R/contr.effect.R

In gvcm.cat: Regularized Categorical Effects/Categorical Effect Modifiers/Continuous/Smooth Effects in GLMs

contr.effect <- function (n, contrasts = TRUE, sparse = FALSE) # => 1. category as reference, contr.sum => last category as reference
{
    if (length(n) <= 1L) {
        if (is.numeric(n) && length(n) == 1L && n > 1L)
            levels <- seq_len(n)
        else stop("not enough degrees of freedom to define contrasts")
    }
    else levels <- n
    cont <- diag(length(levels))
    if (contrasts) {
        cont <- cont[, -1, drop = FALSE]
        cont[1, ] <- -1
        colnames(cont) <- NULL
    }
    cont
}