capped_cylinder & barbell docs and/or computations could be improved (Trac #542)

[RichardHeenan]

capped_cylinder computations could be improved - see notes included in the .py file, current model requires user to keep cap radius > cylinder radius

ticket submitted by Richard, but assigned to PAK, who may know what to do.

Migrated from http://trac.sasview.org/ticket/542

{
    "status": "new",
    "changetime": "2018-10-06T16:28:31",
    "_ts": "2018-10-06 16:28:31.061990+00:00",
    "description": "capped_cylinder computations could be improved  - see notes included in the .py file, current model requires user to keep cap radius > cylinder radius\n\nticket submitted by Richard, but assigned to PAK, who may know what to do.",
    "reporter": "richardh",
    "cc": "",
    "resolution": "",
    "workpackage": "SasView QA and testing",
    "time": "2016-03-19T22:14:15",
    "component": "sasmodels",
    "summary": "capped_cylinder & barbell docs and/or computations could be improved",
    "priority": "minor",
    "keywords": "",
    "milestone": "SasView 4.3.0",
    "owner": "pkienzle",
    "type": "enhancement"
}

[ajj]

Trac update at 2017/01/17 13:05:47: ajj changed component from "SansView" to "SasView"

[RichardHeenan]

Trac update at 2018/09/12 17:00:27:

• richardh commented:

Whilst looking at ER calcs for barbell and capped_cylinder I note that there seems to be inconsistencies between the docs and the calculations. I suspect the calculation is OK but the docs need improvement?

e.g. concerning the sign of distance h, where for both models the docs say h is negative, but a note in capped_cylinder.c says it is positive.

e.g docs for both say "The scale factor is equivalent to the volume fraction of cylinders, each of volume, V" which is a little odd?

Suspect the orignal goal of this ticket to improve capped_cylinder calculations may have been done ? (need to look at github ...)

• richardh changed component from "SasView" to "sasmodels"
• richardh changed milestone from "SasView Next Release +1" to "sasmodels WishList"
• richardh changed summary from "capped_cylinder computations could be improved" to "capped_cylinder & barbell docs and/or computations could be improved"

[butlerpd]

Trac update at 2018/10/06 16:28:31:

• butler commented:

maybe this can be addressed in 4.3 along with paracrystalline models and validation of the be_polyelectrolyte

• butler changed milestone from "sasmodels WishList" to "SasView 4.3.0"