Changeset 7e0b281 in sasmodels for sasmodels/models/sc_paracrystal.c
- Timestamp:
- Apr 17, 2017 6:34:52 PM (7 years ago)
- Branches:
- master, core_shell_microgels, magnetic_model, ticket-1257-vesicle-product, ticket_1156, ticket_1265_superball, ticket_822_more_unit_tests
- Children:
- 64ca163
- Parents:
- cb038a2
- File:
-
- 1 edited
Legend:
- Unmodified
- Added
- Removed
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sasmodels/models/sc_paracrystal.c
r2a0b2b1 r7e0b281 1 1 static double 2 _sq_sc(double qa, double qb, double qc, double dnn, double d_factor)2 sc_Zq(double qa, double qb, double qc, double dnn, double d_factor) 3 3 { 4 // Rewriting equations for efficiency, accuracy and readability, and so5 // code is reusable between 1D and 2D models.6 4 const double a1 = qa; 7 5 const double a2 = qb; 8 6 const double a3 = qc; 9 7 10 const double arg = 0.5*square(dnn*d_factor)*(a1*a1 + a2*a2 + a3*a3);11 12 8 // Numerator: (1 - exp(a)^2)^3 13 9 // => (-(exp(2a) - 1))^3 14 10 // => -expm1(2a)^3 15 // Denominator: prod(1 - 2 cos(xk) exp(a) + exp(a)^2) 16 // => exp(a)^2 - 2 cos(xk) exp(a) + 1 17 // => (exp(a) - 2 cos(xk)) * exp(a) + 1 18 const double exp_arg = exp(-arg); 19 const double Sq = -cube(expm1(-2.0*arg)) 11 // Denominator: prod(1 - 2 cos(d ak) exp(a) + exp(2a)) 12 // => prod(exp(a)^2 - 2 cos(d ak) exp(a) + 1) 13 // => prod((exp(a) - 2 cos(d ak)) * exp(a) + 1) 14 const double arg = -0.5*square(dnn*d_factor)*(a1*a1 + a2*a2 + a3*a3); 15 const double exp_arg = exp(arg); 16 const double Zq = -cube(expm1(2.0*arg)) 20 17 / ( ((exp_arg - 2.0*cos(dnn*a1))*exp_arg + 1.0) 21 18 * ((exp_arg - 2.0*cos(dnn*a2))*exp_arg + 1.0) 22 19 * ((exp_arg - 2.0*cos(dnn*a3))*exp_arg + 1.0)); 23 20 24 return Sq;21 return Zq; 25 22 } 26 23 27 24 // occupied volume fraction calculated from lattice symmetry and sphere radius 28 25 static double 29 _sc_volume_fraction(double radius, double dnn)26 sc_volume_fraction(double radius, double dnn) 30 27 { 31 28 return sphere_volume(radius/dnn); … … 65 62 const double qa = qab*cos_phi; 66 63 const double qb = qab*sin_phi; 67 const double f q = _sq_sc(qa, qb, qc, dnn, d_factor);68 inner_sum += Gauss150Wt[j] * f q;64 const double form = sc_Zq(qa, qb, qc, dnn, d_factor); 65 inner_sum += Gauss150Wt[j] * form; 69 66 } 70 67 inner_sum *= phi_m; // sum(f(x)dx) = sum(f(x)) dx … … 72 69 } 73 70 outer_sum *= theta_m; 74 const double Sq = outer_sum/M_PI_2;71 const double Zq = outer_sum/M_PI_2; 75 72 const double Pq = sphere_form(q, radius, sld, solvent_sld); 76 73 77 return _sc_volume_fraction(radius, dnn) * Pq * Sq;74 return sc_volume_fraction(radius, dnn) * Pq * Zq; 78 75 } 79 76 … … 92 89 q = sqrt(qa*qa + qb*qb + qc*qc); 93 90 const double Pq = sphere_form(q, radius, sld, solvent_sld); 94 const double Sq = _sq_sc(qa, qb, qc, dnn, d_factor);95 return _sc_volume_fraction(radius, dnn) * Pq * Sq;91 const double Zq = sc_Zq(qa, qb, qc, dnn, d_factor); 92 return sc_volume_fraction(radius, dnn) * Pq * Zq; 96 93 }
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