R help - Jun 2010 - Column name defined by function variable

Hi all,

probably a simple problem for you but I am stuck.

This simple function adds columns (with differing length) to data frames:

add.col <- function(df, new.col) {
	n.row <- dim(df)[1]
	length(new.col) <- n.row
	cbind(df, new.col)
}

Now I would like to extend that method. A new parameter 'name' shouild
allow people to pass in a name for that new column. Is that possible
and how can this be achieved?

Example:

myData <- data.frame(c(1,2,3))
add.col(myData, c(5,6,7,8), 'more stuff')

adds a new column named 'more stuff' to the dataframe myData.


Any ideas?

Best,
Ralf

Hi,

I haven't check much of what you wrote, so just a blind guess. What 
about in the function's body before cbind():
names(new.col) <- "more stuff"
?

HTH,
Ivan

Le 6/17/2010 11:09, Ralf B a ?crit :
> Hi all,
>
> probably a simple problem for you but I am stuck.
>
> This simple function adds columns (with differing length) to data frames:
>
> add.col<- function(df, new.col) {
> 	n.row<- dim(df)[1]
> 	length(new.col)<- n.row
> 	cbind(df, new.col)
> }
>
> Now I would like to extend that method. A new parameter 'name'
shouild
> allow people to pass in a name for that new column. Is that possible
> and how can this be achieved?
>
> Example:
>
> myData<- data.frame(c(1,2,3))
> add.col(myData, c(5,6,7,8), 'more stuff')
>
> adds a new column named 'more stuff' to the dataframe myData.
>
>
> Any ideas?
>
> Best,
> Ralf
>
> ______________________________________________
> R-help at r-project.org mailing list
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> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
>    
-- 
Ivan CALANDRA
PhD Student
University of Hamburg
Biozentrum Grindel und Zoologisches Museum
Abt. S?ugetiere
Martin-Luther-King-Platz 3
D-20146 Hamburg, GERMANY
+49(0)40 42838 6231
ivan.calandra at uni-hamburg.de

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