rmulti: Random draws from a multinomial distribution

In poLCAParallel: Polytomous Variable Latent Class Analysis Parallel

Random draws from a multinomial distribution

Description

One random draw from a multinomial distribution or list of multinomial distributions.

Usage

rmulti(p)

Arguments

p	matrix of dimension n by r containing probabilities, for each row, of drawing each of r outcomes. p may also be entered as a vector, in which case rmulti treats it as a matrix of dimension n=1 by r. Each row of matrix p must sum to 1 or rmulti will not work properly.

Value

A vector of length n. Each item represents one draw from the multinomial distribution parameterized by the outcome probabilities in each row of p.

Examples

##
## One draw from a three-category multinomial distribution.
##
p1 <- c(0.7, 0.2, 0.1)
rmulti(p1)

##
## 10,000 draws from a three-category multinomial distribution.
##
n <- 10000
p2 <- matrix(p1, nrow = n, ncol = length(p1), byrow = TRUE)
rmdraws <- rmulti(p2)
table(rmdraws) / n # should be approximately 0.7, 0.2, 0.1

##
## 10,000 draws from a mixture of three groups of a
## four-category multinomial distribution.
##
group.p <- matrix(c(0.5, 0.3, 0.2), nrow = n, ncol = 3, byrow = TRUE)
group <- rmulti(group.p)
p3 <- t(matrix(NA, nrow = n, ncol = 4))
p3[, group == 1] <- c(0.7, 0.1, 0.1, 0.1)
p3[, group == 2] <- c(0.1, 0.7, 0.1, 0.1)
p3[, group == 3] <- c(0.1, 0.1, 0.1, 0.7)
p3 <- t(p3)
rmdraws3 <- rmulti(p3)
table(group, rmdraws3)
table(group, rmdraws3) / rowSums(table(group, rmdraws3))

poLCAParallel documentation built on Feb. 20, 2026, 1:09 a.m.