Sorry, this should work
fun1 <- function(n){
vec1 <- LETTERS
if(n <=26){
res <- vec1[seq_len(n)]
}
else if(n>26 & n <=702){
res <- c(LETTERS,apply(expand.grid(vec1,vec1)[,2:1],1,paste,collapse=""))[1:n]
}
else if(n >702 & n <=18278){
res <-
c(LETTERS,apply(expand.grid(vec1,vec1)[,2:1],1,paste,collapse=""),apply(expand.grid(vec1,vec1,vec1)[,3:1],1,paste,collapse=""))[1:n]
}
else {
res <- NA
}
res
}
fun1(0)
character(0)
> fun1(8)
[1] "A" "B" "C" "D" "E" "F" "G" "H"
> fun1(40)
[1] "A" "B" "C" "D" "E" "F" "G" "H" "I" "J" "K" "L" "M" "N" "O"
[16] "P" "Q" "R" "S" "T" "U" "V" "W" "X" "Y" "Z" "AA" "AB" "AC" "AD"
[31] "AE" "AF" "AG" "AH" "AI" "AJ" "AK" "AL" "AM" "AN"
> fun1(18279)
[1] NA
A.K.
On Monday, January 27, 2014 5:11 PM, Dustin Fife <fife.dus...@gmail.com> wrote:
There seems to be a problem with that function: object 'vec1' not found.
On Mon, Jan 27, 2014 at 4:05 PM, arun <smartpink...@yahoo.com> wrote:
>
>
> HI,
>
> May be you can try:
>
> fun1 <- function(n){
> if(n <=26){
> res <- LETTERS[seq_len(n)]
> }
> else if(n>26 & n <=702){
> res <-
> c(LETTERS,apply(expand.grid(vec1,vec1)[,2:1],1,paste,collapse=""))[1:n]
> }
> else if(n >702 & n <=18278){
> res <-
> c(LETTERS,apply(expand.grid(vec1,vec1)[,2:1],1,paste,collapse=""),apply(expand.grid(vec1,vec1,vec1)[,3:1],1,paste,collapse=""))[1:n]
> }
> else {
> NA
> }
> res
> }
> fun1(0)
> #character(0)
> fun1(2)
> #[1] "A" "B"
>
> fun1(28)
> A.K.
>
>
>
>
> On Monday, January 27, 2014 4:41 PM, Dustin Fife <fife.dus...@gmail.com>
> wrote:
> Hi all,
>
> I frequently get requests to do data analysis where the person
> references an excel column. e.g., "I want to analyze [insert complex
> variable name], located at column AAQ in Excel." I've been doing is
> gsub and inserting a part of the string for the complex variable name,
> then going from there. But, I was trying to make function that returns
> the following vector:
>
> excelVector = A, B, C, D,...AA, AB, AC...ZA, ZB, ZC,...AAA, AAB, AAC, etc.
>
> In other words, the argument would have one argument (n, or the number
> of columns), then it would return a list like that shown above. Then,
> all I would have to do is
>
> column.of.interest = which(excelVector=="AAQ")
>
> But I'm a bit stumped. The first part is easy:
>
> LETTERS[1:26]
>
> The next would probably use expand.grid, but all my potential
> solutions are pretty clunky.
>
> Any ideas?
>
> ______________________________________________
> R-help@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.
>
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