activity (version 1.0)

compareAct: Compare activity level estimates

Description

Wald test for the statistical difference between two or more activitiy level estimates.

Usage

compareAct(fits)

Arguments

fits

A list of fitted actmod objects

Value

A matrix with 4 columns: 1. differences between estimates; 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 entered in the list fits.

Details

Uses a Wald test to ask whether the difference between estimates a1 and a2 is significantly different from 0: statistic W = (a1-a2)^2 / (SE1^2+SE2^2) tested on chi-sq distribution with 1 degree of freedom.

Examples

#Test whether paca have a sigificantly different activity level from rat.
#Bootstrap reps limited to speed up example.
data(BCItime)
tPaca <- 2*pi*BCItime$time[BCItime$species=="paca"]
tRat <- 2*pi*BCItime$time[BCItime$species=="rat"]
(fPaca <- fitact(tPaca, reps=10))
(fRat <- fitact(tRat, reps=10))
compareAct(list(fPaca,fRat))