activity (version 1.0)

compareTimes: Compare activity across between times of day

Description

Uses a Wald test to statistically compare activity levels at given radian times of day for a fitted activity distribution.

Usage

compareTimes(fit, times)

Arguments

fit

Fitted actmod object with errors boostrapped (fit using fitact with sample argument != "none").

times

Numeric vector of radian times of day at which to compare activity levels. All pairwise comparisons are made.

Value

A matrix with 4 columns: 1. differences between PDF values; 2. SEs of the differences; 3. Wald statistics; 4. p-values (H0 is no difference between estimates). Matrix rows give all possible pairwise comparisons, numbered in the order in which they appear in vector times.

Details

Bootrapping the activity model yields standard error estimates for the PDF. This function uses these SEs to compute a Wald statistic for the difference between PDF values (by inference activity levels) at given times of day: statistic W = (a1-a2)^2 / (SE1^2+SE2^2) tested on chi-sq distribution with 1 degree of freedom.

Examples

data(BCItime)
tPaca <- 2*pi*BCItime$time[BCItime$species=="paca"]
fPaca <- fitact(tPaca, reps=10)
plot(fPaca, hrs=FALSE, frq=FALSE)
compareTimes(fPaca, c(5.5,6,0.5,1))