hatvalues.rlmerMod: Robust leverage (hat values) for an rlmerMod fit.

In robustlmm: Robust Linear Mixed Effects Models

Robust leverage (hat values) for an rlmerMod fit.

Description

The self-leverage A_{ii} of each observation in the robust, random-effect-whitened convolution that the estimator uses internally – the robust analogue of the linear mixed-model hat value. It reduces to the classical lmer leverage at the non-robust limit (rho = cPsi); at the robust default the effective degrees of freedom \sum_i A_{ii} differ as downweighting changes each observation's pull. With groups set, the per-observation leverages are summed within each cluster, giving the cluster's leverage (its effective-df contribution).

Usage

## S3 method for class 'rlmerMod'
hatvalues(model, groups = NULL, ...)

Arguments

model	An rlmerMod object.
groups	Leverage aggregation: NULL (default) for per-observation; TRUE for the top-level grouping factor; or a factor / grouping-factor name to aggregate over.
...	Currently unused.

Value

Named numeric vector: one entry per observation (groups = NULL) or per cluster level.

See Also

cooks.distance, rlmer (the design.weights argument bounds high-leverage design points)

robustlmm documentation built on July 30, 2026, 5:11 p.m.