Contrasts: Estimate Contrasts for Mixor Object

In mixor: Mixed-Effects Ordinal Regression Analysis

Estimate Contrasts for Mixor Object

Description

This function is used to specify and estimate contrasts of interest for a mixor object.

Usage

Contrasts(fit, contrast.matrix, digits=max(3, getOption("digits") - 2), 
   signif.stars=TRUE, dig.tst = max(1, min(5, digits - 1)))

Arguments

fit	A mixor object.
contrast.matrix	A matrix of contrasts of interest. Each column in the contrast matrix should be of the same length as the coef vector of the fitted mixor object.
digits	minimum number of significant digits to be used for most numbers.
signif.stars	logical; if TRUE, P-values are additionally encoded visually as "significance stars" in order to help scanning of long coefficient tables.
dig.tst	minimum number of significant digits for the test statistics.

Value

A list containing the following components:

contrast.matrix	a matrix specifying the contrasts of interest.
Contrasts	a matrix containing the estimates, SEs, Z-values, and p-values for the contrasts of interest.

Author(s)

Kellie J. Archer, Donald Hedeker, Rachel Nordgren, Robert D. Gibbons

See Also

See Also as mixor, coef.mixor, vcov.mixor

Examples

library("mixor")
data("SmokingPrevention")
# data frame must be sorted by id variable
SmokingPrevention<-SmokingPrevention[order(SmokingPrevention$class),]
Fitted.students<-mixor(thksord~thkspre+cc+tv+cctv, data=SmokingPrevention, 
     id=class, link="logit")
summary(Fitted.students)
coef(Fitted.students)
vcov(Fitted.students)
cm<-matrix(c(-1,-1,-1,0,0,0,0,0,
              0, 0, 0,0,0,0,0,0,
			  0, 0, 0,1,0,0,0,1),ncol=3,byrow=TRUE)
Contrasts(Fitted.students, contrast.matrix=cm)

mixor documentation built on July 3, 2026, 9:07 a.m.