[R] Question about expand.grid function in R

[peter dalgaard]

On May 1, 2012, at 15:36 , R. Michael Weylandt wrote:

> I don't think you can do it within expand.grid() but something like
> this might work:
> 
> rownames(x) <- apply(x, 1, paste, collapse = "")
> 

Also

rownames(x) <- do.call(paste, c(x, sep=""))

or, in recent versions,

rownames(x) <- do.call(paste0, x)

> Michael
> 
> On Tue, May 1, 2012 at 5:05 AM, Kelly Cool <kellycool79 at yahoo.com> wrote:
>> Hi,
>> 
>> I am extremely new to R, and was wondering if someone would be able to help me with a question regarding the expand.grid function. When I input
>> 
>> expand.grid.rep <- function(x, n=1) do.call(expand.grid, rep(list(x),n))
>> expand.grid.rep(c("a", "b", "c"), 3)
>> 
>> my output is as follows,
>> 
>> Var1 Var2 Var3
>> 1     a    a    a
>> 2     b    a    a
>> 3     c    a    a
>> 4     a    b    a
>> 5     b    b    a
>> 6     c    b    a
>> 7     a    c    a
>> 8     b    c    a
>> 9     c    c    a
>> 10    a    a    b
>> 11    b    a    b
>> 12    c    a    b
>> 13    a    b    b
>> 14    b    b    b
>> 15    c    b    b
>> 16    a    c    b
>> 17    b    c    b
>> 18    c    c    b
>> 19    a    a    c
>> 20    b    a    c
>> 21    c    a    c
>> 22    a    b    c
>> 23    b    b    c
>> 24    c    b    c
>> 25    a    c    c
>> 26    b    c    c
>> 27    c    c    c
>> 
>> I was wondering if there was anyway I can change the row numbers to labels that indicate what is in each row. Instead of a 1, I'd like to have a label saying "aaa", etc. I'm not sure if this is even possible within the expand.grid function but any help would be appreciated. Thanks.
>>        [[alternative HTML version deleted]]
>> 
>> 
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>> and provide commented, minimal, self-contained, reproducible code.
>> 
> 
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

-- 
Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com