vcramer <- function (x, y = NULL) 
{
  if(!is.null(y)) {
  tab <- table(x, y)
  } else tab = as.matrix(x)
  
  n <- (min(nrow(tab), ncol(tab))-1) * margin.table(tab)
  chiq <- as.numeric(chisq.test(tab, correct = FALSE)$statistic)
  p <- chisq.test(tab, correct = FALSE)$p.value
  v = sqrt(chiq / n)
  res <- c("chi.sq" = chiq, "p" = p, "v di Cramer" = v)
  res
}