# model.matrix.mppm

##### Extract Design Matrix of Point Process Model for Several Point Patterns

Given a point process model fitted to a list of point patterns, this function extracts the design matrix.

##### Usage

```
# S3 method for mppm
model.matrix(object, ..., keepNA=TRUE, separate=FALSE)
```

##### Arguments

- object
A point process model fitted to several point patterns. An object of class

`"mppm"`

.- …
Other arguments (such as

`na.action`

) passed to`model.matrix.lm`

.- keepNA
Logical. Determines whether rows containing

`NA`

values will be deleted or retained.- separate
Logical value indicating whether to split the model matrix into sub-matrices corresponding to each of the original point patterns.

##### Details

This command is a method for the generic function
`model.matrix`

. It extracts the design matrix of a
point process model fitted to several point patterns.

The argument `object`

must be a fitted point process model
(object of class `"mppm"`

) produced by the
fitting algorithm `mppm`

). This represents a
point process model that has been fitted
to a list of several point pattern datasets. See `mppm`

for information.

The result is a matrix with one column for every constructed covariate in the model, and one row for every quadrature point.

If `separate=TRUE`

this matrix will be split into
sub-matrices corresponding to the original point patterns,
and the result will be a list containing these matrices.

##### Value

A matrix (or list of matrices). Columns of the matrix are canonical covariates in the model.

##### See Also

##### Examples

```
# NOT RUN {
fit <- mppm(Points ~ Image + x, demohyper)
head(model.matrix(fit))
# matrix with three columns: '(Intercept)', 'x' and 'Image'
# }
```

*Documentation reproduced from package spatstat, version 1.55-1, License: GPL (>= 2)*