Description Usage Arguments References
View source: R/socialnetwork.R
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.
1 | calculateassociations(x, y, ir)
|
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 |
Illian, Moller, Waagepetersen, 2009. Hierarchical spatial point process analysis for a plant community of high biodiversity.Environ. Ecol. Stat. vol 16, pp 389-405
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