Package 'steepness'

Title: Testing Steepness of Dominance Hierarchies
Description: The steepness package computes steepness as a property of dominance hierarchies. Steepness is defined as the absolute slope of the straight line fitted to the normalized David's scores. The normalized David's scores can be obtained on the basis of dyadic dominance indices corrected for chance or by means of proportions of wins. Given an observed sociomatrix, it computes hierarchy's steepness and estimates statistical significance by means of a randomization test.
Authors: David Leiva <[email protected]> & Han de Vries <[email protected]>.
Maintainer: David Leiva <[email protected]>
License: GPL (>= 2)
Version: 0.3-0
Built: 2024-11-16 04:49:13 UTC
Source: https://github.com/cran/steepness

Help Index


Testing Steepness of Dominance Hierarchies

Description

Steepness is a package that computes steepness as a property of dominance hierarchies. Steepness is defined as the absolute slope of the straight line fitted to the normalized David's scores. The normalized David's scores can be obtained on the basis of dyadic dominance indices corrected for chance or from the matrix of win proportions. Given an observed sociomatrix, it computes hierarchy's steepness and estimates statistical significance by means of a randomization test (see de Vries, Stevens and Vervaecke, 2006).

Details

Package: steepness
Version: 0.2-2
Date: 2014-29-09
Depends: >= 3.1.0
License: GPL version 2 or newer

Index:

getDij            Dyadic dominance index corrected for chance -Dij-
getDS             David's scores -DS-
getNormDS         Normalized David's scores -NormDS-
getOrderedMatrix  Ordered matrix according to NormDS values
getPij            Matrix of proportions of wins -Pij-
getStp            Hierarchy's steepness measure -Stp-
getwl             Several win and loss measures at individual level
steeptest         Statistical significance for steepness statistic

Author(s)

David Leiva <[email protected]> & Han de Vries <[email protected]>.

Maintainer: David Leiva <[email protected]>

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

For more information see: getDij, getDS, getNormDS, getOrderedMatrix, getPij, getStp, getwl, steeptest.


Dyadic dominance index corrected for chance -Dij-

Description

Function to obtain matrix of dyadic dominance indices corrected for chance from the observed sociomatrix.

Usage

getDij(X, names=NULL)

Arguments

X

Empirical sociomatrix containing wins-losses frequencies in dyadic encounters.

names

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

Details

getDij is only applied for square matrices in which the set of n actors is also the set of n partners. The matrices must also be numeric.

Value

Dij

Matrix of observed dyadic dominance indices corrected for chance.

Author(s)

David Leiva [email protected] & Han de Vries [email protected].

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

steeptest.

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 <- getDij(X,individuals)

print(res,digits=3)

David's scores -DS-

Description

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

Usage

getDS(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

getDS is obtained by means of the following expression: DS=w1+w2l1l2DS = w1 + w2 - l1 - l2 where w1 is the sum of i's Dij or Pij values (depending on the method specification); w2 is the weighted sum of i‘s dyadic dominance indices corrected for chance or the weighted sum of i’s win proportions; l1 is the sum of i's Dji or Pji values and l2 is the sum of i's dyadic lose indices corrected for chance or the weighted sum of i's lose proportions.

Value

DS

David's scores based on dyadic dominance indices corrected for chance or on win proportions.

Author(s)

David Leiva [email protected] & Han de Vries [email protected].

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, getwl.

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

print(res,digits=3)

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(N1)/2)/NNormDS = (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 [email protected] & Han de Vries [email protected].

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)

Ordered matrix according to NormDS values

Description

Function to order the observed matrix of dyadic dominance encounters according to the individuals' NormDS values.

Usage

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

Arguments

X

Empirical sociomatrix containing wins-losses frequencies in dyadic encounters.

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

getOrderedMatrix is only applied for square matrices in which the set of n actors is also the set of n partners. The matrices must also be numeric.

Value

ordered.matrix

Matrix of observed dyadic dominance encounters ordered according to the individuals' NormDS values.

ordered.names

Vector of individuals' names ordered according to their NormDS values.

order.seq

Sequence used in the order of the matrix of dyadic encounters and the vector of names.

Author(s)

David Leiva [email protected] & Han de Vries [email protected].

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

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")

res <- getOrderedMatrix(X,individuals,method="Dij")$ordered.matrix

print(res,digits=3)

Matrix of win proportions -Pij-

Description

Function to obtain matrix of win proportions from the observed sociomatrix.

