code: def raDecFromVec(v):
      
  
      #Ensure v is a normal vector
      v /= np.linalg.norm(v)
  
      ra_deg=0    #otherwise not in namespace0
      dec_rad = np.arcsin(v[2])
      s = np.hypot(v[0], v[1])
      if s ==0:
          ra_rad = 0
      else:
          ra_rad = np.arcsin(v[1]/s)
          ra_deg = np.degrees(ra_rad)
          if v[0] >= 0:
              if v[1] >= 0:
                  pass
              else:
                  ra_deg = 360 + ra_deg
          else:
              if v[1] > 0:
                  ra_deg = 180 - ra_deg
              else:
                  ra_deg = 180 - ra_deg
  
      raDec = ra_deg, np.degrees(dec_rad)
      return np.array(raDec)
docs: Taken from
      http://www.math.montana.edu/frankw/ccp/multiworld/multipleIVP/spherical/learn.htm
      Search for "convert from Cartestion to spherical coordinates"
  
      Adapted because I'm dealing with declination which is defined
      with 90degrees at zenith