuawiley.com/