code: def lonlat2xyz(lon, lat):
      
  
      lons = np.array(lon)
      lats = np.array(lat)
  
      xs = np.cos(lats) * np.cos(lons)
      ys = np.cos(lats) * np.sin(lons)
      zs = np.sin(lats)
  
      return xs, ys, zs
docs: Convert lon / lat (radians) for the spherical triangulation into x,y,z
      on the unit sphere