ergm: ergm_model – R documentation

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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. Each term is initialized via the InitErgmTerm functions to create a ergm_model object.

Usage

ergm_model(
  formula,
  nw = NULL,
  response = NULL,
  silent = FALSE,
  role = "static",
  ...,
  term.options = list()
)

## S3 method for class 'ergm_model'
c(...)

as.ergm_model(x, ...)

## S3 method for class 'ergm_model'
as.ergm_model(x, ...)

## S3 method for class 'formula'
as.ergm_model(x, ...)

## S3 method for class 'ergm_model'
is.curved(object, ...)

## S3 method for class 'ergm_model'
is.durational(object, ...)

## S3 method for class 'ergm_model'
is.dyad.independent(object, ...)

## S3 method for class 'ergm_model'
nparam(object, canonical = FALSE, offset = NA, byterm = FALSE, ...)

## S3 method for class 'ergm_model'
param_names(object, canonical = FALSE, ...)

Arguments

`formula`	An `ergm()` formula of the form `network ~ model.term(s)` or `~ model.term(s)`.
`nw`	The network of interest; if passed, the LHS of `formula` is ignored. This is the recommended usage.
`response`	Name of the edge attribute whose value is to be modeled in the valued ERGM framework. Defaults to `NULL` for simple presence or absence, modeled via a binary ERGM.
`silent`	logical, whether to print the warning messages from the initialization of each model term.
`role`	A hint about how the model will be used. Used primarily for dynamic network models.
`...`	additional parameters for model formulation
`term.options`	a list of optional settings such as calculation tuning options to be passed to the `InitErgmTerm` functions.
`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.

Value

ergm_model returns an ergm_model object as a list containing:

`coef.names`	a vector of coefficient names
`offset`	a logical vector of whether each term was "offset", i.e. fixed
`terms`	a list of terms and 'term components' initialized by the appropriate `InitErgmTerm.X` function.
`network.stats0`	NULL always??
`etamap`	the theta -> eta mapping as a list returned from <ergm.etamap>

Methods (by generic)

c: A method for concatenating terms of two or more initialized models.
is.curved: Tests whether the model is curved.
is.durational: Test if the model has duration-dependent terms, which call for lasttoggle data structures.
is.dyad.independent: Tests whether the model is dyad-independent.
nparam: Number of parameters of the model.
param_names: Parameter names of the model.

Note

This API is not to be considered fixed and may change between versions. However, an effort will be made to ensure that the methods of this class remain stable.