Convert 3D Cartesian to spherical coordinates
car2sph(x)3-element or n-by-3 matrix representing the Cartesian components (x,y,z) of n three-dimensional vectors
Returns a 3-element vector or a n-by-3 element matrix representing the spherical coordinates (r,theta,phi), where theta=0...pi is the polar angle measured from the north pole and phi=0...2*pi is the azimuth measured positively from the x-axis (ISO 80000-2:2019 physics convention).