GLECI {assocInd}R Documentation

The Group Location Error Corrected Index

Description

Calculates the Group Location Error Corrected Index

Usage

GLECI(x, Ya, Yb, Yab, Ynull, w)

Arguments

x

Number of times individuals a and b were observed together

Ya

Number of times individual a was observed without b

Yb

Number of times individual b was observed without a

Yab

Number of times individuals a and b were observed at the same time but not associating

Ynull

Number of times neither a or b were observed

w

The correction term w (see details)

Details

The GLECI calculates the probability that two individuals are observed together given that one has been seen, correcting for group location error (missing entire groups during a sampling period). This index can be used if prior information is available on the observation probability of finding groups, where the correction factor w is based on calibration data suggesting that failing to observe a group containing both a and b when they are together is w times more (w > 0) or less (w < 0) likely than failing to observe both the group containing a and the group containing b when a and b are apart.

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
	x <- ya <- yb <- yab <- 10
	ynull <- 0
	
	# Set w (here make the GLECI equal to the SRI)
	w <- 1.0

	# Calculate the group location error corrected index
	GLECI(x,ya,yb,yab,ynull,w)
	

[Package assocInd version 1.0.1 Index]