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Draw binary data with a target intra-cluster correlation

Source: R/draw_icc.R
draw_binary_icc.Rd

Uses the mixture-of-Bernoullis model: with probability \(\sqrt{ICC}\) each unit takes the cluster-level draw; otherwise it takes an independent draw. This produces an expected ICC of the specified value.

Usage

draw_binary_icc(clusters, prob = 0.5, ICC = 0, N = NULL)

Arguments

clusters

Vector of cluster IDs.

prob

Cluster success probability. Scalar or per-cluster vector. Default 0.5.

ICC

Target ICC. Default 0 (independent draws).

N

Optional; must equal length(clusters).

Value

An integer vector of 0s and 1s of the same length as clusters, in the order the clusters were given.

Examples

clusters <- rep(1:10, each = 20)
y <- draw_binary_icc(clusters = clusters, prob = 0.5, ICC = 0.3)
summary(lm(y ~ factor(clusters)))$r.squared  # approx 0.3
#> [1] 0.312