Sample points Roughly Uniformly on the surface of an ellipsoid, 2D or 3D

Usage

rellipsoid(n, axes = c(1, 1, 1), center, noise.sd = 0, R = NULL, pieces = 1000)

Arguments

axes: vector giving the semi-axis lengths
center: center vector, c(x,y) or c(x,y,z)
noise.sd: noise sd, 0=no noise
R: rotation matrix
pieces: Number of pieces to divide the surface into. See details.

Details

Sampling is done by first sampling uniformly on the surface of a sphere and then transforming with the ellipsoid axes. Corrections:

* 2D: The sampling weights are set to piecewise linear approximation of the ellipse surface integral, the resolution of which is controlled by 'pieces'. * 3D: No weighting at the moment, so very biased for elongated ellipsoids.

Additional nD Gaussian noise can be added by setting `noise.sd`>0.