In colefh/roller: Rolls a die

knitr::opts_chunk$set(collapse = T, comment = "#>")
library(roller)

Dice Rolling

The package "roller" is a very simple implementation of rolling a multi-sided dice with certain sides and probabilities, and visualizing the outcomes in multiple ways including plots and tables of the frequencies of each side rolled.

Creating a Device

The first step in rolling a dice is creating the dice (or device) to be rolled. We need to create a "device" object using the function device().

my_device <- device()
my_device

By default, the device() function creates a fair, 2 sided object with sides 1 and 2 and probabilites 50% each. You can change the defaults with input arguments sides and prob.

fair_six_sided <- device(sides = 1:6, prob = rep(1/6, 6))
fair_six_sided
loaded_four_sided <- device(sides = 1:4, prob = c(0.7,0.1,0.1,0.1))
loaded_four_sided

Rolling a Device/Dice

Once we've created our device, we can use the roll() function to roll the device. We control which device we roll and how many times we roll it with the inputs device and times respectively. This function will output a list of 4 elements: rolls (the roll outputs), sides (the sides of device), prob (the probabilities for each side of device), and total (the total number of rolls, e.g. times).

rolled200 <- roll(device(sides = 1:6, prob = rep(1/6.6)), 200)
rolled200

The summary() function returns a list containing a data frame of the counts and frequencies of each side rolled.

summary200 <- summary(rolled200)
summary200

The plot() method yields a barchart of the proportions of each side rolled.

plot(rolled200)

The "[" (extraction) method allows us to examine individual rolls.

rolled200[150]

The `"[<-" method allows us to replace the value of a given roll.

rolled200[150] <- 5
rolled200[150]
rolled200[150] <- 1
rolled200[150]

the "+" method allows us to add rolls to an already rolled object.

rolled300 <- rolled200 + 100
summary(rolled300)

colefh/roller documentation built on May 13, 2019, 11:33 a.m.