vc: Extract variance components from mixed models

Description

Extract the variance components from a fitted model. Currently supports asreml, lme4, mmer, nlme and mcmc.list objects.

Usage

vc(object, ...)
# S3 method for default
vc(object, ...)
# S3 method for asreml
vc(object, gamma = FALSE, ...)
# S3 method for lme
vc(object, ...)
# S3 method for glmerMod
vc(object, ...)
# S3 method for lmerMod
vc(object, ...)
# S3 method for mcmc.list
vc(object, quantiles = c(0.025, 0.5, 0.975), ...)
# S3 method for mmer
vc(object, ...)

Value

A data frame or other object.

Arguments

object: A fitted model object
...: Not used. Extra arguments.
gamma: If gamma=FALSE, then the 'gamma' column is omitted from the results from asreml
quantiles: The quantiles to use for printing mcmc.list objects

Details

The extracted variance components are stored in a data frame with an additional 'vc.xxx' class that has an associated print method.

Examples

Run this code


if (FALSE) {

require("nlme")
data(Rail)
m3 <- lme(travel~1, random=~1|Rail, data=Rail)
vc(m3)
##       effect variance stddev
##  (Intercept)   615.3  24.81
##     Residual    16.17  4.021

require("lme4")
m4 <- lmer(travel~1 + (1|Rail), data=Rail)
vc(m4)
##      grp        var1 var2   vcov  sdcor
##     Rail (Intercept)  615.3  24.81
## Residual           16.17  4.021 

require("asreml")
ma <- asreml(travel~1, random=~Rail, data=Rail)
vc(ma)
##         effect component std.error z.ratio constr
##  Rail!Rail.var    615.3      392.6     1.6    pos
##     R!variance     16.17       6.6     2.4    pos

# See vignette for rjags example

# To change the number of digits, use the print function.
print(vc(m3), dig=5)

}