[R] function - access column

[Ana]

Thanks! It helps. I completely forgot about the colnames function

I added a "which(colnames(m)==n)" to my own function and now I can
access with no problem the column by the number instead of the name.




On Fri, Oct 7, 2011 at 5:09 PM, R. Michael Weylandt
<michael.weylandt at gmail.com> <michael.weylandt at gmail.com> wrote:
> Perhaps something like this:
>
> Test <- function(m){
>     m <- if(is.character(m)) get(m) else m
>     stopifnot(length(colnames(m))>0)
>     n = colnames(m)
>     # Process n however
>     2* m[, n]
> }
>
> That make sense?
>
> Hope it helps,
> Michael
>
>
> On Oct 7, 2011, at 11:03 AM, Ana <rrasterr at gmail.com> wrote:
>
>> How can I call matrix$col, inside a function?
>> The matrix name is one of the variables of the function, while the
>> column name I get by assuming that it should have a certain
>> characters.
>>
>> something like this
>>
>> function(matrix){
>> colname=as.name(grep("[A-T a-t]ting",colnames(matrix),value=TRUE))
>> output=2*(matrix$colname)
>> return(output)
>> }
>>
>> The name of the column is Testing.
>>
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>