flipped.triangles: Determine indices of triangles that are flipped

In retistruct: Retinal Reconstruction Program

Description

In the projection of points onto the sphere, some triangles maybe flipped, i.e. in the wrong orientation. This functions determines which triangles are flipped by computing the vector pointing to the centre of each triangle and comparing this direction to vector product of two sides of the triangle.

Usage

flipped.triangles(Ps, Tt, R = 1)

Arguments

Ps	N-by-2 matrix with columns containing latitudes (phi) and longitudes (lambda) of N points
Tt	Triangulation of points
R	Radius of sphere

Value

List containing:

flipped	Indices of in rows of Tt of flipped triangles.
cents	Vectors of centres.
areas	Areas of triangles.

Author(s)

David Sterratt

retistruct documentation built on April 4, 2020, 5:08 p.m.