add_term: Add or remove terms to a lmer formula string

In MaksimRudnev/LittleHelpers: Helpers for comparative studies

Add or remove terms to a lmer formula string

Description

Add or remove terms to a lmer formula string

Usage

add_term(x, fixed = NULL, random = NULL, drop = NULL, drop.random = NULL, ...)

Arguments

x	Either mer formula object, string containing formula, lmer object. If latter is the case, the updated object will be returned instead of a new formula.
fixed	List of character strings containing variable names or terms to include in the formula as fixed terms.
random	List of character strings containing variable names or terms to include in the formula as random terms.
drop	List of character strings containing variable names or fixed terms to exclude from the formula.
drop.random	List of character strings containing variable names or random terms to exclude from the formula.
...	Extra arguments passed to 'update'. Works only if 'x' is a lmer object.

Examples

f1 <- "a ~ b + c + (1| group)"
add_term(f1, , "Conservation")
add_term(f1, "Conservation*GDP")
add_term(f1, "Conservation*GDP", "Conservation")

add_term(f1, drop="female", drop.random = "g.agea")

MaksimRudnev/LittleHelpers documentation built on June 10, 2025, 12:58 p.m.