[R] Dataframe with single level column

[Blanchette, Marco]

Dear all,

I have a dataframe with multiple observations and the levels as the last column, as in:
d <- data.frame(A=sample(1:100,12),B=sample(1:100,12),levels=c(rep('A',4),rep('B',4),rep('C',4)))
> d
    A  B levels
1  77 40      A
2  14 18      A
3  56  7      A
4  46 27      A
5  63 35      B
6  80 21      B
7   3 54      B
8  93 76      B
9   5 46      C
10 16 53      C
11 40 17      C
12 25 31      C

I need to run anova analyis on the group in levels against the merge data in the first two columns. I can manually split and join the different columns as in

> d.t <- rbind(data.frame(value=d[,1],ind=d[,3]),data.frame(value=d[,2],ind=d[,3]))

but I was wondering if there would be a more elegant and easy way than that that would prevent me from hard coding the different vectors making the data frame.

Thanks

--
Marco Blanchette, Ph.D.
Assistant Investigator
Stowers Institute for Medical Research
1000 East 50th St.

Kansas City, MO 64110

Tel: 816-926-4071
Cell: 816-726-8419
Fax: 816-926-2018