XploRe Help : SPPPinit

Keywords - Function groups - @ A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Library:	spatial
See also:	SPPPinitrandom SPPPsetregion SPPPgetregion SPPPkfn SPPPpsim SPPPstrauss SPPPssi SPPPkenvl SPPPkaver

Quantlet:		SPPPinit
Description:		creates a point process object and calls SPPPsetregion to set the rectangular spatial domain

Reference(s):

Venables, W. N., Ripley, B. D. (1999): Modern Applied Statistics with S-Plus, Third Edition, Springer, New York

Link:

Tutorial: Spatial statistics

Usage:	`res = SPPPinit(pp, xl, xu, yl, yu, fac)`
Input:
	`pp`	n x 2 matrix, x and y coordinates of locations
	`xl`	scalar, lower limit in x-direction of the domain rectangle
	`xu`	scalar, upper limit in x-direction of the domain rectangle
	`yl`	scalar, lower limit in y-direction of the domain rectangle
	`yu`	scalar, upper limit in y-direction of the domain rectangle
	`fac`	scalar, used to rescale all coordinates, i.e., to divide all coordinates by fac
Output:
	`res`	list, consisting of components pp, area and type:
	`res.pp`	n x 2 matrix, input matrix pp scaled by fac
	`res.area`	4 x 1 vector, consisting of xl, xu, yl, and yu, all scaled by fac
	`res.type`	string, "PP"

Note:

C-Code from Venables, Ripley (1999) forms the basis of this quantlet. Also check this reference for more details.

Example:

; loads the spatial statistics library library("spatial") ; reads a spatial data set pines = read("pines.dat") ; initializes a point process pinesobj = SPPPinit(pines, 0, 96, 0, 100, 10) pinesobj

Result:

A point process object suitable for use in SPPPkfn:

Contents of pinesobj.pp
[ 1,]      0.1      9.9
[ 2,]      0.1      7.2
[ 3,]      0.2      6.2
[ 4,]      0.2      8.4
[ 5,]      0.7      4.5
...
[70,]      9.5      4.6
[71,]      9.5      6.2

Contents of pinesobj.area
[1,]        0
[2,]      9.6
[3,]        0
[4,]       10

Contents of pinesobj.type
[1,] "PP"

Author: J. Symanzik, 20000725 license MD*Tech