getNormDS {steepness}

Normalized David's scores -NormDS-

Description

Function to obtain normalized David's scores from the observed sociomatrix.

Usage

   getNormDS(X, names=NULL, method=c("Dij","Pij"))

Arguments

X

Empirical sociomatrix containing wins-losses frequencies in dyadic encounters. The matrix must be square and numeric.

names

Character vector with the names of individuals. This vector is NULL by default

method

A character string indicating which dyadic dominance measure is to be used for the computation of David's scores. One of "Dij" or "Pij", can be abbreviated.

Details

getNormDS is obtained by means of the following expression: NormDS = (DS + N(N-1)/2)/N

Value

NormDS

Normalized David's scores based on dyadic dominance indices corrected for chance or based on the win proportions, depending on the method specified.

Author(s)

David Leiva [e-mail] & Han de Vries [e-mail].

References

David, H. A. (1988). The Method of Paired Comparisons. London: C. Griffin.

de Vries, H., Stevens, J. M. G., & Vervaecke, H. (2006). Measuring and testing the steepness of dominance hierarchies. Animal Behaviour, 71, 585-592.

See Also

getDij, getPij, getDS.

Examples

##############################################################################
###               Example taken from Vervaecke et al. (2007):              ###
##############################################################################

X <- matrix(c(0,58,50,61,32,37,29,39,25,8,0,22,22,9,27,20,10,48,
              3,3,0,19,29,12,13,19,8,5,8,9,0,33,38,35,32,57,
              4,7,9,1,0,28,26,16,23,4,3,0,0,6,0,7,6,12,
              2,0,4,1,4,4,0,5,3,0,2,1,1,5,8,3,0,10,3,1,3,0,0,4,1,2,0),
              nrow=9,byrow=TRUE)

individuals <- c("V","VS","B","FJ","PR","VB","TOR","MU","ZV")

res <- getNormDS(X,names=individuals,method="Dij")

print(res,digits=3)