fry_ellipsoids: Fit second order intensity ellipses or ellipsoids

In antiphon/Kdirectional: Analysis of anisotropy in point patterns using second order statistics

Fit second order intensity ellipses or ellipsoids

Description

Fit second order intensity ellipses or ellipsoids

Usage

fry_ellipsoids(
  x,
  nvec = 1:5,
  r_adjust = 1,
  nangles,
  eps = 0,
  cylindric = FALSE,
  double = FALSE,
  border = TRUE,
  origin = TRUE,
  verbose = FALSE,
  keep_data = TRUE,
  double2 = FALSE,
  data,
  ALS = FALSE,
  ...
)

Arguments

x	point pattern
nvec	which jumps to consider
r_adjust	consider only fry points with length r_adjust*max(window side)
nangles	If 3d, number of refinements (def=2), in 2d def=20 sectors.
eps	add to the sector angle. Results in smoothing if >0 (default=0).
cylindric	Use a cylinder instead of a sector
double	Should we use both directions of a pair
border	Should border effects be cancelled by minus sampling, if TRUE, "double" ignored.
origin	Constrain the ellipses' centers to origo.
keep_data	Keep the data for each ellipsoid, inside each ellipsoids? Helps with averaging.
data	The vectors to which fit ellipses. Default is missing, and we compute Fry-points.
ALS	(false) Use ALS to refine OLS fits.

Details

First we compute the Fry-points, then we look at the Fry-points in many directions from origin and find the kth point in each, then we fit ellipsoids to the kth-points.

antiphon/Kdirectional documentation built on Feb. 13, 2023, 6:26 a.m.