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lsr (version 0.5.2)

expandFactors: Expand factors to a set of contrasts

Description

Substitutes all factors in a data frame with the set of contrasts with which that factor is associated

Usage

expandFactors(data, ...)

Arguments

data

A data frame.

...

Additional arguments to be passed to model.matrix

Value

A data frame.

Details

The expandFactors function replaces all of the factors in a data frame with the set of contrasts output by the contrasts function or model.matrix. It may be useful for teaching purposes when explaining relationship between ANOVA and regression.

Examples

Run this code
# NOT RUN {
grading <- data.frame( teacher = factor( c("Amy","Amy","Ben","Ben","Cat") ),
                       gender = factor( c("male","female","female","male","male") ),
                       grade = c(75,80,45,50,65) )

# expand factors using the default contrasts (usually treatment contrasts)
expandFactors( grading )

# specify the contrasts using the contrasts.arg argument to model.matrix
my.contrasts <- list( teacher = "contr.helmert", gender = "contr.treatment" )
expandFactors( grading, contrasts.arg = my.contrasts )

# }

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