# anova.lppm

##### ANOVA for Fitted Point Process Models on Linear Network

Performs analysis of deviance for two or more fitted point process models on a linear network.

##### Usage

```
## S3 method for class 'lppm':
anova(object, \dots, test=NULL)
```

##### Arguments

- object
- A fitted point process model on a linear network
(object of class
`"lppm"`

). - ...
- One or more fitted point process models on the same linear network.
- test
- Character string, partially matching one of
`"Chisq"`

,`"F"`

or`"Cp"`

.

##### Details

This is a method for `anova`

for
fitted point process models on a linear network
(objects of class `"lppm"`

,
usually generated by the model-fitting function `lppm`

).

If the fitted models are all Poisson point processes,
then this function performs an Analysis of Deviance of
the fitted models. The output shows the deviance differences
(i.e. 2 times log likelihood ratio),
the difference in degrees of freedom, and (if `test="Chi"`

)
the two-sided p-values for the chi-squared tests. Their interpretation
is very similar to that in `anova.glm`

.

If some of the fitted models are *not* Poisson point processes,
then the deviance difference is replaced by the
adjusted composite likelihood ratio (Pace et al, 2011;
Baddeley et al, 2014).

##### Value

- An object of class
`"anova"`

, or`NULL`

.

##### References

Ang, Q.W. (2010)
*Statistical methodology for events on a network*.
Master's thesis, School of Mathematics and Statistics, University of
Western Australia.
Ang, Q.W., Baddeley, A. and Nair, G. (2012)
Geometrically corrected second-order analysis of
events on a linear network, with applications to
ecology and criminology.
*Scandinavian Journal of Statistics* **39**, 591--617.

Baddeley, A., Turner, R. and Rubak, E. (2014) Adjusted composite likelihood ratio test for Gibbs point processes. Submitted for publication.

McSwiggan, G., Nair, M.G. and Baddeley, A. (2012) Fitting Poisson point process models to events on a linear network. Manuscript in preparation.

Pace, L., Salvan, A. and Sartori, N. (2011)
Adjusting composite likelihood ratio statistics.
*Statistica Sinica* **21**, 129--148.

##### See Also

##### Examples

```
example(lpp)
mod0 <- lppm(X, ~1)
modx <- lppm(X, ~x)
anova(mod0, modx, test="Chi")
```

*Documentation reproduced from package spatstat, version 1.42-2, License: GPL (>= 2)*