R: Extract Design Matrix of Point Process Model for Several...

model.matrix.mppm {spatstat} | R Documentation

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

### Description

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

### Usage

       ## S3 method for class '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.

### 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

`model.matrix`, `mppm`.

### Examples

       fit <- mppm(Points ~ Image + x, demohyper)
       head(model.matrix(fit))
       # matrix with three columns: '(Intercept)', 'x' and 'Image'

[Package spatstat version 1.63-3 Index]