Kernel Smoothing of Line Segment Pattern (original) (raw)

density.psp: Kernel Smoothing of Line Segment Pattern

View source: R/density.psp.R

density.psp R Documentation

Description

Compute a kernel smoothed intensity function from a line segment pattern.

Usage

S3 method for class 'psp'

density(x, sigma, ..., weights=NULL, edge=TRUE, method=c("FFT", "C", "interpreted"), at=NULL)

Arguments

x Line segment pattern (object of class "psp") to be smoothed.
sigma Standard deviation of isotropic Gaussian smoothing kernel.
... Extra arguments, including arguments passed to as.maskto determine the resolution of the resulting image.
weights Optional. Numerical weights for each line segment. A numeric vector, of length equal to the number of segments inx.
edge Logical flag indicating whether to apply edge correction.
method Character string (partially matched) specifying the method of computation. Option "FFT" is the fastest, while"C" is the most accurate.
at Optional. An object specifying the locations where density values should be computed. Either a window (object of class "owin") or a point pattern (object of class "ppp" or "lpp").

Details

This is the method for the generic function densityfor the class "psp" (line segment patterns).

A kernel estimate of the intensity of the line segment pattern is computed. The result is the convolution of the isotropic Gaussian kernel, of standard deviation sigma, with the line segments. The result is computed as follows:

If edge=TRUE this result is adjusted for edge effects by dividing it by the convolution of the same Gaussian kernel with the observation window.

If weights are given, then the contribution from line segmenti is multiplied by the value of weights[i].

If the argument at is given, then it specifies the locations where density values should be computed.

Value

A pixel image (object of class "im") or a numeric vector.

Author(s)

\spatstatAuthors

.

See Also

psp.object,im.object,density

Examples

L <- psp(runif(20),runif(20),runif(20),runif(20), window=owin()) D <- density(L, sigma=0.03) plot(D, main="density(L)") plot(L, add=TRUE)

spatstat.core documentation built on May 18, 2022, 9:05 a.m.