eRm (version 1.0-9)

plotGR: Plot Treatment or Covariate Effects for LLRA

Description

Plots treatment or covariate group effects over time.

Usage

plotGR(object, ...)

Arguments

object

an object of class "llra".

...

Additional parameters to be passed to and from other methods.

Author

Thomas Rusch

Warning:

Objects of class "llra" that contain estimates from a collapsed data matrix will not be displayed correctly.

Details

The plot is a lattice plot with each panel corresponding to an item. The effects are plotted for each groups (including baseline) over the different time points. The groups are given the same names as for the parameter estimates (derived from groupvec).

Please note that all effects are to be interpreted relative to the baseline.

Currently, this function only works for a full item x treatment x timepoints LLRA. Collapsed effects will not be displayed properly.

See Also

The plot method for trend effects plotTR.

Examples

##Example 6 from Hatzinger & Rusch (2009)
groups <- c(rep("TG",30),rep("CG",30))
llra1 <- LLRA(llradat3,mpoints=2,groups=groups)
summary(llra1)
plotGR(llra1)

if (FALSE) {  
##An LLRA with 2 treatment groups and 1 baseline group, 5 items and 4
##time points. Item 1 is dichotomous, all others have 3, 4, 5, 6
##categories respectively.
ex2 <- LLRA(llraDat2[1:20],mpoints=4,groups=llraDat2[21])
plotGR(ex2)}