| vSRI {assocInd} | R Documentation |
The very Simple Ratio Index
Description
Calculates the very Simple Ratio Index
Usage
vSRI(x, Yab)
Arguments
x |
Number of times individuals a and b were observed together |
Yab |
Number of times individuals a and b were observed at the same time but not associating |
Details
The very simple ratio index calculates the probability that two individuals are observed together given that both have been seen. This index is useful if there is large individual identification error and is an unbiased estimate (however it requires the majority of groups in the study to be sampled in a given sampling period).
Value
Returns two elements: the estimated association strength and the standard error of the estimate.
Author(s)
William Hoppitt <W.J.E.Hoppitt@leeds.ac.uk> Damien Farine <dfarine@orn.mpg.de>
References
Hoppitt, W. & Farine, D.R. (in prep) Association indices for quantifying social relationships: how to deal with missing observations of individuals or groups.
Examples
# Simulated values (all = 10)
x <- yab <- 10
# Calculate very simple ratio index
vSRI(x,yab)