UN: Unstructured Structure

Description Usage Arguments Details Value Examples

View source: R/structure.R

Description

Variance-covariance structure where the residuals have time-specific variance and correlation. Can be stratified on a categorical variable.

Usage

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UN(formula, var.cluster, var.time, ...)

Arguments

formula

formula indicating the cluster, factors influencing the variance and the correlation, and a possible stratification.

var.cluster

[character] used to check the cluster variable in the formula.

var.time

[character] used to check the time variable in the formula.

...

not used.

Details

A typical formula would be ~time or ~time|id, indicating a time-specific variance parameter and a correlation parameter specific to each pair of times.

Value

An object of class UN that can be passed to the argument structure of the lmm function.

Examples

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UN(~time|id)
UN(~time+gender|id)
UN(group~time|id, var.cluster = "id")
UN(group~time|id, var.cluster = "id", var.time = "time")

LMMstar documentation built on Nov. 5, 2021, 1:07 a.m.