Sample pairs of correlated binary events

Source: R/ranBin2.R

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

ranBin2(nRep, u, psi)

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.

Value

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

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
#>            [,1]       [,2]
#> [1,]  1.0000000 -0.3033398
#> [2,] -0.3033398  1.0000000
colMeans(s)  # Event rates as expected
#> [1] 0.826 0.296