R/cond.table.R

In davidavdav/ROC: Compute structures to compute ROC and DET plots and metrics for 2-class classifiers.

`cond.table` <-
function(x, cond, target=F) {
    x <- as.cst(x)
    if (!missing(cond)) {
        l <- eval(substitute(cond),x, parent.frame())
        nl <- as.list(1:ncol(x))
        names(nl) <- names(x)
        if (target) {                       # I am sure this can be done better
            t <- as.data.frame(table(data.frame(l,x$target)))
            names(t)[ncol(t)-1] <- "target"
            nf <- ncol(t)-2
        } else {
            t <- as.data.frame(table(l))
            nf <- ncol(t)-1
        }
        names(t)[1:nf] <- c(names(nl)[unlist(eval(substitute(cond), nl))])
    }
    t <- t[t$Freq>0,]
    class(t) <- c("cond.table", class(t))
    t
}