assocInd (version 1.0.1)

vSRI: 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

Value

Returns two elements: the estimated association strength and the standard error of the estimate.

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).

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)