R: Geometrically weighted dyadwise shared partner distribution...

dgwdspL-ergmTerm {ergm.multi}

R Documentation

Geometrically weighted dyadwise shared partner distribution on layers

Description

This term adds one network statistic to the model equal to the geometrically weighted dyadwise shared partner distribution with decay parameter. Note that the GWDSP statistic is equal to the sum of GWNSP plus GWESP. For a directed network, multiple shared partner definitions are possible.

gdwdspL and dgwdspL are aliases for consistency with ergm.

Usage

# binary: dgwdspL(decay, fixed=FALSE, cutoff=30, type="OTP",
#                 Ls.path=NULL, L.in_order=FALSE)

# binary: gwdspL(decay, fixed=FALSE, cutoff=30, type="OTP",
#                Ls.path=NULL, L.in_order=FALSE)

Arguments

`decay`	nonnegative decay parameter for the shared partner or selected directed analogue count; required if `fixed=TRUE` and ignored with a warning otherwise.
`fixed`	optional argument indicating whether the `decay` parameter is fixed at the given value, or is to be fit as a curved exponential-family model (see Hunter and Handcock, 2006). The default is `FALSE` , which means the scale parameter is not fixed and thus the model is a curved exponential family.
`cutoff`	This optional argument sets the number of underlying DSP terms to use in computing the statistics when `fixed=FALSE`, in order to reduce the computational burden. Its default value can also be controlled by the `gw.cutoff` term option control parameter. (See `?control.ergm`.)
`type`	A string indicating the type of shared partner or path to be considered for directed networks: `"OTP"` (default for directed), `"ITP"`, `"RTP"`, `"OSP"`, and `"ISP"`; has no effect for undirected. See the section below on Shared partner types for details.
`Ls.path`, `L.in_order`	a vector of one or two formulas `Ls.path` provides the Layer Logic (c.f. Layer Logic section in the `Layer()` documentation) specifications for the ties of the 2-path or the shared partnership. (If only one formula is given the layers are assumed to be the same.) If `L.in_order==TRUE` , the first tie of the two-path must be the first element of `Ls.path` and the second must be the second; otherwise, any ordering counts, provided there is exactly one of each. (For types `"OSP"` and `"ISP"` , the first tie is considered to be the one incident on the tail of the base tie.)

Shared partner types

While there is only one shared partner configuration in the undirected case, nine distinct configurations are possible for directed graphs, selected using the type argument. Currently, terms may be defined with respect to five of these configurations; they are defined here as follows (using terminology from Butts (2008) and the relevent package):

Outgoing Two-path ("OTP"): vertex k is an OTP shared partner of ordered pair (i,j) iff i \to k \to j. Also known as "transitive shared partner".
Incoming Two-path ("ITP"): vertex k is an ITP shared partner of ordered pair (i,j) iff j \to k \to i. Also known as "cyclical shared partner"
Reciprocated Two-path ("RTP"): vertex k is an RTP shared partner of ordered pair (i,j) iff i \leftrightarrow k \leftrightarrow j.
Outgoing Shared Partner ("OSP"): vertex k is an OSP shared partner of ordered pair (i,j) iff i \to k, j \to k.
Incoming Shared Partner ("ISP"): vertex k is an ISP shared partner of ordered pair (i,j) iff k \to i, k \to j. By default, outgoing two-paths ("OTP") are calculated. Note that Robins et al. (2009) define closely related statistics to several of the above, using slightly different terminology.

Note

This term takes an additional term option (see options?ergm), cache.sp, controlling whether the implementation will cache the number of shared partners for each dyad in the network; this is usually enabled by default.