[R] Thanks!

[Marc Schwartz]

on 07/03/2008 10:35 AM R_Learner wrote:
> Thanks guys!
> I think [[ seems to be the easier way, but I also spent an hour (while my
> post was pending approval) to find that the following also works:
> 
> temp<- eval(parse(text=paste("data$column_title"")))

To quote Thomas:

 > fortune("parse()")

If the answer is parse() you should usually rethink the question.
    -- Thomas Lumley
       R-help (February 2005)

:-)

In general, you should look at other means such as using assign() or 
get(), which in this case could be something like:

MyCol <- "Sepal.Length"

 > with(iris, get(MyCol))
   [1] 5.1 4.9 4.7 4.6 5.0 5.4 4.6 5.0 4.4 4.9 5.4 4.8 4.8 4.3 5.8 5.7
  [17] 5.4 5.1 5.7 5.1 5.4 5.1 4.6 5.1 4.8 5.0 5.0 5.2 5.2 4.7 4.8 5.4
...

See ?assign, ?get and ?with


To further quote "Yoda":

 > fortune("Yoda")

Evelyn Hall: I would like to know how (if) I can extract some of the
information from the summary of my nlme.
Simon Blomberg: This is R. There is no if. Only how.
    -- Evelyn Hall and Simon 'Yoda' Blomberg
       R-help (April 2005)


Regards,

Marc