warbleR (version 1.1.1)

coor.test: Randomization test for singing coordination

Description

coor.test Monte Carlo randomization test to assess the statistical significance of singing coordination

Usage

coor.test(X, iterations = 1000, less.than.chance = TRUE, parallel = 1)

Arguments

X

Data frame containing columns for singing event (sing.event), individual (indiv), and start and end time of signal (start and end).

iterations

number of iterations for shuffling and calculation of the expected number of overlaps. Default is 1000.

less.than.chance

Logical. If TRUE the test evaluates whether overlaps occur less often than expected by chance. If FALSE the opposite pattern is evaluted (whether overlaps occur more often than expected by chance). Default is TRUE.

parallel

Numeric. Controls whether parallel computing is applied. It specifies the number of cores to be used. Default is 1 (e.i. no parallel computing). windows OS users need to install warbleR from github to run parallel.

Value

• A data frame with the observed number of overlaps (obs.overlaps), mean number of overlaps expected by chance, and p value.

Details

This function calculates the probability of finding and equal or lower number (or higher if les.than.chance is TRUE) of song overlaps in a coordinated singing event. The function shuffles the sequences of signals and silence-between-signals for both individuals to produce a null distribution of expected number of overlaps by chance. The observed number of overlaps is compared to this expected values. The p-values are calculated as the proportion of random expected values that were lower (or higher) than the observed value. The function runs one test for each singing event in the input data frame. The function is equivalent to the "KeepGaps" methods described in Masco et al. 2015.

References

Masco, C., Allesina, S., Mennill, D. J., and Pruett-Jones, S. (2015). The Song Overlap Null model Generator (SONG): a new tool for distinguishing between random and non-random song overlap. Bioacoustics. 1-12.

Examples

#load  simulated singing data (see data documentation)
data(coor.sing)

# testing if coordination happens less than expected by chance
coor.test(coor.sing, iterations = 1000, less.than.chance = T)

# testing if coordination happens more than expected by chance
coor.test(coor.sing, iterations = 1000, less.than.chance = F)