Opened 2 years ago

Last modified 7 months ago

#894 new defect

triaxial ellipsoid with circular equator does not match ellipsoid

Reported by: pkienzle Owned by:
Priority: major Milestone: SasView 4.3.0
Component: SasView Keywords:
Cc: Work Package: SasModels Model Issues

Description

Comparing ellipsoid with triaxial ellipsoid where the equatorial major and minor axes of the triaxial ellipsoid match the equatorial radius of the ellipsoid yields different results. This is true in SasView 3.1.x as well, for both 1D and 2D models.

Change History (5)

comment:1 Changed 2 years ago by pkienzle

Note: formula for form factor does not match calculation in the triaxial ellipsoid (1D).

Formula inside integral in help says:

    Phi^2[ q R_a^2 cos^2(pi/2 x) + q R_b^2 sin^2(pi/2 y)(1-y^2) + R_c^2 y^2 ]

Code says:

    Phi^2[ q sqrt(R_a^2 cos^2(pi/2 x) + R_b^2 sin^2(pi/2 y)(1-y^2) + R_c^2 y^2) ]

comment:2 Changed 2 years ago by pkienzle

The following gives an alternative formula for the 1-D triaxial ellipsoid:

http://iopscience.iop.org/0022-3727/4/1/310

This gives a result consistent with ellipsoid.

Last edited 2 years ago by pkienzle (previous) (diff)

comment:3 Changed 2 years ago by butler

  • Work Package changed from SasModels Redesign to SasModels New Model

comment:4 Changed 19 months ago by butler

  • Milestone changed from SasView 4.2.0 to SasView 4.3.0

comment:5 Changed 7 months ago by butler

  • Work Package changed from SasModels New Model to SasModels Model Issues
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