Extract.leverage.ppm: Extract Subset of Leverage Object
Description
Extract a subset of a leverage map,
or extract the leverage values at specified locations.
Usage
## S3 method for class 'leverage.ppm':
[(x, i, ...)
Arguments
x
A leverage object (of class "leverage.ppm")
computed by leverage.ppm.
i
Subset index (passed to [.im).
Either a spatial window (object of class "owin")
or a spatial point pattern (object of class "ppp").
...
Further arguments passed to [.im,
especially the argument drop.
Value
Another object of class "leverage.ppm",
or a vector of numeric values of leverage.
Details
An object of class "leverage.ppm" contains the values of the
leverage function for a point process model, computed by
leverage.ppm.
This function extracts a designated subset of the leverage values,
either as another leverage object, or as a vector of numeric values.
The function [.leverage.ppm is a method for [ for the
class "leverage.ppm". The argument i should be either
a spatial window (object of class"owin")
determining a region where the leverage map is required.
The result will typically be another leverage map
(object of classleverage.ppm).
a spatial point pattern (object of class"ppp")
specifying locations at which the leverage values are required.
The result will be a numeric vector.
The subset operator for images, [.im, is applied to
the leverage map. If this yields a pixel image, then the result of
[.leverage.ppm is another leverage object. Otherwise,
a vector containing the numeric values of leverage is returned.