Changeset 71b751d in sasmodels for sasmodels/models/hollow_rectangular_prism_thin_walls.c

Timestamp:

Aug 14, 2018 12:09:34 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:

86aa992

Parents:

2f8cbb9

Message:

update remaining form factors to use Fq interface

File:

• sasmodels/models/hollow_rectangular_prism_thin_walls.c (modified) (4 diffs)

sasmodels/models/hollow_rectangular_prism_thin_walls.c

@@ -8 +8 @@
 }
 
-static double
-Iq(double q,
+static void
+Fq(double q,
+    double *F1,
+    double *F2,
     double sld,
     double solvent_sld,
@@ -28 +30 @@
     const double v2b = M_PI_2;  //phi integration limits
 
-    double outer_sum = 0.0;
+    double outer_sum_F1 = 0.0;
+    double outer_sum_F2 = 0.0;
     for(int i=0; i<GAUSS_N; i++) {
         const double theta = 0.5 * ( GAUSS_Z[i]*(v1b-v1a) + v1a + v1b );
@@ -41 +44 @@
         const double termAT_theta = 8.0 * sin_c / (q*q*sin_theta*cos_theta);
 
-        double inner_sum = 0.0;
+        double inner_sum_F1 = 0.0;
+        double inner_sum_F2 = 0.0;
         for(int j=0; j<GAUSS_N; j++) {
             const double phi = 0.5 * ( GAUSS_Z[j]*(v2b-v2a) + v2a + v2b );
@@ -60 +64 @@
                 * ( cos_a*sin_b/cos_phi + cos_b*sin_a/sin_phi );
 
-            inner_sum += GAUSS_W[j] * square(AL+AT);
+            inner_sum_F1 += GAUSS_W[j] * (AL+AT);
+            inner_sum_F2 += GAUSS_W[j] * square(AL+AT);
         }
 
-        inner_sum *= 0.5 * (v2b-v2a);
-        outer_sum += GAUSS_W[i] * inner_sum * sin_theta;
+        inner_sum_F1 *= 0.5 * (v2b-v2a);
+        inner_sum_F2 *= 0.5 * (v2b-v2a);
+        outer_sum_F1 += GAUSS_W[i] * inner_sum_F1 * sin_theta;
+        outer_sum_F2 += GAUSS_W[i] * inner_sum_F2 * sin_theta;
     }
 
-    outer_sum *= 0.5*(v1b-v1a);
+    outer_sum_F1 *= 0.5*(v1b-v1a);
+    outer_sum_F2 *= 0.5*(v1b-v1a);
 
     // Normalize as in Eqn. (15) without the volume factor (as cancels with (V*DelRho)^2 normalization)
     // The factor 2 is due to the different theta integration limit (pi/2 instead of pi)
-    double answer = outer_sum/M_PI_2;
+    const double form_avg = outer_sum_F1/M_PI_2;
+    const double form_squared_avg = outer_sum_F2/M_PI_2;
 
     // Multiply by contrast^2. Factor corresponding to volume^2 cancels with previous normalization.
-    answer *= square(sld-solvent_sld);
+    const double contrast = sld - solvent_sld;
 
     // Convert from [1e-12 A-1] to [cm-1]
-    answer *= 1.0e-4;
-
-    return answer;
+    *F1 = 1e-2 * contrast * form_avg;
+    *F2 = 1e-4 * contrast * contrast * form_squared_avg;
 }