calculateassociations: Generates social network based on xy spatial coordinates of...

In SocialNetworks: Generates social networks based on distance.

Description

This method uses the pairwise distances between each pair of individuals. For a spatial point pattern X, the association of individual j on individual i, Aij, is calculated using the distances between points X_i and X_j using a smooth interaction function first introduced by Illian (2009). If d represents the distance between points X_i and X_j, and the interaction radius for individual i is R_i, then the association of j on i is calculated as: ((1-(d/R_i)^2))^2 if d>0 and d<=R_i, and 0 otherwise. This function has been described as a smooth interaction function because the value of the association calculated decreases smoothly as a function of distance. This is in contrast to associations calcuated using a binary function where the association =1 if d<=R and 0 otherwise. Such a function is based on the assumption that the association is constant (1) at all distances less than R_i, and 0 for distances greater than R_i. The figure below shows a plot of both functions (the binary interaction function is represented by the dotted line) for an example where R=1.

Usage

calculateassociations(x, y, ir)

Arguments

x	a list of x coordinates for all the individuals
y	a list of y coordinates for all the individuals
ir	a list of interaction radii for all the individuals

References

Illian, Moller, Waagepetersen, 2009. Hierarchical spatial point process analysis for a plant community of high biodiversity.Environ. Ecol. Stat. vol 16, pp 389-405

SocialNetworks documentation built on May 2, 2019, 1:06 p.m.