Changeset 3a48772 in sasmodels for sasmodels/models/star_polymer.c

Timestamp:

Oct 14, 2016 5:23:40 PM (8 years ago)

Author:

Paul Kienzle <pkienzle@…>

Branches:

master, core_shell_microgels, costrafo411, magnetic_model, ticket-1257-vesicle-product, ticket_1156, ticket_1265_superball, ticket_822_more_unit_tests

Children:

a5b6997

Parents:

b716cc6

Message:

use predefined constants for fractions of pi

File:

• sasmodels/models/star_polymer.c (modified) (1 diff)

sasmodels/models/star_polymer.c

@@ -6 +6 @@
 {
 
-    double u_2 = radius2 * pow(q,2);
+    double u_2 = radius2 * q * q;
     double v = u_2 * arms / (3.0 * arms - 2.0);
 
-    double term1 = v - 1.0 + exp(-v);
-    double term2 = ((arms - 1.0)/2.0)* pow((1.0 - exp(-v)),2.0);
+    double term1 = v + expm1(-v);
+    double term2 = ((arms - 1.0)/2.0) * square(expm1(-v));
 
-    return (2.0 * (term1 + term2)) / (arms * pow(v,2.0));
+    return (2.0 * (term1 + term2)) / (arms * v * v);
 
 }