name&dimensionality 
kind 
in/out 
description 




vector(3) 
DP 
IN 
three dimensional cartesian position vector
(x,y,z). The north pole is (0,0,1) 
theta 
DP 
OUT 
colatitude in radians measured southward from north pole (in
[0,]). 
phi 
DP 
OUT 
longitude in radians measured eastward (in [0, ]). 