contr.custom: Build a custom contrast and k-2 orthogonal ones

In mcfanda/cpower: Power analysis for contrasts

Description

Creates a set of contrast codes that are orthogonal to a given one with the aim of testing the given contrast in a linear model

Usage

contr.custom(cont)

Arguments

cont	vector of contrast weight (numeric).

Value

a data.frame with k-1 contrast codes, with k=length(cont). It can be used to assing contrast weights using contrasts

Author(s)

Marcello Gallucci, [e-mail]

Examples

### sim some data
cont<-c(-3,-1,1,3)
means<-c(10,12,10,12)
y<-rep(means,1000)+rnorm(4000,0,2)
x<-factor(rep(1:4,1000))
### assign contrast weights
contrasts(x)<-contr.custom(cont)
contrasts(x)
cor(contr.custom(cont))
summary(lm(y~x))

mcfanda/cpower documentation built on May 28, 2019, 1 p.m.