ddf

Purpose This function calculates the directional distribution of points defined in [1] of a point process returning the distributions in matrix T.
Synopsis: T = ddf(H, r1, r2)
T = ddf(H, r1, r2, N)
T = ddf(H, r1, r2, N, str)
[T, a] = ddf(H, ...)
Description: T=ddf(H, r1, r2) calculates the directional distribution T of points in B, type uint8, such that r1<=|x-y|<r2.

T=ddf(H, r1, r2, N) specifies the number of angular bins as N, (default=72).

T=ddf(H, r1, r2, N, str), when str="cluster", ddf calculates the direction distribution of daughter points about a parent point.

[T, a]=ddf(H, ...) returns the center angle for each bin of T in a.
See Also: nnt
Reference: [1] J. Ohser, D. Stoyan, On the second-order and orientation analysis of planar stationary point processes, Biometrics Journal, Vol. 23, 1981.
Author: Daniel Leo Lau, Copyright August 18, 1997.