Changeset 500128b in sasmodels


Ignore:
Timestamp:
Jun 24, 2016 6:01:28 PM (8 years ago)
Author:
Paul Kienzle <pkienzle@…>
Branches:
master, core_shell_microgels, costrafo411, magnetic_model, release_v0.94, release_v0.95, ticket-1257-vesicle-product, ticket_1156, ticket_1265_superball, ticket_822_more_unit_tests
Children:
59d94b3
Parents:
b3a85cd
Message:

latex cleanup

Location:
sasmodels/models
Files:
3 edited

Legend:

Unmodified
Added
Removed
  • sasmodels/models/core_shell_parallelepiped.py

    rec45c4f r500128b  
    66can be different on all three (pairs) of faces.** 
    77 
    8 The form factor is normalized by the particle volume *V* such that 
     8The form factor is normalized by the particle volume $V$ such that 
    99 
    10 *I(q)* = *scale* \* <*f*\ :sup:`2`> / *V* + *background* 
     10.. math:: 
    1111 
    12 where < > is an average over all possible orientations of the rectangular solid. 
     12    I(q) = \text{scale}\frac{\langle f^2 \rangle}{V} + \text{background} 
     13 
     14where $\langle \ldots \rangle$ is an average over all possible orientations 
     15of the rectangular solid. 
    1316 
    1417An instrument resolution smeared version of the model is also provided. 
     
    1922 
    2023The function calculated is the form factor of the rectangular solid below. 
    21 The core of the solid is defined by the dimensions *A*, *B*, *C* such that 
    22 *A* < *B* < *C*. 
     24The core of the solid is defined by the dimensions $A$, $B$, $C$ such that 
     25$A < B < C$. 
    2326 
    2427.. image:: img/core_shell_parallelepiped_geometry.jpg 
    2528 
    26 There are rectangular "slabs" of thickness $t_A$ that add to the *A* dimension 
    27 (on the *BC* faces). There are similar slabs on the *AC* $(=t_B)$ and *AB* 
    28 $(=t_C)$ faces. The projection in the *AB* plane is then 
     29There are rectangular "slabs" of thickness $t_A$ that add to the $A$ dimension 
     30(on the $BC$ faces). There are similar slabs on the $AC$ $(=t_B)$ and $AB$ 
     31$(=t_C)$ faces. The projection in the $AB$ plane is then 
    2932 
    3033.. image:: img/core_shell_parallelepiped_projection.jpg 
     
    4346 
    4447**For the calculation of the form factor to be valid, the sides of the solid 
    45 MUST be chosen such that** *A* < *B* < *C*. 
     48MUST be chosen such that** $A < B < C$. 
    4649**If this inequality is not satisfied, the model will not report an error, 
    4750and the calculation will not be correct.** 
     
    4952FITTING NOTES 
    5053If the scale is set equal to the particle volume fraction, |phi|, the returned 
    51 value is the scattered intensity per unit volume; ie, *I(q)* = |phi| *P(q)*. 
     54value is the scattered intensity per unit volume, $I(q) = \phi P(q)$. 
    5255However, **no interparticle interference effects are included in this calculation.** 
    5356 
     
    5659 
    5760Constraints must be applied during fitting to ensure that the inequality 
    58 *A* < *B* < *C* is not violated. The calculation will not report an error, 
     61$A < B < C$ is not violated. The calculation will not report an error, 
    5962but the results will not be correct. 
    6063 
     
    6467based on the the averaged effective radius $(=\sqrt{(A+2t_A)(B+2t_B)/\pi})$ 
    6568and length $(C+2t_C)$ values, and used as the effective radius 
    66 for *S(Q)* when *P(Q)* \* *S(Q)* is applied. 
     69for $S(Q)$ when $P(Q) * S(Q)$ is applied. 
    6770 
    6871.. Comment by Miguel Gonzalez: 
     
    7174 
    7275To provide easy access to the orientation of the parallelepiped, we define the 
    73 axis of the cylinder using three angles |theta|, |phi| and |bigpsi|. 
     76axis of the cylinder using three angles $\theta$, $\phi$ and $\Psi$. 
    7477(see :ref:`cylinder orientation <cylinder-angle-definition>`). 
    75 The angle |bigpsi| is the rotational angle around the *long_c* axis against the 
    76 *q* plane. For example, |bigpsi| = 0 when the *short_b* axis is parallel to the 
     78The angle $\Psi$ is the rotational angle around the *long_c* axis against the 
     79$q$ plane. For example, $\Psi = 0$ when the *short_b* axis is parallel to the 
    7780*x*-axis of the detector. 
    7881 
  • sasmodels/models/lamellar.py

    rec45c4f r500128b  
    99.. math:: 
    1010 
    11     I(q) = scale*\frac{2\pi P(q)}{q^2\delta } 
     11    I(q) = \text{scale}\frac{2\pi P(q)}{q^2\delta} + \text{background} 
    1212 
    1313 
     
    1616.. math:: 
    1717 
    18    P(q) = \frac{2\Delta\rho^2}{q^2}(1-cos(q\delta)) = \frac{4\Delta\rho^2}{q^2}sin^2(\frac{q\delta}{2}) 
     18   P(q) = \frac{2\Delta\rho^2}{q^2}(1-\cos(q\delta)) 
     19        = \frac{4\Delta\rho^2}{q^2}\sin^2\left(\frac{q\delta}{2}\right) 
    1920 
    2021where $\delta$ is the total layer thickness and $\Delta\rho$ is the scattering length density difference. 
  • sasmodels/models/sc_paracrystal.py

    rec45c4f r500128b  
    1313.. math:: 
    1414 
    15     I(q) = \frac{scale}{V_p}V_{lattice}P(q)Z(q) 
     15    I(q) = \text{scale}\frac{V_\text{lattice}P(q)Z(q)}{V_p} + \text{background} 
    1616 
    1717where scale is the volume fraction of spheres, $V_p$ is the volume of 
    18 the primary particle, $V_{lattice}$ is a volume correction for the crystal 
     18the primary particle, $V_\text{lattice}$ is a volume correction for the crystal 
    1919structure, $P(q)$ is the form factor of the sphere (normalized), and 
    2020$Z(q)$ is the paracrystalline structure factor for a simple cubic structure. 
     
    2828.. math:: 
    2929 
    30     V_{lattice}=\frac{4\pi}{3}\frac{R^3}{D^3} 
     30    V_\text{lattice}=\frac{4\pi}{3}\frac{R^3}{D^3} 
    3131 
    3232The distortion factor (one standard deviation) of the paracrystal is included 
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