getStp {steepness}

Steepness measure of dominance hierarchies -Stp-

Description

Function to obtain hierarchy's steepness measure from the observed sociomatrix.

Usage

   getStp(X, method=c("Dij","Pij"))

Arguments

X

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

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

getStp is the absolute value of the slope of the best-fitted line between the normalized David's scores and the rank dominance in a decreasing order. The regression is obtained by Ordinary Least Squares method.

Value

getStp

Steepness measure based on dyadic dominance indices corrected for chance or based on the matrix of win proportions, depending on the method specified.

Author(s)

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

References

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, getNormDS.

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")

print(getStp(X,method="Dij"),digits=3)