XploRe Help : SPPPkfn

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:	SPPPinit SPPPinitrandom SPPPsetregion SPPPgetregion SPPPpsim SPPPstrauss SPPPssi SPPPkenvl SPPPkaver

Quantlet:		SPPPkfn
Description:		Computes K-fn of a point pattern. Actually, it computes L = sqrt(K / pi). Note that SPPPinit or SPPPsetregion must have been called before.

Reference(s):

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

Link:

Spatial statistics tutorial

Usage:	`ppkfn = SPPPkfn (pp, fs, k)`
Input:
	`pp`	list - (of type "PP") calculated by SPPPinit
	`fs`	scalar - full scale of the plot
	`k`	scalar - number of regularly spaced distances in (0, fs)
Output:
	`res`	list - consisting of components x, y, k, dmin, lm --
	`x`	n x 1 - vector of distances
	`y`	n x 1 - vector of L-fn values
	`k`	scalar - number of distances returned (which may be less than k if fs is too large)
	`dmin`	scalar - minimum distance between pair of points
	`lm`	scalar - maximum deviation from L(t) = t

Note:

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

Example:

; load the spatial statistics library library ("spatial") ; read a spatial data set pines = read ("pines.dat") ; initialize a point process pinesobj = SPPPinit (pines, 0, 96, 0, 100, 10) ; calculate K-fn in interval (0, 5), split into 100 segments ppkfn = SPPPkfn (pinesobj, 5, 100)

Result:


Returns the L-fn for a point pattern, including some of

its major characteristics.

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

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

Author: Juergen Symanzik, 000725