Opened 8 years ago
Last modified 5 years ago
#492 closed enhancement
choice of parameterization of orientation angles — at Version 3
| Reported by: | butler | Owned by: | butler |
|---|---|---|---|
| Priority: | major | Milestone: | SasView 4.2.0 |
| Component: | SasView | Keywords: | |
| Cc: | Work Package: | SasModels Infrastructure |
Description (last modified by butler)
The current orientation angles, while they seem to be correct, are not natural for the user.
For the cylinder, it would be preferable if theta were the angle of the cylinder axis with respect to the beam, with 0 corresponding to a cylinder along the beam, and a circular scattering pattern, and 90 corresponding to a cylinder perpendicular to the beam. This corresponds to latitude. The angle phi ranging from -180 to 180 would rotate the cylinder in a circle of constant angle theta, corresponding to longitude.
This would allow users to set phi by inspection since it would be mostly independent of theta. It would also allow for faster phi polydispersity since a fixed 2D image could be used without having to recompute it for each phi, much like we will (eventually) be doing for 2D resolution
This would require redoing the model maths and needs broader agreement than just "fixing"
Change History (3)
comment:1 Changed 8 years ago by pkienzle
comment:2 Changed 8 years ago by butler
- Owner set to richardh
- Status changed from new to assigned
comment:3 Changed 8 years ago by butler
- Description modified (diff)
- Owner changed from richardh to butler
- Priority changed from blocker to critical
- Summary changed from check orientation angles to choice of parameterization of orientation angles
- Type changed from defect to enhancement
- Work Package changed from SasView QA and testing to SasModels Redesign
The current orientation angles, while the seem to be correct, are not natural for the user.
For the cylinder, it would be preferable if theta were the angle of the cylinder axis with respect to the beam, with 0 corresponding to a cylinder along the beam, and a circular scattering pattern, and 90 corresponding to a cylinder perpendicular to the beam. This corresponds to latitude. The angle phi ranging from -180 to 180 would rotate the cylinder in a circle of constant angle theta, corresponding to longitude.
This would allow users to set phi by inspection since it would be mostly independent of theta. It would also allow for faster phi polydispersity since a fixed 2D image could be used without having to recompute it for each phi, much like we will (eventually) be doing for 2D resolution.