plot a section through a spherical function
N = vector3d.Z; % normal direction plotSection(sF,N) % plot in equator plane
theta = pi/3; % polar angle plotSection(sF,N,theta) % plot small circle at 30 degree from the north pole
rho = linspace(0,pi); % azimuth angle plotSection(sF,N,theta,rho) % plot half small circle at 30 degree