Changeset 6431056 in sasmodels
- Timestamp:
- Jan 30, 2017 12:00:42 PM (8 years ago)
- Branches:
- master, core_shell_microgels, costrafo411, magnetic_model, ticket-1257-vesicle-product, ticket_1156, ticket_1265_superball, ticket_822_more_unit_tests
- Children:
- cdcebf1
- Parents:
- 3b9a526
- Location:
- sasmodels/models
- Files:
-
- 2 edited
Legend:
- Unmodified
- Added
- Removed
-
sasmodels/models/guinier_porod.py
ra807206 r6431056 4 4 and dimensionality of scattering objects, including asymmetric objects 5 5 such as rods or platelets, and shapes intermediate between spheres 6 and rods or between rods and platelets. 6 and rods or between rods and platelets, and overcomes some of the 7 deficiencies of the (Beaucage) Unified_Power_Rg model (see Hammouda, 2010). 7 8 8 9 Definition … … 59 60 --------- 60 61 61 A Guinier, G Fournet, *Small-Angle Scattering of X-Rays*, 62 John Wiley and Sons, New York, (1955) 62 B Hammouda, *A new GuinierPorod model*, 63 *J. Appl. Cryst.*, (2010), 43, 716-719 63 64 64 O Glatter, O Kratky, *Small-Angle X-Ray Scattering*, Academic Press (1982) 65 Check out Chapter 4 on Data Treatment, pages 155-156. 65 B Hammouda, *Analysis of the Beaucage model*, 66 *J. Appl. Cryst.*, (2010), 43, 14741478 67 66 68 """ 67 69 -
sasmodels/models/unified_power_Rg.py
rb3f2a24 r6431056 3 3 ---------- 4 4 5 Th e Beaucage model employs the empirical multiple level unified6 Exponential/Power-law fit method developed by G. Beaucage. Four functions 7 are included so that 1, 2, 3, or 4 levels can be used. In addition a 0 level 8 has been added which simplycalculates5 This model employs the empirical multiple level unified Exponential/Power-law 6 fit method developed by Beaucage. Four functions are included so that 1, 2, 3, 7 or 4 levels can be used. In addition a 0 level has been added which simply 8 calculates 9 9 10 10 .. math:: … … 15 15 many different types of particles, including fractal clusters, random coils 16 16 (Debye equation), ellipsoidal particles, etc. 17 18 The model works best for *mass* fractal systems characterized by Porod exponents 19 between 5/3 and 3. It should not be used for *surface* fractal systems. Hammouda 20 (2010) has pointed out a deficiency in the way this model handles the 21 transitioning between the Guinier and Porod regimes and which can create 22 artefacts that appear as kinks in the fitted model function. 23 24 Also see the Guinier_Porod model. 17 25 18 26 The empirical fit function is: … … 56 64 57 65 G Beaucage, *J. Appl. Cryst.*, 29 (1996) 134-146 66 67 B Hammouda, *Analysis of the Beaucage model*, 68 *J. Appl. Cryst.*, (2010), 43, 14741478 58 69 59 70 """
Note: See TracChangeset
for help on using the changeset viewer.