Possum Measurements
Description
The possum data frame consists of nine morphometric
measurements on each of 104 mountain brushtail possums, trapped
at seven sites from Southern Victoria to central Queensland.
Usage
possum
Format
This data frame contains the following columns:
- case
observation number
- site
one of seven locations where possums were
trapped
- Pop
a factor which classifies the sites as
Vic Victoria,
other New South Wales or Queensland
- sex
a factor with levels
f female,
m male
- age
age
- hdlngth
head length
- skullw
skull width
- totlngth
total length
- taill
tail length
- footlgth
foot length
- earconch
ear conch length
- eye
distance from medial canthus to lateral canthus of
right eye
- chest
chest girth (in cm)
- belly
belly girth (in cm)
Source
Lindenmayer, D. B., Viggers, K. L., Cunningham, R. B., and
Donnelly, C. F. 1995. Morphological variation among columns of the
mountain brushtail possum, Trichosurus caninus Ogilby
(Phalangeridae: Marsupiala). Australian Journal of Zoology 43:
449-458.
Examples
boxplot(earconch~sex, data=possum)
pause()sex <- as.integer(possum$sex)
oldpar <- par(oma=c(2,4,5,4))
pairs(possum[, c(9:11)], pch=c(0,2:7), col=c("red","blue"),
labels=c("tail\nlength","foot\nlength","ear conch\nlength"))
chh <- par()$cxy[2]; xleg <- 0.05; yleg <- 1.04
oldpar <- par(xpd=TRUE)
legend(xleg, yleg, c("Cambarville", "Bellbird", "Whian Whian ",
"Byrangery", "Conondale ","Allyn River", "Bulburin"), pch=c(0,2:7),
x.intersp=1, y.intersp=0.75, cex=0.8, xjust=0, bty="n", ncol=4)
text(x=0.2, y=yleg - 2.25*chh, "female", col="red", cex=0.8, bty="n")
text(x=0.75, y=yleg - 2.25*chh, "male", col="blue", cex=0.8, bty="n")
par(oldpar)
pause()sapply(possum[,6:14], function(x)max(x,na.rm=TRUE)/min(x,na.rm=TRUE))
pause()here <- na.omit(possum$footlgth)
possum.prc <- princomp(possum[here, 6:14])
pause()plot(possum.prc$scores[,1] ~ possum.prc$scores[,2],
col=c("red","blue")[as.numeric(possum$sex[here])],
pch=c(0,2:7)[possum$site[here]], xlab = "PC1", ylab = "PC2")
# NB: We have abbreviated the axis titles
chh <- par()$cxy[2]; xleg <- -15; yleg <- 20.5
oldpar <- par(xpd=TRUE)
legend(xleg, yleg, c("Cambarville", "Bellbird", "Whian Whian ",
"Byrangery", "Conondale ","Allyn River", "Bulburin"), pch=c(0,2:7),
x.intersp=1, y.intersp=0.75, cex=0.8, xjust=0, bty="n", ncol=4)
text(x=-9, y=yleg - 2.25*chh, "female", col="red", cex=0.8, bty="n")
summary(possum.prc, loadings=TRUE, digits=2)
par(oldpar)
pause()require(MASS)
here <- !is.na(possum$footlgth)
possum.lda <- lda(site ~ hdlngth+skullw+totlngth+ taill+footlgth+
earconch+eye+chest+belly, data=possum, subset=here)
options(digits=4)
possum.lda$svd # Examine the singular values
plot(possum.lda, dimen=3)
# Scatterplot matrix - scores on 1st 3 canonical variates (Figure 11.4)
possum.lda
--
Dataset imported from https://www.r-project.org.