mixmeta (version 1.2.2)

terms.mixmeta: Extract Model Terms from mixmeta Objects

Description

These method function returns the terms object that defines meta-analytical models represented in objects of class "mixmeta".

Usage

# S3 method for mixmeta
terms(x, type="fixed", ...)

Value

An object of class c("terms","formula") which contains the terms representation of a symbolic meta-analytical model. See terms.object for its structure.

Arguments

x

an object of class "mixmeta".

type

the type of terms. Either "fixed" or "full". See Details.

...

further arguments passed to or from other methods.

Author

Antonio Gasparrini <>

Details

The terms object is produced by mixmeta when fitting the meta-analytical model, and stored as an attribute of the model.frame. Note that this object consists of terms for both the fixed and random-effects parts, the latter including also the grouping factors.

By using the default type="fixed", this method function removes the random-effects terms. This can then be used, for instance, for creating the model.matrix for the fixed effects. Otherwise with type="full", the full set of terms is returned.

See Also

See the methods model.frame and model.matrix.

Examples

# RUN A MODEL
model <- mixmeta(effect, var, random= ~ 1|district/study, data=school)

# TERMS (FIXED AND FULL)
terms(model)
terms(model, "full")
attr(model.frame(model), "terms")