Usage

getPij(X, names=NULL)

Arguments

X

Empirical sociomatrix containing wins-losses frequencies in dyadic encounters.

names

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

Details

getPij is only applied for square matrices in which the set of n actors is also the set of n partners. The matrices must also be numeric.

Value

Pij

Matrix of observed win proportions.

Author(s)

David Leiva [email protected] & Han de Vries [email protected].

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

steeptest.

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 <- getPij(X,individuals)

print(res,digits=3)

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 [email protected] & Han de Vries [email protected].

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)

Win-loss measures at individual level

Description

Function to obtain win and loss measures at individual level from the observed sociomatrix.

Usage

getwl(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

By means of the empirical sociomatrix of wins and losses this function computes several win-loss measures at individual level. Specifically, it computes w, weighted.w, l and weighted.l. w is the sum of individuals' dyadic dominances Dij or the sum of proportions of wins Pij by rows, depending on the specification of the method. weighted.w measures is the sum of individuals' Dij or Pij values weighted by the w values of their interactants. l is the sum of individuals' dyadic dominance indices Dij or the sum of individuals' proportions of wins Pij by columns. And finally, weighted.l is the columns sum of individuals' Dij or Pij values weighted by the l values of their interactants. These measures are used when computing David's scores.

Value

The result is a data frame with the following components:

w

Sum of dyadic dominance indices Dij or proportions of wins Pij by rows.

weighted.w

Weighted sum of dyadic dominance indices Dij or proportions of wins Pij.

l

Sum of dyadic dominance indices Dij or proportions of wins Pij by columns.

weighted.l

Weighted sum of dyadic dominance indices Dij or proportions of wins Pij.

Author(s)

David Leiva [email protected] & Han de Vries [email protected].

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

print(res,digits=3)

Statistical significance for steepness of dominance hierarchies statistic

Description

Estimates statistical significance for steepness measure on the basis of dyadic dominance indices corrected for chance Dij or based on proportions of wins Pij.

Usage

steeptest(X, rep, names=NULL, method=c("Dij","Pij"), order=TRUE)

Arguments

X

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

rep

Number of simulations for carrying out the randomization test.

names

Character vector with individuals' names.

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.

order

Logical, if TRUE, results for Dij, DS and NormDS are ordered according to the individuals' NormDS values. TRUE by default.

Details

steeptest estimates statistical significance for steepness measures based on dyadic dominance index corrected for chance Dij or based on the matrix of win proportions Pij, depending on the method specified. This procedure simulates a number of sociomatrices under a uniform distribution by means of callings to C routine steep, then computes steepness based on Dij or Pij. Specifically, it computes normalized David's scores, see getNormDS for more details. Then it computes the steepness measure based on these indices, see getStp. After rep simulations the sampling distribution for the statistic (Stp) is estimated. Then statistical significance is computed as follows when results are shown by means of summary method: p=NS+1/NOS+1p=NS+1/NOS+1 Where NS is computed as:

  1. The number of times that simulated values are greater than or equal to the empirical value, if right-tailed p value is calculated.

  2. And the number of times that simulated values are lower than or equal to the empirical value, if left-tailed p value is calculated.

And NOS represents the number of simulated values.

Value

steeptest returns an object of class steeptest containing the following components:

call

Function call.

names

Character vector with individuals' names.

method

A character string indicating which dyadic dominance measure is used for the computation of David's scores.

rep

Number of simulations for carrying out the randomization test.

matdom

If method is set to be Dij the function returns the matrix of observed dyadic dominance indices corrected for chance. If method is Pij the matrix of proportions of wins is returned as a part of the output.

DS

David's scores based on Dij or Pij, depending on the specification of the method.

NormDS

Normalized David's scores based on dyadic dominance indices corrected for chance or on proportions of wins in dyadic encounters.

Stp

Steepness value based on Normalized David's scores.

interc

Intercept of the fitted line based on Normalized David's scores.

Stpsim

The function provides results of the randomization procedure for the steepness measure based on NormDS.

Author(s)

David Leiva [email protected] & Han de Vries [email protected].

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, 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")

 STP <- steeptest(X, rep=9999, names=individuals, method="Dij", order=TRUE)
 summary(STP)
 plot(STP)