def conv(n, p):
   S0, S1, S2, S3 = polarization_normal_to_stokes(n, p)
   return polarization_stokes_to_normal(S0, S1, S2, S3)
 def conv(n, p):
     S0, S1, S2, S3 = polarization_normal_to_stokes(n, p)
     return polarization_stokes_to_normal(S0, S1, S2, S3)