RVAideMemoire (version 0.9-45-2)

user.cont: User defined contrasts for LSMeans

Description

Returns a function usable by lsmeans for user defined contrasts.

Usage

user.cont(cont)

Arguments

cont

any matrix of contrasts (see 'Details').

Value

• user.cont.lsmc
  the function to be called by lsmeans

Details

In these matrices, each line is a comparison (= contrast) and each colum is a level of the factor. Rules for writing contrasts are: - levels not involved in the comparison must have a null value - levels to be compared must have opposite signs - levels can be grouped (for example 2 -1 -1 give a comparison of the first level against the group composed by the two others) - the sum of all values of a contrast must be null.

See Also

lsmeans

Examples

require(car)
require(lsmeans)

response <- c(rpois(30,1),rpois(30,3),rpois(30,10)) 
fact <- gl(3,30,labels=LETTERS[1:3])
model <- glm(response~fact,family="poisson")
Anova(model)
mat <- matrix(c(1,-1,0,0,1,-1,2,-1,-1),nrow=3,byrow=TRUE,dimnames=list(levels(fact),1:3))
mat
cont.lsmc <- user.cont(mat)
lsmeans(model,cont~fact)