Question

I have a roulette wheel simulation that plots a frequency versus roulette wheel slot (or factor) but I would also like to view % relative frequency vs. factor.

black_on_wheel = paste("B", 1:18, sep = "") 
red_on_wheel = paste("R", 1:18, sep = "")
roulette_wheel = c(red_on_wheel, black_on_wheel, "0", "00")
simulated_roulette_wheel = sample(roulette_wheel, size=500, replace = TRUE)
plot(rw_runs)

Answer 1

As @joran pointed out, you can use table and prop.table:

set.seed(001) # For the simulation to be reproducible.
simulated_roulette_wheel = sample(roulette_wheel, size=500, replace = TRUE)

tab <-table(simulated_roulette_wheel)                  # Frequency of each factor
prop.tab <- prop.table(tab) * 100                      # % Relative Freq.
barplot(prop.tab, xaxs='i', ylab="Relative %") ; box() # Barplot

In barplot, xaxs="i" allows the bars to start at the origin in x coordinate and the function box() adds a box to the plot.

The first ten elements of prop.tab looks like:

prop.tab[1:10]
simulated_roulette_wheel
  0  00  B1 B10 B11 B12 B13 B14 B15 B16 
2.4 2.8 4.6 3.4 2.2 3.0 1.8 2.4 2.2 2.2 

If you don’t multiply prop.table(tab) by 100, then you will only obtain a proportion instead of relative percentage.

Here’s the barplot generated: