findbars {lme4} | R Documentation |
Determine random-effects expressions from a formula
Description
From the right hand side of a formula for a mixed-effects model, determine the pairs of expressions that are separated by the vertical bar operator. Also expand the slash operator in grouping factor expressions and expand terms with the double vertical bar operator into separate, independent random effect terms.
Usage
findbars(term)
Arguments
term |
a mixed-model formula |
Value
pairs of expressions that were separated by vertical bars
Note
This function is called recursively on individual terms
in the model, which is why the argument is called
term
and not a name like form
, indicating a
formula.
See Also
formula
, model.frame
,
model.matrix
.
Other utilities: mkRespMod
,
mkReTrms
, nlformula
,
nobars
, subbars
Examples
findbars(f1 <- Reaction ~ Days + (Days | Subject))
## => list( Days | Subject )
## These two are equivalent:% tests in ../inst/tests/test-doubleVertNotation.R
findbars(y ~ Days + (1 | Subject) + (0 + Days | Subject))
findbars(y ~ Days + (Days || Subject))
## => list of length 2: list ( 1 | Subject , 0 + Days | Subject)
findbars(~ 1 + (1 | batch / cask))
## => list of length 2: list ( 1 | cask:batch , 1 | batch)
[Package lme4 version 1.1-35.5 Index]