FootHead {heplots} | R Documentation |
Data collected as part of a preliminary study examining the relation between football helmet design and neck injuries. There are 30 subjects in each of three groups: High school football players, college players and non-football players.
data(FootHead)
A data frame with 90 observations on the following 7 variables.
group
High school
College
Non-football
width
circum
front.back
eye.top
ear.top
jaw
Rencher, A. C. (1995), Methods of Multivariate Analysis, New York: Wiley, Table 8.3.
data(FootHead) str(FootHead) # use Helmert contrasts for group contrasts(FootHead$group) <- contr.helmert contrasts(FootHead$group) foot.mod <- lm(cbind(width, circum,front.back,eye.top,ear.top,jaw)~group, data=FootHead) Manova(foot.mod) # show the HE plot for the first two variables heplot(foot.mod, main="HE plot") # show it with tests of Helmert contrasts heplot(foot.mod, hypotheses=list("group.1"="group1","group.2"="group2"), col=c("red", "blue", "green3", "green3" ), main="HE plot with orthogonal Helmert contrasts") # show all pairwise HE plots pairs(foot.mod) # ... with tests of Helmert contrasts pairs(foot.mod, hypotheses=list("group.1"="group1","group.2"="group2"), col=c("red", "blue", "green3", "green3"), hyp.labels=FALSE) # see that the hypothesis for groups really is 2D heplot3d(foot.mod, variables=c(1,2,6), hypotheses=list("group.1"="group1","group.2"="group2"), col=c("red", "blue", "green3", "green3" ), wire=FALSE)