HDD This code is Hawaii Disambiguity Decoder (HDD) under the SPIN4D project. It is used to disambiguate the azimuthal angle of the magnetic field from the Stokes polarimetric data inversion. It can disambiguate the horizontal magnetic field with a 180-degree ambiguity and give the prediction of the vertical height based on the divergence equation. It is a very weak constraint on the data, but it works well. v0.0.1 2023/11/17 K. Y. yangkai@hawaii.edu Currently under test