hcrabs | R Documentation |
Recorded are the numbers of male satellites, and other characteristics of 173 female horseshoe crabs.
data("hcrabs")
A data frame with 173 observations on the following 5 variables.
color
the female crab's color, coded 1: light; 2: medium light; 3: medium; 4: medium dark; 5: dark. Not all of these colors appear.
spine
the female crab's spine condition, coded 1: both good; 2: one worn or broken; 3: both worn or broker.
width
the female crab's carapace width (cm).
num.satellites
the number of satellite males.
weight
the female crab's weight (kg).
A nesting female horseshoe crab may have male crabs residing nearby, called satellites, besides the male crab residing in her nest. Brockmann (1996) investigated factors (including the female crab's color, spine condition, weight, and carapace width) which may influence the presence/obsence of satellite males. This data set has been discussed by Agresti (2002).
Dabao Zhang, Department of Statistics, Purdue University
Agresti, A. (2012). An Introduction to Categorical Data Analysis, 3rd edition. Wiley: New Jersey.
Brockmann, H. J. (1996). Satellite male groups in horseshoe crabs. Limulus polyphemus. Ethology, 102: 1-21.
rsq, rsq.partial, pcor, simglm
.
data(hcrabs)
summary(hcrabs)
head(hcrabs)
attach(hcrabs)
y <- ifelse(num.satellites>0,1,0)
bnfit <- glm(y~color+spine+width+weight,family=binomial)
rsq(bnfit)
rsq(bnfit,adj=TRUE)
rsq.partial(bnfit)
quasips <- glm(num.satellites~color+spine+width+weight,family=quasipoisson)
rsq(quasips)
rsq(quasips,adj=TRUE)
rsq.partial(quasips)
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.