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Draw binary data with fixed intra-cluster correlation.

Source: R/draw_binary_icc.R
draw_binary_icc.Rd

Data is generated to ensure inter-cluster correlation 0, intra-cluster correlation in expectation ICC. Algorithm taken from Hossein, Akhtar. "ICCbin: An R Package Facilitating Clustered Binary Data Generation, and Estimation of Intracluster Correlation Coefficient (ICC) for Binary Data".

Usage

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

Arguments

prob

A number or vector of numbers, one probability per cluster. If none is provided, will default to 0.5.

N

(Optional) A number indicating the number of observations to be generated. Must be equal to length(clusters) if provided.

clusters

A vector of factors or items that can be coerced to clusters; the length will determine the length of the generated data.

ICC

A number indicating the desired ICC, if none is provided the default ICC will be 0.

Value

A vector of binary numbers corresponding to the observations from the supplied cluster IDs.

Examples

# Divide units into clusters
clusters = rep(1:5, 10)

# Default probability 0.5, default ICC 0
draw_binary_icc(clusters = clusters)
#>  [1] 0 0 0 0 1 1 0 1 0 1 1 0 1 1 1 0 0 0 0 1 1 0 1 1 0 0 0 1 0 0 1 1 0 1 1 1 0 1
#> [39] 0 0 0 0 0 1 1 0 0 0 1 1

# Specify probability or ICC
corr_draw = draw_binary_icc(prob = 0.5, clusters = clusters, ICC = 0.5)

# Verify ICC of data.
summary(lm(corr_draw ~ as.factor(clusters)))$r.squared
#> [1] 0.5142857