In binary ERGMs, equal to the number of
pairs of actors \(i\) and \(j\) for which \((i{\rightarrow}j)\)
and \((j{\rightarrow}i)\) both exist. For valued ERGMs, equal to \(\sum_{i<j} m(y_{i,j},y_{j,i})\) ,
where \(m\) is determined by form argument: "min"
for \(\min(y_{i,j},y_{j,i})\) , "nabsdiff" for
\(-|y_{i,j},y_{j,i}|\) , "product" for
\(y_{i,j}y_{j,i}\) , and "geometric" for
\(\sqrt{y_{i,j}}\sqrt{y_{j,i}}\) . See Krivitsky (2012) for a
discussion of these statistics. form="threshold" simply
computes the binary mutuality after
thresholding at threshold .
This term can only be used with directed networks.
# binary: mutual(same=NULL, by=NULL, diff=FALSE, keep=NULL, levels=NULL)# valued: mutual(form="min",threshold=0)
if the optional argument is passed
(see Specifying Vertex attributes and Levels (?nodal_attributes) for details),
only mutual pairs that match on the attribute are counted;
separate counts for each unique matching value can be obtained by using
diff=TRUE with same. Only one of same or by may be used. If both parameters are used, by is
ignored. This paramer is affected by diff.
if the optional argument is passed (see Specifying Vertex attributes and Levels (?nodal_attributes) for details),
then each node is counted separately for each mutual pair in which it
occurs and the counts are tabulated by unique values of the attribute.
This means that the sum of the mutual statistics when by is used
will equal twice the standard mutual statistic. Only one of same or by may be used. If both parameters are used, by is
ignored. This paramer is not affected by diff.
deprecated
which statistics should be kept whenever the mutual term would ordinarily result in multiple statistics. (See Specifying Vertex
attributes and Levels (?nodal_attributes) for details.)
character how to aggregate tie values in a valued ERGM
ergmTerm for index of model terms currently visible to the package.
ergm:::.formatTermKeywords("ergmTerm", "mutual", "subsection")