trialr (version 0.1.6)

ranBin2: Sample pairs of correlated binary events

Description

This function is reproduced from the binarySimCLF package on CRAN. The original package appears no longer to be maintained. View the original source at: https://github.com/cran/binarySimCLF/blob/master/R/ranBin2.R

Usage

ranBin2(nRep, u, psi)

Value

Matrix of events represented as 0s and 1s, with nRep rows and 2 columns. The first column is the incidence of event 1.

Arguments

nRep

Number of simulated event pairs, positive integer.

u

Mean event probabilities, expressed as a vector of length 2. E.g. to simulate associated bivariate events with probabilities 80 u = c(0.8, 0.3).

psi

Odds ratio, number. This parameter controls the strength of association. Use psi = 1 for no association. Values greater than 1 correspond to increasingly positive association between the two events, and vice-versa.

Examples

probs <- c(0.8, 0.3)
s <- ranBin2(1000, probs, psi=0.2)  # 1000 pairs of outcomes
cor(s)  # Negatively correlated because psi < 1
colMeans(s)  # Event rates as expected