R2MLwiN (version 0.2-1)

predLines: Draws predicted lines using a fitted model object

Description

This function draws predicted lines against an explanatory variable for selected groups at a higher (>=2) level.

Usage

predLines(object, indata, xname, lev=2, selected=NULL, probs=c(.025,.975), 
legend=TRUE, legend.space="top", legend.ncol=4, ...)

Arguments

object

Either "mlwinfitIGLS" or "mlwinfitMCMC" class object.

indata

An object (converts to data.frame) containing the data modelled.

xname

A name of an explanatory variable.

lev

A digit indicating the level (of the multilevel model) at which to plot.

selected

A vector specifying groups to selectively plot at the level specified in lev. If selected=NULL, then all groups at that level are included.

probs

A numeric vector of probabilities with values in (0,1) used to calculate the lower and upper quantiles from which the error bars are plotted. Currently, this is only available for a "mlwinfitIGLS" object.

legend

A logical value indicating whether a legend is to be added.

legend.space

A character string specifies one of the four sides, which can be one of "top", "bottom", "left" and "right". Default, legend.space="top".

legend.ncol

An integer specifies a number of columns, possibly divided into blocks, each containing some rows. Default, legend.ncol=2.

...

Other arguments to be pased to xyplot.

See Also

predCurves

Examples

library(R2MLwiN)
## Modify the following paths as appropriate.
## MLwiN folder
mlwin = "C:/Program Files (x86)/MLwiN v2.29/"
## MLwiN sample worksheet folder
wspath=paste(mlwin,"/samples/",sep="")


## Example: Normal
formula="normexam~(0|cons+standlrt)+(2|cons+standlrt)+(1|cons)"
levID=c('school','student')
estoptions= list(EstM=1,resi.store.levs=2)
wsfile=paste(wspath,"tutorial.ws",sep="")
inputfile=paste(tempdir(),"/tutorial.dta",sep="")
ws2foreign(wsfile, foreignfile=inputfile, MLwiNPath=mlwin)
library(foreign);indata =read.dta(inputfile)
mymodel=runMLwiN(formula, levID, D="Normal", indata, estoptions,MLwiNPath=mlwin)

predLines(mymodel, indata, xname="standlrt", lev = 2,
selected =c(30,44,53,59), probs=c(.025,.975))