Format a confusion matrix (removing zero entry for visual clarity)

format.confusion.matrix <- function(x)
{ 
    ## Purpose: Format a confusion matrix (removing zero entry for visual clarity)
    ##          Requires package "formattable". 
    ## Arguments:
    ##    x: a confusion matrix (nrow = ncol, with counts in each cell) 
    ## Return: a formated confusion matrix in html browser and in a CSV file. 
    ## Author: Feiming Chen, Date: 17 Apr 2017, 15:45
    ## ________________________________________________

    x1 <- as.character(as.matrix(x))
    x1[x1 == "0"] <- ""
    x2 <- matrix(x1, nrow(x), ncol(x), dimnames=dimnames((x)))
    write.csv(x2, file="Confusion-Matrix.csv")
    formattable::formattable(as.data.frame(x2))
}
if (F) {                                # Unit Test
    x <- matrix(c(3,1,0,1,4,0,0,1,6), 3, 3, dimnames = list(c("A", "B", "C"), c("A", "B", "C")))
    format.confusion.matrix(x)
}