R Dataset / Package DAAG / possum
On this R-data statistics page, you will find information about the possum data set which pertains to Possum Measurements. The possum data set is found in the DAAG R package. You can load the possum data set in R by issuing the following command at the console data("possum"). This will load the data into a variable called possum. If R says the possum data set is not found, you can try installing the package by issuing this command install.packages("DAAG") and then attempt to reload the data with the library() command. If you need to download R, you can go to the R project website. You can download a CSV (comma separated values) version of the possum R data set. The size of this file is about 6,399 bytes.
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.