is.dyad.independent {ergm}

Testing for dyad-independence

Description

These functions test whether an ERGM fit, a formula, or some other object represents a dyad-independent model.

The method for NULL always returns TRUE by convention.

Usage

is.dyad.independent(object, ...)

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

## S3 method for class 'formula'
is.dyad.independent(object, response = NULL, basis = NULL, ...)

## S3 method for class 'ergm_conlist'
is.dyad.independent(object, object.obs = NULL, ...)

## S3 method for class 'ergm'
is.dyad.independent(object, how = c("overall", "terms", "space"), ...)

Arguments

object

The object to be tested for dyadic independence.

...

Unused at this time.

response

Either a character string, a formula, or NULL (the default), to specify the response attributes and whether the ERGM is binary or valued. Interpreted as follows:

NULL

Model simple presence or absence, via a binary ERGM.

character string

The name of the edge attribute whose value is to be modeled. Type of ERGM will be determined by whether the attribute is logical (TRUE/FALSE) for binary or numeric for valued.

a formula

must be of the form NAME~EXPR|TYPE (with | being literal). EXPR is evaluated in the formula's environment with the network's edge attributes accessible as variables. The optional NAME specifies the name of the edge attribute into which the results should be stored, with the default being a concise version of EXPR. Normally, the type of ERGM is determined by whether the result of evaluating EXPR is logical or numeric, but the optional TYPE can be used to override by specifying a scalar of the type involved (e.g., TRUE for binary and 1 for valued).

basis

See ergm.

object.obs

For the ergm_conlist method, the observed data constraint.

how

one of "overall" (the default), "terms", or "space", to specify which aspect of the ERGM is to be tested for dyadic independence.

Details

Dyad independence is determined by checking if all of the constituent parts of the object (formula, ergm terms, constraints, etc.) are flagged as dyad-independent.

Value

TRUE if the model implied by the object is dyad-independent; FALSE otherwise.