[R] forcing a zero level in contr.sum

[Gabor Grothendieck]

On Wed, Jul 7, 2010 at 10:55 PM, Charles C. Berry <cberry at tajo.ucsd.edu> wrote:
>
>
> contr.mysum <- function (n, contrasts = TRUE, sparse = FALSE,
> base=length(levels))
> {

The memisc package has a contr.sum function with a base= argument.