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(object, nw = NULL, ..., formula = NULL)
# S3 method for formula
ergm_model(object, nw = NULL, ...)
# S3 method for term_list
ergm_model(
  object,
  nw = NULL,
  silent = FALSE,
  ...,
  term.options = list(),
  env = globalenv(),
  extra.aux = list(),
  offset.decorate = TRUE,
  terms.only = FALSE
)
# S3 method for ergm_model
ergm_model(
  object,
  nw,
  ...,
  env = globalenv(),
  extra.aux = list(),
  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, byterm = FALSE, ..., ignore_aux = TRUE)
# 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, ...)
# S3 method for ergm_model
param_names(object, canonical = FALSE, ...) <- value

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>
term.options: the term options used to initialize the terms
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

object: An ergm_model object.
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.
...: additional parameters for model formulation
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.
silent: logical, whether to print the warning messages from the initialization of each model term.
term.options: A list of additional arguments to be passed to term initializers. See ? term.options.
env: a throwaway argument needed to prevent conflicts with some usages of ergm_model. The initialization environment is always taken from the formula.
extra.aux: a list of auxiliary request formulas required elsewhere; if named, the resulting slots.extra.aux will also be named.
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.
byterm: Whether to return the result for each term individually.
ignore_aux: A flag to specify whether a dyad-dependent auxiliary should make the model dyad-dependent or should be ignored.
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.
value: For param_names<-(), either a character vector equal in length to the number of parameters of the specified type (though recycled as needed), or a list of two character vectors, one for non-canonical, the other for canonical, in which case canonical= will be ignored. NA elements preserve existing name.

Methods (by class)

ergm_model(formula): a method for formula: extracts the network and the term_list and passes it on to the next method.
ergm_model(term_list): a method for term_list: nw= is mandatory; initializes the terms in the list and passes it on to the next method.
ergm_model(ergm_model): a method for term_list: nw= is mandatory, and term.options= must be a part of the ergm_model object, with ... ignored; (re)generates the auxiliaries and, the eta map, and the unique ID; and decorates offsets.

Methods (by generic)