source: sasmodels/sasmodels/models/core_shell_ellipsoid.c @ 2d81cfe

core_shell_microgelsmagnetic_modelticket-1257-vesicle-productticket_1156ticket_1265_superballticket_822_more_unit_tests
Last change on this file since 2d81cfe was becded3, checked in by Paul Kienzle <pkienzle@…>, 6 years ago

update oriented models to new interface (which will be in the next commit)

  • Property mode set to 100644
File size: 3.3 KB
Line 
1
2// Converted from Igor function gfn4, using the same pattern as ellipsoid
3// for evaluating the parts of the integral.
4//     FUNCTION gfn4:    CONTAINS F(Q,A,B,MU)**2  AS GIVEN
5//                       BY (53) & (58-59) IN CHEN AND
6//                       KOTLARCHYK REFERENCE
7//
8//       <OBLATE ELLIPSOID>
9static double
10_cs_ellipsoid_kernel(double qab, double qc,
11    double equat_core, double polar_core,
12    double equat_shell, double polar_shell,
13    double sld_core_shell, double sld_shell_solvent)
14{
15    const double qr_core = sqrt(square(equat_core*qab) + square(polar_core*qc));
16    const double si_core = sas_3j1x_x(qr_core);
17    const double volume_core = M_4PI_3*equat_core*equat_core*polar_core;
18    const double fq_core = si_core*volume_core*sld_core_shell;
19
20    const double qr_shell = sqrt(square(equat_shell*qab) + square(polar_shell*qc));
21    const double si_shell = sas_3j1x_x(qr_shell);
22    const double volume_shell = M_4PI_3*equat_shell*equat_shell*polar_shell;
23    const double fq_shell = si_shell*volume_shell*sld_shell_solvent;
24
25    return fq_core + fq_shell;
26}
27
28static double
29form_volume(double radius_equat_core,
30    double x_core,
31    double thick_shell,
32    double x_polar_shell)
33{
34    const double equat_shell = radius_equat_core + thick_shell;
35    const double polar_shell = radius_equat_core*x_core + thick_shell*x_polar_shell;
36    double vol = M_4PI_3*equat_shell*equat_shell*polar_shell;
37    return vol;
38}
39
40static double
41Iq(double q,
42    double radius_equat_core,
43    double x_core,
44    double thick_shell,
45    double x_polar_shell,
46    double core_sld,
47    double shell_sld,
48    double solvent_sld)
49{
50    const double sld_core_shell = core_sld - shell_sld;
51    const double sld_shell_solvent = shell_sld - solvent_sld;
52
53    const double polar_core = radius_equat_core*x_core;
54    const double equat_shell = radius_equat_core + thick_shell;
55    const double polar_shell = radius_equat_core*x_core + thick_shell*x_polar_shell;
56
57    // translate from [-1, 1] => [0, 1]
58    const double m = 0.5;
59    const double b = 0.5;
60    double total = 0.0;     //initialize intergral
61    for(int i=0;i<76;i++) {
62        const double cos_theta = Gauss76Z[i]*m + b;
63        const double sin_theta = sqrt(1.0 - cos_theta*cos_theta);
64        double fq = _cs_ellipsoid_kernel(q*sin_theta, q*cos_theta,
65            radius_equat_core, polar_core,
66            equat_shell, polar_shell,
67            sld_core_shell, sld_shell_solvent);
68        total += Gauss76Wt[i] * fq * fq;
69    }
70    total *= m;
71
72    // convert to [cm-1]
73    return 1.0e-4 * total;
74}
75
76static double
77Iqxy(double qab, double qc,
78    double radius_equat_core,
79    double x_core,
80    double thick_shell,
81    double x_polar_shell,
82    double core_sld,
83    double shell_sld,
84    double solvent_sld)
85{
86    const double sld_core_shell = core_sld - shell_sld;
87    const double sld_shell_solvent = shell_sld - solvent_sld;
88
89    const double polar_core = radius_equat_core*x_core;
90    const double equat_shell = radius_equat_core + thick_shell;
91    const double polar_shell = radius_equat_core*x_core + thick_shell*x_polar_shell;
92
93    double fq = _cs_ellipsoid_kernel(qab, qc,
94                  radius_equat_core, polar_core,
95                  equat_shell, polar_shell,
96                  sld_core_shell, sld_shell_solvent);
97
98    //convert to [cm-1]
99    return 1.0e-4 * fq * fq;
100}
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