[R] Escape sequence in eval ()

[Uwe Ligges]

On 15.06.2011 15:58, Franc Lucas wrote:
>
>     Hello,
>     I am wondering how to get the quotation marks into a variable expression. I
>     can't escape it with the backslash \ ...
>     Example:
>     I can access my data frame via
>     TABLE$"2011-01-02"$columnD
>     Now I want to do this automatically.. (with a for loop)..

Use the form

TABLE[["2011-01-02"]][["columnD"]]

and you can easily replace:

>     a<- TABLE
>     b<- " \"2011-01-02\" "

use simply

b <- "2011-01-02"


>     c<- "columnD"

Now forget the nonsense below and just do:
TABLE[[b]][[c]]

Uwe Ligges


>     acessmytable<- paste(a,b,c, sep="$")
>     parse(text="accessmytable")
>     eval(accessmytable)
>     It will return
>     [1] "TABLE$\"2011-01-02\"$close"
>     but I need
>     TABLE$"2011-01-02"$close
>     I highly appreciate your help!
>     Sincerely,
>     Franc
>     BS Student, University of Mannheim
>
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>
> References
>
>     1. http://produkte.web.de/go/toolbar
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