kernrat: Ratio of two kernel smoothings
Description
Return the ratio of two kernel smoothingsUsage
kernrat(pts1,pts2,poly,h1,h2,nx=20,ny=20,kernel='quartic')
Arguments
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:
- xList of x-coordinates at which the kernel function has been evaluated.
- yList of y-coordinates at which the kernel function has been evaluated.
- zA matrix of dimension
nx by ny containing the ratio of the kernel functions. - hA vector of length 2 containing
h1 and h2 - kernela 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.