[R] Generating a Special Histogram

[Duncan Murdoch]

On 05/01/2017 11:01 AM, Dan Abner wrote:
> Hi all,
>
> Is anyone aware of a package, function, or general R trick that would make
> generating histograms like the one in the attachment easy in R (i.e.,
> without manually drawing each individual horizontal line and specifying the
> coordinates for a textbox for each number)?
>
> I need to make ~12 of these for different samples of n=25, so the manual
> approach would be very painful...

You can write a function to do this pretty easily.  hist(..., 
plot=FALSE) does all the calculations for you; you just need to write 
the loop to draw the boxes.  For example,

myhist <- function(x) {
   histvals <- hist(x, plot = FALSE)
   with(histvals, {
     plot(range(breaks), range(c(0, counts)), type = "n")

     for (i in seq_along(histvals$counts)) {
       keep <- (breaks[i] < x & x <= breaks[i+1]) |
               (i == 1 & x == breaks[1])
       vals <- x[keep]
       for (j in seq_along(vals)) {
         rect(breaks[i], j-1, breaks[i+1], j)
         text(mids[i], j-0.5, vals[j])
       }
     }
   })
}

x <- round(rnorm(20, mean=166, sd=4))
myhist(x)

Duncan Murdoch