Opened 17 months ago

Closed 2 months ago

#896 closed defect (fixed)

equations in core shell parallelepiped docs do not match code

Reported by: pkienzle Owned by: butler
Priority: critical Milestone: SasView 4.2.0
Component: SasView Keywords:
Cc: Work Package: SasModels Redesign


Equations in the core shell parallelepiped docs are incomplete, and what is there does not match the equations in the code.

Change History (9)

comment:1 Changed 17 months ago by richardh

Have made some mods to docs but note still that the equations only have tA not tB, and need verify whether the tC faces are ever present, and if not then either remove them from the parameter list of add say "ignored" or "not used" to their descriptors.

comment:2 Changed 16 months ago by richardh

  • Owner set to butler
  • Status changed from new to assigned

core_shell_parallelepiped is a mess, Miguel made numerous comments in the c code about variants of the calculation hiding in the old libraries, including a comment from someone in 2010 that the IGOR code seemed wrong.

As no-one currently owns this ticket, I am going to assign it to Paul B, to see if he can recall what is going on, as along with Miguel I suspect that the current code is rather wrong.

Meanwhile does anyone have a copies of either of the references please:
P Mittelbach and G Porod, *Acta Physica Austriaca*, 14 (1961) 185-211
R Nayuk and K Huber, *Z. Phys. Chem.*, 226 (2012) 837-854
which is online here

If anyone would like, I do have a copy of this paper by Gille, which has some other references, and a very long analytic correlation function, which can be integratd to give I(Q). It also has an asymptotic expansion of I(Q), which it points out is still highly oscillatory on a Porod plot of Q4.I(Q), but may be useful to compare or include in our calculations.
Journal Appl. Cryst. (1999). 32, 1100-1104
The small-angle scattering correlation function of the cuboid
Wilfried Gille

comment:3 Changed 16 months ago by butler

Sorry - yes this should be mine. Not sure it should actually be a separate ticket but will leave it alone for now as I have no time to deal with it for another week or so. However it really cannot be addressed until #786 is addresses. #786 is the ticket that addresses the correctness of the code (the mess described by @richardh). This ticket technically only speaks to the documentation side (hence why it cannot be addressed till the actual code is worked out).

comment:4 Changed 16 months ago by richardh

My apologies, not meaning to nag, had missed the related #786 for the code itself.

comment:5 Changed 6 months ago by butler

  • Priority changed from minor to critical

comment:6 Changed 5 months ago by butler

In dbf1a60059f2daf9ef240db7a7fbf91cf5de9b9e/sasmodels:

Add comments to c code and clean documentatin

Added comments to c code in both parallelepiped and core shell
parallelepiped noting the change of integration varialbes in the
computation. Cleaned up and final corrections to the core shell
documentation and did some cleaning of parallelipiped. In particular
tried to bring a bit more consistency between the docs.

addresses #896

comment:7 Changed 5 months ago by butler

This is now sasmodels pull request 64 and awaits verification before merging to master. Once done this ticket can be closed.

comment:8 Changed 3 months ago by butler

In fc7bcd59db1fc447402feceb04fd32d3687db1fd/sasmodels:

Final? edits to Parallelepiped (and core shell version) documentation

addresses #896

comment:9 Changed 2 months ago by GitHub <noreply@…>

  • Resolution set to fixed
  • Status changed from assigned to closed

In 052d4c562ddcf34f99db338fed70d5c558214fdb/sasmodels:

Merge pull request #64 from SasView?/ticket-896

Ticket 896 - core shell parallelepiped documentation

closes #896

Note: See TracTickets for help on using tickets.