culcitalvolume: Coral-eating seastar Culcita novaeguineae data (volume loss version)

Description

This is the same experiment outlined in culcitalogreg except this data set only contains values where predation occurred, and the original volume as well as volume lost was recorded.

Usage

data("culcitalvolume")

Arguments

Format

A data frame with 50 observations on the following 7 variables.

ttt

represents the combinations of different symbionts, which the treatment condition is explicitly written in plain language.

volume

describes the size of the coral, measured in cm\(^3\).

predvolume

the amount of volume loss from the coral, measured in cm\(^3\).

crab

describes whether the crab was present in the experiment. n: not present, y: present.

shrimp

describes whether the shrimp was present in the experiment. n: not present, y: present.

block

a numeric variable indicating the experimental block. There are 10 blocks in total, each corresponding to a large, octagonal, flow-through seawater tank approximately 0.5m deep and 2m in diameter.

ttt2

a relabelled version of ttt.

1: no exosymbionts,
2: pair of Alpheus lottini only (Alpheus; shrimp),
3: pair of Trapezia serenei only (Trapezia; crab),
4: pair of Alpheus lottini and pair of Trapezia serenei (‘Alpheus and Trapezia’).

References

mckeon2012multiplelme4

Examples

Run this code

## Modifying to create a new response variable
vdata <- transform(culcitalvolume, 
                   propeaten = predvolume/volume,
                   tvol = log(predvolume))
## One-way analysis
(cvm1 <- lmer(tvol ~ ttt2 + (1|block), data = vdata))
(cvm2 <- lmer(propeaten ~ ttt2 + (1|block), data = vdata))
## Two-way analysis 
(cvm3 <- lmer(tvol ~ crab*shrimp + (1|block), data = vdata))
(cvm4 <- lmer(propeaten ~ crab*shrimp + (1|block), data = vdata))