R help - Nov 2006 - Calling an arbitrarily named data frame + variable

If I want to pass a data frame variable name and a specific component name
of the data frame to a function, and I want the function to operate on this
(e.g. Data frame = "data1" and the component in question is
"component1", so
I want the function to operate on data1$component1), how do I pass and call
this info?  This would be for an arbitrarily named data frame and component
name, e.g. The function should also be able to handle it if I pass data2 and
component2, e.g. function1 <- function(dataframename,componentname) {} ...
function1("data2","component2")

--j

-- 
Jonathan A. Greenberg, PhD
NRC Research Associate
NASA Ames Research Center
MS 242-4
Moffett Field, CA 94035-1000
Office: 650-604-5896
Cell: 415-794-5043
AIM: jgrn307
MSN: jgrn307 at hotmail.com

Try this:

f <- function(DF, vnam) {
  if (is.character(DF)) DF <- get(DF)
  head(DF[[vnam]])
}

f(iris, "Species")
f("iris", "Species")


On 11/1/06, Jonathan Greenberg <jgreenberg at arc.nasa.gov>
wrote:
> If I want to pass a data frame variable name and a specific component name
> of the data frame to a function, and I want the function to operate on this
> (e.g. Data frame = "data1" and the component in question is
"component1", so
> I want the function to operate on data1$component1), how do I pass and call
> this info?  This would be for an arbitrarily named data frame and component
> name, e.g. The function should also be able to handle it if I pass data2
and
> component2, e.g. function1 <- function(dataframename,componentname) {}
...
> function1("data2","component2")
>
> --j
>
> --
> Jonathan A. Greenberg, PhD
> NRC Research Associate
> NASA Ames Research Center
> MS 242-4
> Moffett Field, CA 94035-1000
> Office: 650-604-5896
> Cell: 415-794-5043
> AIM: jgrn307
> MSN: jgrn307 at hotmail.com
>
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