R2MLwiN (version 0.1-7)

predCurves: Draws predicted curves (lines) using estimates from the fixed part of a fitted model.

Description

This function draws predicted curves (lines) against an explanatory variable for each category of a categorical variable.

Usage

predCurves(object, indata, xname, group = NULL, legend = T, 
legend.space="top", legend.ncol=2, ...)

Arguments

object

Either "mlwinfitIGLS" or "mlwinfitMCMC" class object.

indata

A data.frame object containing the data.

xname

A name of an explanatory variable.

group

A character name or a factor (or vector) specifying a categorical variable. group=NULL by default.

legend

A logical value indicating whether a legend for group 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

predLines

Examples

library(R2MLwiN)
## Modify the following paths as appropriate.
## MLwiN folder
mlwin = "C:/Program Files (x86)/MLwiN v2.27/"
## MLwiN sample worksheet folder
wsfile=paste(mlwin,"/samples/alevchem.ws",sep="")
## the tutorial.dta will be save under the temporary folder
inputfile=paste(tempdir(),"/alevchem.dta",sep="")
ws2foreign(wsfile, foreignfile=inputfile, MLwiNPath=mlwin)
library(foreign);indata =read.dta(inputfile)
indata["gcseav"]=double2singlePrecision(indata["gcse-tot"]/indata["gcse-no"]-6)
indata["gcse^2"]=double2singlePrecision(indata["gcseav"]^2)
indata["gcse^3"]=double2singlePrecision(indata["gcseav"]^3)

## Example: A-level Chemistry
formula="a-point ~ (0|cons+gcseav+gcse^2+gcse^3+gender)+(1|cons )"
levID='pupil'
estoptions= list(EstM=1)
## Fit the model
mymodel=runMLwiN(formula, levID, D='Normal', indata, estoptions, MLwiNPath=mlwin)

predCurves(mymodel, indata,xname="gcseav", group="gender")