R: Check Whether Spatial Logistic Regression Model is Valid

valid.slrm {spatstat.core} | R Documentation

## Check Whether Spatial Logistic Regression Model is Valid

### Description

Determines whether a fitted spatial logistic regression model is a well-defined model.

### Usage

      ## S3 method for class 'slrm'
    valid(object, warn=TRUE, ...)

### Arguments

`object` | Fitted spatial logistic regression model (object of class `"slrm"`).
`warn` | Logical value indicating whether to issue a warning if the validity of the model cannot be checked (due to unavailability of the required code).
`...` | Ignored.

### Details

This is a method for the generic function `valid` for spatial logistic regression models (class `"slrm"`).

In a model fitted by `slrm`, some of the fitted coefficients may be `NA` or infinite values. This can occur if the data are not adequate for estimation of the model parameters. The model is said to be unidentifiable or confounded.

The function `valid.slrm` checks whether the fitted coefficients of `object` specify a well-defined model. It returns `TRUE` if the model is well-defined, and `FALSE` otherwise.

Use the function `emend.slrm` to force the fitted model to be valid.

### Value

A logical value, or `NA`.

### Author(s)

Adrian Baddeley Adrian.Baddeley@curtin.edu.au, Rolf Turner r.turner@auckland.ac.nz and Ege Rubak rubak@math.aau.dk.

### See Also

`slrm`, `emend.slrm`

### Examples

       fit1 <- slrm(cells ~ x)
       valid(fit1)
       fit2 <- slrm(cells ~ x + I(x))
       valid(fit2)

[Package spatstat.core version 2.4-4 Index]