ei {netseg}

Krackhard and Stern's E-I index

Description

An index proposed by Krackhard and Stern (1988) to capture relative prevalence of between- and within-group ties. From that perspective it can be interpreted as a measure of network segregation.

Usage

ei(object, ...)

## S3 method for class 'table'
ei(object, ...)

## S3 method for class 'igraph'
ei(
  object,
  vattr,
  directed = is.directed(object),
  loops = any(is.loop(object)),
  ...
)

## Default S3 method:
ei(object, ...)

Arguments

object

R object, see Details for available methods

...

other arguments passed to/from other methods

vattr

character scalar or vector of length equal to the size of object, vertex attribute for which mixing matrix is to be computed

directed

logical whether the network is directed

loops

logical, whether loops are allowed

Details

If object is a table it is interpreted as a mixing matrix. Two-dimensional table is interpreted as a contact layer. Three-dimensional table is interpreted as a full mixing matrix m_{ghy} cross-classyfying all dyads, in which g and h correspond to group membership of ego and alter respectively. Layers y=1 and y=2 are assumed to be non-contact and contact layers respectively.

If object is of class "igraph" it is required to supply vattr with the name of the vertex attribute to calculate intermediate mixing matrix.

Value

Numerical value of the E-I index.

References

Krackhardt, D., & Stern, R. N. (1988). Informal networks and organizational crises: An experimental simulation. Social Psychology Quarterly, 123-140.

See Also

Other segregation measures: assort(), coleman(), freeman(), gamix(), orwg(), smi(), ssi()

Examples

ei(WhiteKinship, "gender")