caseweightIF: Case-weight (Hampel) influence function of the fixed effects...

In robustlmm: Robust Linear Mixed Effects Models

Case-weight (Hampel) influence function of the fixed effects of a fitted rlmerMod object.

Description

Returns IF(y_i) = -\hat{J}^{-1} \psi(\hat{par}; y_i) (the Hampel object built from the score value \psi), reusing the Jacobian \hat{J} formed by implicitIF. This is the right object for robustness quantities (gross-error sensitivity, breakdown), distinct from the local-shift sensitivity returned by implicitIF for a redescending \psi.

Usage

caseweightIF(fit, idx = NULL, use.expected = FALSE)

Arguments

fit	An rlmerMod object.
idx	Optional integer indices selecting observations to compute (default: all observations).
use.expected	Passed to implicitIF; default FALSE (empirical Jacobian).

Details

\hat{\sigma}, \hat{\theta} are held fixed (partial IF).

Value

A list with IF_beta (p \times |idx|), IF_u (q \times |idx|), IF_b, and the per-observation score-contribution columns Gb_cw, Gu_cw.

See Also

vcov_sandwich, vcov

robustlmm documentation built on June 21, 2026, 5:12 p.m.