Multinomial Distribution

Multinomial Distribution

Multinomial distribution is a generalization of binomial distribution.

It describes outcomes of multi-nominal scenarios unlike binomial where scenarios must be only one of two. e.g. Blood type of a population, dice roll outcome.

It has three parameters:

  • n- number of times to run the experiment.
  • pvals- list of probabilities of outcomes (e.g. [1/6, 1/6, 1/6, 1/6, 1/6, 1/6] for dice roll).
  • size- The shape of the returned array.

Example

Draw out a sample for dice roll:

from numpy import random

x = random.multinomial(n=6, pvals=[1/6, 1/6, 1/6, 1/6, 1/6, 1/6])

print(x)

Note:Multinomial samples will NOT produce a single value! They will produce one value for each pval.

Note:As they are generalization of binomial distribution their visual representation and similarity of normal distribution is same as that of multiple binomial distributions.