kernrat {splancs}R Documentation

Ratio of two kernel smoothings

Description

Return the ratio of two kernel smoothings

Usage

kernrat(pts1,pts2,poly,h1,h2,nx=20,ny=20,kernel='quartic')

Arguments

pts1,pts2 Point data sets
poly A polygon data set
h1,h2 The kernel width parameters, h1 for pts1, and h2 for pts2
nx Number of points along the x-axis of the returned grid.
ny Number of points along the y-axis of the returned grid.
kernel Type of kernel function to use. Currently only the quartic kernel is implemented.

Value

A list with the following components:

x List of x-coordinates at which the kernel function has been evaluated.
y List of y-coordinates at which the kernel function has been evaluated.
z A matrix of dimension nx by ny containing the ratio of the kernel functions.
h A vector of length 2 containing h1 and h2
kernel a character string containing the kernel name.

References

Berman M. and Diggle P.J. (1989) Estimating Weighted Integrals of the Second-Order Intensity of Spatial Point Patterns. J. R. Statist Soc B51 81-92; Rowlingson, B. and Diggle, P. 1993 Splancs: spatial point pattern analysis code in S-Plus. Computers and Geosciences, 19, 627-655; the original sources can be accessed at: http://www.maths.lancs.ac.uk/~rowlings/Splancs/. See also Bivand, R. and Gebhardt, A. 2000 Implementing functions for spatial statistical analysis using the R language. Journal of Geographical Systems, 2, 307-317.

See Also

kernel2d, mse2d


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