terms.mixmeta {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 class 'mixmeta'
terms(x, type="fixed", ...)

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.

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.

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.

Author(s)

Antonio Gasparrini <[e-mail]>

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")