R: Checks an ergm Object for Degeneracy

ergm.degeneracy {ergm} | R Documentation

## Checks an ergm Object for Degeneracy

### Description

The `ergm.degeneracy` function checks a given ergm object for degeneracy by computing and returning the instability value of the model and the value of the log-likelihood function at the maximized theta values

### Usage

    ergm.degeneracy(object, control = object$control,
                    fast = TRUE, test.only = FALSE,
                    verbose = FALSE)

### Arguments

`object` | an `ergm` object
`control` | the list of control parameters as returned by `control.ergm`; default=control.ergm()
`fast` | whether the degeneracy check should be "fast", i.e to sample changeobs(?) when there are > 100, rather than use all changeobs; default=TRUE
`test.only` | whether to silence printing of the model instability calculation (T or F); this parameter is ignored if the instability > 1; default=FALSE
`verbose` | whether to print a notification when 'object' is deemed degenerate (T or F); default=FALSE

### Value

returns the original ergm object with 2 additional components:

- degeneracy.value: the instability of the model

- degeneracy.type : a 2-element vector containing

  - loglikelihood: the value of the log-likelihood function corresponding to 'theta'; if degenerate, this is a vector of Inf

  - theta : the vector of theta values found through maximixing the log- likelihood; if degenerate, this is 'guess'

[Package ergm version 3.8.0 Index]