margin <- function(rf, observed) {    if( !inherits(rf, "randomForest") ) {        stop("margin defined for Random Forests")    }    if( is.null(rf$votes) ) {        stop("margin is only defined if votes are present")    }    if( !is.factor(observed) ) {        stop(deparse(substitute(observed)), " is not a factor")    }    augD <- rf$votes    if( any(augD > 1) ) {        augD <- sweep(augD, 1, rowSums(augD), "/")    }    augD <- data.frame(augD, observed)    names(augD) <- c(dimnames(rf$votes)[[2]], "observed")    nlev <- length(levels(observed))        ans<- apply(augD, 1, function(x) { pos <- match(x[nlev+1], names(x));                                       t1 <- as.numeric(x[pos]);                                       t2 <- max(as.numeric(x[-c(pos, nlev+1)]));                                       t1 - t2 }                )    names(ans) <- observed    class(ans) <- "margin"    ans}plot.margin <- function(x, sort=TRUE, ...) {    if (sort) x <- sort(x)    nF <- factor(names(x))    nlevs <- length(levels(nF))    if ( require(RColorBrewer) && nlevs < 12) {        pal <- brewer.pal(nlevs,"Set1")    } else {        pal <- rainbow(nlevs)    }    plot.default(x, col=pal[as.numeric(nF)], pch=20, ... )}