TETRAHEDRONVOLUME Signed volume of a tetrahedron.

   VOL = tetrahedronVolume(TETRA)
   Comptues the siged volume of the tetrahedron TETRA defined by a 4-by-4
   array representing the polyhedron vertices.

   Example
     vi = [0 0 0;1 0 0;0 1 0;0 0 1];
     tetrahedronVolume(vi)
     ans = 
         0.1667

     [V F] = createTetrahedron;
     tetrahedronVolume(V)
     ans = 
         -.3333

   See also
   meshes3d, createTetrahedron, meshVolume

 ------
 Author: David Legland
 e-mail: david.legland@grignon.inra.fr
 Created: 2012-04-05,    using Matlab 7.9.0.529 (R2009b)
 Copyright 2012 INRA - Cepia Software Platform.

Package: matgeom