Changeset 8de1477 in sasmodels for sasmodels/models/hollow_rectangular_prism.c

Timestamp:

Nov 5, 2017 12:37:54 PM (6 years ago)

Author:

Paul Kienzle <pkienzle@…>

Branches:

master, core_shell_microgels, magnetic_model, ticket-1257-vesicle-product, ticket_1156, ticket_1265_superball, ticket_822_more_unit_tests

Children:

393facf

Parents:

fc0b7aa

Message:

rectangular_prism/hollow_rectangular_prism: add 2d models

File:

• sasmodels/models/hollow_rectangular_prism.c (modified) (3 diffs)

sasmodels/models/hollow_rectangular_prism.c

@@ -1 +1 @@
 double form_volume(double length_a, double b2a_ratio, double c2a_ratio, double thickness);
-double Iq(double q, double sld, double solvent_sld, double length_a, 
+double Iq(double q, double sld, double solvent_sld, double length_a,
           double b2a_ratio, double c2a_ratio, double thickness);
 
@@ -37 +37 @@
     const double v2a = 0.0;
     const double v2b = M_PI_2;  //phi integration limits
-    
+
     double outer_sum = 0.0;
     for(int i=0; i<76; i++) {
@@ -84 +84 @@
     return 1.0e-4 * delrho * delrho * form;
 }
+
+double Iqxy(double qa, double qb, double qc,
+    double sld,
+    double solvent_sld,
+    double length_a,
+    double b2a_ratio,
+    double c2a_ratio,
+    double thickness)
+{
+    const double length_b = length_a * b2a_ratio;
+    const double length_c = length_a * c2a_ratio;
+    const double a_half = 0.5 * length_a;
+    const double b_half = 0.5 * length_b;
+    const double c_half = 0.5 * length_c;
+    const double vol_total = length_a * length_b * length_c;
+    const double vol_core = 8.0 * (a_half-thickness) * (b_half-thickness) * (c_half-thickness);
+
+    // Amplitude AP from eqn. (13)
+
+    const double termA1 = sas_sinx_x(qa * a_half);
+    const double termA2 = sas_sinx_x(qa * (a_half-thickness));
+
+    const double termB1 = sas_sinx_x(qb * b_half);
+    const double termB2 = sas_sinx_x(qb * (b_half-thickness));
+
+    const double termC1 = sas_sinx_x(qc * c_half);
+    const double termC2 = sas_sinx_x(qc * (c_half-thickness));
+
+    const double AP1 = vol_total * termA1 * termB1 * termC1;
+    const double AP2 = vol_core * termA2 * termB2 * termC2;
+
+    // Multiply by contrast^2. Factor corresponding to volume^2 cancels with previous normalization.
+    const double delrho = sld - solvent_sld;
+
+    // Convert from [1e-12 A-1] to [cm-1]
+    return 1.0e-4 * square(delrho * (AP1-AP2));
+}