code: def lowes(data):
      
      lmax = data[-1][0]
      Ls = list(range(1, lmax+1))
      Rs = []
      recno = 0
      for l in Ls:
          pow = 0
          for m in range(0, l + 1):
              pow += (l + 1) * ((1e-3 * data[recno][2])
                                ** 2 + (1e-3 * data[recno][3])**2)
              recno += 1
          Rs.append(pow)
      return Ls, Rs
docs: gets Lowe's power spectrum  from gauss coefficients
  
      Parameters
      _________
      data : nested list of [[l,m,g,h],...] as from pmag.unpack()
  
      Returns
      _______
      Ls : list of degrees (l)
      Rs : power at  degree l