Returns the names of the predictor variables for the
different parts of a model (like fixed or random effects, zero-inflated
component, ...). Unlike find_parameters()
, the names from
find_predictors()
match the original variable names from the data
that was used to fit the model.
Usage
find_predictors(x, ...)
# S3 method for default
find_predictors(
x,
effects = c("fixed", "random", "all"),
component = c("all", "conditional", "zi", "zero_inflated", "dispersion", "instruments",
"correlation", "smooth_terms"),
flatten = FALSE,
verbose = TRUE,
...
)
# S3 method for afex_aov
find_predictors(
x,
effects = c("fixed", "random", "all"),
component = c("all", "conditional", "zi", "zero_inflated", "dispersion", "instruments",
"correlation", "smooth_terms"),
flatten = FALSE,
verbose = TRUE,
...
)
Arguments
- x
A fitted model.
- ...
Currently not used.
- effects
Should variables for fixed effects, random effects or both be returned? Only applies to mixed models. May be abbreviated.
- component
Should all predictor variables, predictor variables for the conditional model, the zero-inflated part of the model, the dispersion term or the instrumental variables be returned? Applies to models with zero-inflated and/or dispersion formula, or to models with instrumental variable (so called fixed-effects regressions). May be abbreviated. Note that the conditional component is also called count or mean component, depending on the model.
- flatten
Logical, if
TRUE
, the values are returned as character vector, not as list. Duplicated values are removed.- verbose
Toggle warnings.
Value
A list of character vectors that represent the name(s) of the
predictor variables. Depending on the combination of the arguments
effects
and component
, the returned list has following elements:
conditional
, the "fixed effects" terms from the modelrandom
, the "random effects" terms from the modelzero_inflated
, the "fixed effects" terms from the zero-inflation component of the modelzero_inflated_random
, the "random effects" terms from the zero-inflation component of the modeldispersion
, the dispersion termsinstruments
, for fixed-effects regressions likeivreg
,felm
orplm
, the instrumental variablescorrelation
, for models with correlation-component likegls
, the variables used to describe the correlation structure
Model components
Possible values for the component
argument depend on the model class.
Following are valid options:
"all"
: returns all model components, applies to all models, but will only have an effect for models with more than just the conditional model component."conditional"
: only returns the conditional component, i.e. "fixed effects" terms from the model. Will only have an effect for models with more than just the conditional model component."smooth_terms"
: returns smooth terms, only applies to GAMs (or similar models that may contain smooth terms)."zero_inflated"
(or"zi"
): returns the zero-inflation component."dispersion"
: returns the dispersion model component. This is common for models with zero-inflation or that can model the dispersion parameter."instruments"
: for instrumental-variable or some fixed effects regression, returns the instruments."location"
: returns location parameters such asconditional
,zero_inflated
,smooth_terms
, orinstruments
(everything that are fixed or random effects - depending on theeffects
argument - but no auxiliary parameters)."distributional"
(or"auxiliary"
): components likesigma
,dispersion
,beta
orprecision
(and other auxiliary parameters) are returned.