burt <- function(table) {
 disj <- data.frame(lapply(1:ncol(table), function(i) {
 col <- table[, i]
  lev <- names(table)[i]
 n <- length(col)
 col <- as.factor(col)
 x <- matrix(0, n, length(levels(col)))
 x[(1:n) + n * (unclass(col) - 1)] <- 1
 dimnames(x) <- list(row.names(table), paste(lev,
 levels(col), sep = "."))
 return(x)
 }))
 burt <- as.matrix(t(disj)) %*% as.matrix(disj)
 burt <- data.frame(burt)
 names(burt) <- names(disj)
 row.names(burt) <- names(disj)
 return(burt)
 }

disj <- function(table) {
 return(data.frame(lapply(1:ncol(table), function(i) {
 col <- table[, i]
 lev <- names(table)[i]
 n <- length(col)
 col <- as.factor(col)
 x <- matrix(0, n, length(levels(col)))
 x[(1:n) + n * (unclass(col) - 1)] <- 1
 dimnames(x) <- list(row.names(table), paste(lev,
 levels(col), sep = "."))
 return(x)
 })))
 }