多項分布からサンプリングする

gistfile1.lua

local function samplingFromMultinomialDistribution(probabilities)
  local accumulateProbability = 0

  local accumulateProbabilities = {}
  for i = 1, #probabilities do
    accumulateProbability = accumulateProbability + probabilities[i]
    table.insert(accumulateProbabilities, accumulateProbability)
  end

  local random = math.random()

  for i = 1, #accumulateProbabilities do
    if random < accumulateProbabilities[i] then
      return i
    end
  end
end

local probabilities = { 0.6, 0.2, 0.1, 0.05, 0.04, 0.01 }

local count = { 0, 0, 0, 0, 0, 0 }
for i = 1, 10000 do
  local index = samplingFromMultinomialDistribution(probabilities)
  count[index] = count[index] + 1
end
for i = 1, #count do
  print(count[i])
end