allstats.sphwin: Calculate four standard summary functions of a point pattern

In baddstats/spherstat: Spatial Point Pattern Analysis, Geometry and Trigonometry for the Sphere

Calculate four standard summary functions of a point pattern

Description

Calculates the F, G, J, and K summary functions for a point pattern on a (subset of a) sphere. Returns them as a function array (of class "fasp", see fasp.object).

Usage

allstats.sphwin(X, ..., dataname=NULL, verbose=FALSE)

Arguments

X	The observed point pattern, from which estimates of F(r), G(r), J(r) and K(r) will be computed. An object of class "sp2" or "sp3", or a 2 or 3 column matrix giving the locations of points in spherical coordinates.
...	Optional arguments, passed to the summary functions Fsphere, Gsphere, Jsphere, and Ksphere.
dataname	A character string giving an optional (alternative) name for the point pattern.
verbose	A logical value; if TRUE, progress reports are printed during calculation.

Details

This computes four standard summary statistics for a point pattern: the empty space function F(r), nearest neighbour distance distribution function G(r), van Lieshout-Baddeley function J(r) and Ripley's function K(r). The real work is done by Fsphere, Gsphere, Jsphere, and Ksphere, respectively. Consult the help files for these functions for further information about the statistical interpretation of F, G, J and K. If verbose is TRUE, then “progress reports” (just indications of completion) are printed out when the calculations are finished for each of the four function types. The overall title of the array of four functions (for plotting by plot.fasp) will be formed from the argument dataname. If this is not given, it defaults to the expression for X given in the call to allstats.sphwin.

Value

A list of length 4 containing the F, G, J and K functions respectively.

The list can be plotted directly using plot (which dispatches to plot.solist).

Each list entry retains the format of the output of the relevant estimating routine Fsphere, Gsphere, Jsphere, or Ksphere. Thus each entry in the list is a function value table (object of class "fv", see fv.object).

Note

1. Sizeable amounts of memory may be needed during the calculation

2. This function is the analogue for point processes on the sphere of the function allstats in spatstat, which is the corresponding function for point processes in R^2. Indeed, almost all of the elements of the code for allstats.sphwin and much of the help page have been taken from allstats with the permission of A. J. Baddeley. This enables the code to be highly efficient and give corresponding output to, and for the information on this help page to be consistent with that for the function allstats. It is hoped that this will minimise or remove any confusion for users of both spatstat and spherstat.

Author(s)

Adrian Baddeley <email: [e-mail]>, Rolf Turner and Tom Lawrence <email:[e-mail]>.

See Also

Fsphere, Gsphere, link{Jsphere}, Ksphere, allstats, plot.solist, plot.fv, fv.object.

Examples

sph <- sphwin(type="sphere")
sph.pp <- rpoispp.sphwin(win=sph, lambda=10)
sph.all <- allstats.sphwin(sph.pp)

baddstats/spherstat documentation built on Feb. 6, 2023, 1:45 a.m.