R: Convert Leverage Object to Function of Coordinates

as.function.leverage.ppm {spatstat.core} | R Documentation

## Convert Leverage Object to Function of Coordinates

### Description

Converts an object of class `"leverage.ppm"` to a function of the x and y coordinates.

### Usage

     ## S3 method for class 'leverage.ppm'
    as.function(x, ...)

### Arguments

`x` | Object of class `"leverage.ppm"` produced by `leverage.ppm`.
`...` | Ignored.

### Details

An object of class `"leverage.ppm"` represents the leverage function of a fitted point process model. This command converts the object to a `function(x,y)` where the arguments `x` and `y` are (vectors of) spatial coordinates. This function returns the leverage values at the specified locations (calculated by referring to the nearest location where the leverage has been computed).

### Value

A function in the R language, also belonging to the class `"funxy"`.

### 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

`as.im.leverage.ppm`

### Examples

      X <- rpoispp(function(x,y) { exp(3+3*x) })
      fit <- ppm(X ~x+y)
      lev <- leverage(fit)
      f <- as.function(lev)

      f(0.2, 0.3)  # evaluate at (x,y) coordinates
      y <- f(X)    # evaluate at a point pattern

[Package spatstat.core version 2.0-0 Index]