Prefactor calculation when there are both P(Q) and S(Q) (Trac #1259)

[sasview-bot]

The models for vesicle and sphere systems ( P(Q) ) with the hard sphere interaction ( S(Q) ) have two volume fraction: phi_PQ and phi_SQ.
phi_PQ is the volume fraction from the form factor.
phi_SQ is the volume fraction from the structure factor.

Based on the testing of the two models, the prefactor of the scattering intensity is currently set up to be proportional to scale*phi_PQ*phi_SQ.

If the scale is set up to one, the prefactor with the absolute intensity should be proportional to phi_PQ only.
It should not be phi_PQ*phi_SQ.

It is suggested to remove phi_SQ from the calculation of the prefactor.

[sasview-bot]

Trac update at 2019/03/26 10:16:46: yunliu changed attachment from "" to "TestResults-SphereVesicles-SASView.docx"

[sasview-bot]

Trac update at 2019/03/26 10:21:09: yunliu changed milestone from "SasView 5.1.0" to "SasView 5.0.0"

[sasview-bot]

Trac update at 2019/03/26 10:22:38: yunliu commented:

Forgot to mention that the prefactor calculation is the same for both V4.1.2 and V5.0.

[pkienzle]

Trac update at 2019/03/29 20:11:17: pkienzle commented:

I think this is duplicate of SasView/sasview#1280, and is fixed by the following sasmodels PR

https://github.com/SasView/sasmodels/pull/101

Changes between 4 and 5 probably depend on which version of sasmodels is active.

[pkienzle]

This is a GUI problem in SasView 5.0: move to sasview issues