Rotate histogram in R or overlay a density in a barplot

Question

I would like to rotate a histogram in R, plotted by hist(). The question is not new, and in several forums I have found that it is not possible. However, all these answers date

Answer 1

I'm not sure whether it is of interest, but I sometimes want to use horizontal histograms without any packages and be able to write or draw at any position of the graphic.

That's why I wrote the following function, with examples provided below. If anyone knows a package to which this would fit well, please write me: berry-b at gmx.de

Please be sure not to have a variable hpos in your workspace, as it will be overwritten with a function. (Yes, for a package I would need to insert some safety parts in the function).

horiz.hist <- function(Data, breaks="Sturges", col="transparent", las=1, 
ylim=range(HBreaks), labelat=pretty(ylim), labels=labelat, border=par("fg"), ... )
  {a <- hist(Data, plot=FALSE, breaks=breaks)
  HBreaks <- a$breaks
  HBreak1 <- a$breaks[1]
  hpos <<- function(Pos) (Pos-HBreak1)*(length(HBreaks)-1)/ diff(range(HBreaks))
  barplot(a$counts, space=0, horiz=T, ylim=hpos(ylim), col=col, border=border,...)      
  axis(2, at=hpos(labelat), labels=labels, las=las, ...) 
  print("use hpos() to address y-coordinates") }

For examples

# Data and basic concept
set.seed(8); ExampleData <- rnorm(50,8,5)+5
hist(ExampleData)
horiz.hist(ExampleData, xlab="absolute frequency") 
# Caution: the labels at the y-axis are not the real coordinates!
# abline(h=2) will draw above the second bar, not at the label value 2. Use hpos:
abline(h=hpos(11), col=2)

# Further arguments
horiz.hist(ExampleData, xlim=c(-8,20)) 
horiz.hist(ExampleData, main="the ... argument worked!", col.axis=3) 
hist(ExampleData, xlim=c(-10,40)) # with xlim
horiz.hist(ExampleData, ylim=c(-10,40), border="red") # with ylim
horiz.hist(ExampleData, breaks=20, col="orange")
axis(2, hpos(0:10), labels=F, col=2) # another use of hpos()

One shortcoming: the function doesn't work with breakpoints provided as a vector with different widths of the bars.