Description Usage Format Source Examples

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.

1 |

A data frame with 90 observations on the following 7 variables.

`group`

a factor with levels

`High school`

`College`

`Non-football`

`width`

a numeric vector: head width at widest dimension

`circum`

a numeric vector: head circumference

`front.back`

a numeric vector: front to back distance at eye level

`eye.top`

a numeric vector: eye to top of head

`ear.top`

a numeric vector:ear to top of head

`jaw`

a numeric vector: jaw width

Rencher, A. C. (1995), *Methods of Multivariate Analysis*,
New York: Wiley, Table 8.3.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 | ```
data(FootHead)
str(FootHead)
require(car)
# 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 for width and circumference", fill=TRUE,
col=c("red", "blue"))
# 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
if(requireNamespace("rgl")){
heplot3d(foot.mod, variables=c(1,2,6),
hypotheses=list("group.1"="group1","group.2"="group2"),
col=c("red", "blue", "green3", "green3" ), wire=FALSE)
}
``` |

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