R - Binomial Distribution
Table of Contents
1 - About
2 - Articles Related
3 - Function
3.1 - Density
The binomial distribution with size = n and prob = p has density
p(x) = choose(n, x) p^x (1-p)^(n-x)
for x = 0, …, n
where:
- R - Choose (binomial coefficient)
3.2 - Cumulative
To find the probability of having k or less correct answers, we can plot a cumulative distribution.
plot(pbinom(0:40, size=20, prob=0.5) )
plot(pbinom(0:40, size=20, prob=0.7) )
plot(pbinom(0:40, size=40, prob=0.5) )
4 - Example
4.1 - Biased coin
The (Probability|Statistics) - Binomial Distribution example of the Binomial Distribution in R
require(graphics)
dbinom(0:5, size=6, prob=0.3)
[1] 0.117649 0.302526 0.324135 0.185220 0.059535 0.010206
where:
- 0:5 is a vector representing k (the trial index)
- size is n, the number of trial
- prob is the probability of a success trial