| beetles {datana} | R Documentation |
Population density of beetles on time.
Description
Time series of population densities of experiments under controlled conditions in which flour beetles (Tribolium confusum) are kept in environments of known size. The period from egg to adult is approximately forty days at 27C degrees, and beetles were subject to different diets of whole wheat flour. The data are fully documented in Champman (1928).
Usage
data(beetles)
Format
The data contains the following four columns:
- days
days since the beginning of the experiment.
- diet
diet of whole wheat flour, in gr.
- type
type of individual: egg, larvae, pupae, adult.
- density
number of individuals.
Source
Data were digited by Yamara Arancibia, an undergraduate student of Prof Christian Salas-Eljatib at the Universidad Mayor, Santiago, Chile.
References
- Champman RN. 1928. The Quantitative Analysis of Environmental Factors. Ecology 9(2):111-122. doi:10.2307/1929348
Examples
data(beetles)
df<-beetles
name.diets<-unique(df$diet)
num.diets<-length(name.diets)
#Time series curves, such as in Fig.1 of the paper
#(i) firstly, we need to compute the following
alys<-with(df,tapply(density, list(as.factor(days),as.factor(diet)),sum))
out<-as.data.frame(alys)
out$time<-row.names(out)
#(ii) secondly, to plot
matplot(out[,"time"], out[,1:num.diets], las=1, type=c("b"),pch=1,
xlab="Time in days",ylab="Total individuals")
legend("topleft", legend = name.diets, title = "Diet (gr)",
col = 1:num.diets, lty = 1:num.diets, pch = 1)