I have found this code written in python showing a visualization of the Roadster's orbit around Earth using Skyfield library. I had trouble understanding following piece of code snippets in terms of its physical importance to the visualization.
theta = np.linspace(0, twopi, 201) cth, sth, zth = [f(theta) for f in (np.cos, np.sin, np.zeros_like)] lon0 = re*np.vstack((cth, zth, sth)) lons =  for phi in rads*np.arange(0, 180, 15): cph, sph = [f(phi) for f in (np.cos, np.sin)] lon = np.vstack((lon0*cph - lon0*sph, lon0*cph + lon0*sph, lon0) ) lons.append(lon) lat0 = re*np.vstack((cth, sth, zth)) lats =  for phi in rads*np.arange(-75, 90, 15): cph, sph = [f(phi) for f in (np.cos, np.sin)] lat = re*np.vstack((cth*cph, sth*cph, zth+sph)) lats.append(lat)
Briefly, I am having trouble understanding some "magic" numbers that appear around the code. I would really appreciate if someone can walk me through at least this piece of code if not the full.