ergm (version 4.6.0)

ergm_model: Internal representation of an ergm network model

Description

These methods are generally not called directly by users, but may be employed by other depending packages. ergm_model constructs it from a formula or a term list. Each term is initialized via the InitErgmTerm functions to create a ergm_model object.

Usage

ergm_model(
  formula,
  nw = NULL,
  silent = FALSE,
  ...,
  term.options = list(),
  extra.aux = list(),
  env = globalenv(),
  offset.decorate = TRUE,
  terms.only = FALSE
)
# S3 method for ergm_model
c(...)
as.ergm_model(x, ...)
# S3 method for ergm_model
as.ergm_model(x, ...)
# S3 method for formula
as.ergm_model(x, ...)
# S3 method for ergm_model
is.curved(object, ...)
# S3 method for ergm_model
is.dyad.independent(object, ...)
# S3 method for ergm_model
nparam(object, canonical = FALSE, offset = NA, byterm = FALSE, ...)
# S3 method for ergm_model
param_names(object, canonical = FALSE, offset = NA, ...)

Value

ergm_model returns an ergm_model object as a list containing:

terms

a list of terms and 'term components' initialized by the appropriate InitErgmTerm.X function.

etamap

the theta -> eta mapping as a list returned from <ergm.etamap>

uid

a string generated with the model, concatenating the UNIX time (Sys.time()) to maximum available precision, process ID (Sys.getpid()), and a counter that starts at -.Machine$integer.max and increments by 1 with every call; different models are, generally, guaranteed to have different strings, but identical models are not guaranteed to have the same string

Arguments

formula

An ergm() formula of the form network ~ model.term(s) or ~ model.term(s) or a term_list object, typically constructed from a formula's LHS.

nw

The network of interest, optionally instrumented with ergm_preprocess_response() to have a response attribute specification; if passed, the LHS of formula is ignored. This is the recommended usage.

silent

logical, whether to print the warning messages from the initialization of each model term.

...

additional parameters for model formulation

term.options

A list of additional arguments to be passed to term initializers. See ? term.options.

extra.aux

a list of auxiliary request formulas required elsewhere; if named, the resulting slots.extra.aux will also be named.

env

a throwaway argument needed to prevent conflicts with some usages of ergm_model. The initialization environment is always taken from the formula.

offset.decorate

logical; whether offset coefficient and parameter names should be enclosed in "offset()".

terms.only

logical; whether auxiliaries, eta map, and UID constructions should be skipped. This is useful for submodels.

x

object to be converted to an ergm_model.

object

An ergm_model object.

canonical

Whether the canonical (eta) parameters or the curved (theta) parameters are used.

offset

If NA (the default), all model terms are counted; if TRUE, only offset terms are counted; and if FALSE, offset terms are skipped.

byterm

Whether to return a vector of the numbers of coefficients for each term.

Methods (by generic)

• c(ergm_model): A method for concatenating terms of two or more initialized models.

• is.curved(ergm_model): Tests whether the model is curved.

• is.dyad.independent(ergm_model): Tests whether the model is dyad-independent.

• nparam(ergm_model): Number of parameters of the model.

• param_names(ergm_model): Parameter names of the model.

See Also

summary.ergm_model(), ergm_preprocess_response()