fixef.lmekin {coxme}R Documentation

Extraction functions for Lmekin

Description

Extract the fixed effects, random effects, variance of the fixed effects, or variance of the random effects from a linear mixed effects model fit with lmekin.

Usage

## S3 method for class 'lmekin'
fixef(object, ...)
## S3 method for class 'lmekin'
ranef(object, ...)
## S3 method for class 'lmekin'
vcov(object, ...)
## S3 method for class 'lmekin'
VarCorr(x, ...)
## S3 method for class 'lmekin'
logLik(object, ...)

Arguments

object

an object inheriting from class lmekin representing the result of a mixed effects model.

x

an object inheriting from class lmekin representing the result of a mixed effects model.

...

some methods for this generic require additional arguments. None are used in this method.

Details

For the random effects model y=Xβ+Zb+ϵy = X\beta + Zb + \epsilon, let σ2\sigma^2 be the variance of the error term ϵ\epsilon. Let A=σ2PA= \sigma^2 P be the variance of the random effects bb. There is a computational advantage to solving the problem in terms of PP instead of AA, and that is what is stored in the returned lmekin object. The VarCorr function returns elements of PP; the print and summary functions report values of AA. Pinhiero and Bates call PP the precision factor.

Value

the fixed effects are a vector and vcov returns their variance/covariance matrix. The random effects are a list with one element for each random effect. The ranef component contains the coefficients and VarCorr the estimated variance/covariance matrix. The logLik method returns the loglikelihood along with its degrees of freedom.

Author(s)

Terry Therneau

References

J Pinheiro and D Bates, Mixed-effects models in S and S-Plus. Springer, 2000.

See Also

lmekin, random.effects, fixed.effects, link{vcov}, VarCorr

Examples

data(ergoStool, package="nlme")  # use a data set from nlme
efit <-  lmekin(effort ~ Type + (1|Subject), ergoStool)
ranef(efit)

[Package coxme version 2.2-20 Index]