linearK
Linear K Function
Computes an estimate of the linear \(K\) function for a point pattern on a linear network.
- Keywords
- spatial, nonparametric
Usage
linearK(X, r=NULL, ..., correction="Ang", ratio=FALSE)Arguments
- X
Point pattern on linear network (object of class
"lpp").- r
Optional. Numeric vector of values of the function argument \(r\). There is a sensible default.
- …
Ignored.
- correction
Geometry correction. Either
"none"or"Ang". See Details.- ratio
Logical. If
TRUE, the numerator and denominator of the estimate will also be saved, for use in analysing replicated point patterns.
Details
This command computes the linear \(K\) function from point pattern data on a linear network.
If correction="none", the calculations do not include
any correction for the geometry of the linear network. The result is the
network \(K\) function as defined by Okabe and Yamada (2001).
If correction="Ang", the pair counts are weighted using
Ang's correction (Ang, 2010; Ang et al, 2012).
Value
Function value table (object of class "fv").
References
Ang, Q.W. (2010) Statistical methodology for spatial point patterns on a linear network. MSc thesis, 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.
Okabe, A. and Yamada, I. (2001) The K-function method on a network and its computational implementation. Geographical Analysis 33, 271-290.
See Also
Examples
# NOT RUN {
data(simplenet)
X <- rpoislpp(5, simplenet)
linearK(X)
linearK(X, correction="none")
# }