Orientational Distribution for Magnetic Models

[dirk]

Magnetic models need the angular orientational distribution of magnetic moments around the magnetic field axis.

[pkienzle]

Describe in more detail.

Do you want all orientations within pd degrees of the magentic orientation? Do you have a hard axis and soft axis in a direction independent with more pd in the soft direction than the hard? Do you want this independently for each sld component? Presumably not for the applied field, unless you have problems with field uniformity? Or is it something more complicated?

In any case, this will require some effort since some of the magnetic properties are precomputed outside of the kernel in sasmodels.details.convert_magnetism. This code could be moved into the kernels (increasing code size and runtime cost), or one could move the magnetic orientation polydispersity calculation outside of the kernel, and adjust sasmodels.details, sasmodels.sasview_model.SasviewModel.calculate_Iq and sasmodels.direct_model.call_kernel to suit.

[pkienzle]

Tying magnetism to particle orientation as suggested in #910 may be sufficient. It has the advantage of fewer parameters and all magnetic orientations are correlated. It has the disadvantage that all magnetic orientations are correlated