| 1 | static double |
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| 2 | form_volume(double radius, double thick_rim, double thick_face, double length) |
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| 3 | { |
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| 4 | return M_PI*square(radius+thick_rim)*(length+2.0*thick_face); |
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| 5 | } |
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| 6 | |
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| 7 | static double |
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| 8 | bicelle_kernel(double qab, |
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| 9 | double qc, |
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| 10 | double radius, |
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| 11 | double thick_radius, |
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| 12 | double thick_face, |
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| 13 | double halflength, |
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| 14 | double sld_core, |
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| 15 | double sld_face, |
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| 16 | double sld_rim, |
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| 17 | double sld_solvent) |
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| 18 | { |
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| 19 | const double dr1 = sld_core-sld_face; |
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| 20 | const double dr2 = sld_rim-sld_solvent; |
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| 21 | const double dr3 = sld_face-sld_rim; |
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| 22 | const double vol1 = M_PI*square(radius)*2.0*(halflength); |
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| 23 | const double vol2 = M_PI*square(radius+thick_radius)*2.0*(halflength+thick_face); |
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| 24 | const double vol3 = M_PI*square(radius)*2.0*(halflength+thick_face); |
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| 25 | |
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| 26 | const double be1 = sas_2J1x_x((radius)*qab); |
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| 27 | const double be2 = sas_2J1x_x((radius+thick_radius)*qab); |
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| 28 | const double si1 = sas_sinx_x((halflength)*qc); |
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| 29 | const double si2 = sas_sinx_x((halflength+thick_face)*qc); |
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| 30 | |
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| 31 | const double t = vol1*dr1*si1*be1 + |
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| 32 | vol2*dr2*si2*be2 + |
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| 33 | vol3*dr3*si2*be1; |
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| 34 | |
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| 35 | return t; |
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| 36 | } |
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| 37 | |
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| 38 | static double |
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| 39 | Iq(double q, |
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| 40 | double radius, |
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| 41 | double thick_radius, |
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| 42 | double thick_face, |
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| 43 | double length, |
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| 44 | double sld_core, |
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| 45 | double sld_face, |
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| 46 | double sld_rim, |
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| 47 | double sld_solvent) |
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| 48 | { |
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| 49 | // set up the integration end points |
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| 50 | const double uplim = M_PI_4; |
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| 51 | const double halflength = 0.5*length; |
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| 52 | |
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| 53 | double total = 0.0; |
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| 54 | for(int i=0;i<GAUSS_N;i++) { |
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| 55 | double theta = (GAUSS_Z[i] + 1.0)*uplim; |
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| 56 | double sin_theta, cos_theta; // slots to hold sincos function output |
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| 57 | SINCOS(theta, sin_theta, cos_theta); |
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| 58 | double fq = bicelle_kernel(q*sin_theta, q*cos_theta, radius, thick_radius, thick_face, |
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| 59 | halflength, sld_core, sld_face, sld_rim, sld_solvent); |
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| 60 | total += GAUSS_W[i]*fq*fq*sin_theta; |
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| 61 | } |
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| 62 | |
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| 63 | // calculate value of integral to return |
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| 64 | double answer = total*uplim; |
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| 65 | return 1.0e-4*answer; |
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| 66 | } |
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| 67 | |
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| 68 | static double |
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| 69 | Iqac(double qab, double qc, |
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| 70 | double radius, |
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| 71 | double thick_rim, |
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| 72 | double thick_face, |
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| 73 | double length, |
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| 74 | double core_sld, |
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| 75 | double face_sld, |
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| 76 | double rim_sld, |
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| 77 | double solvent_sld) |
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| 78 | { |
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| 79 | double fq = bicelle_kernel(qab, qc, radius, thick_rim, thick_face, |
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| 80 | 0.5*length, core_sld, face_sld, rim_sld, |
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| 81 | solvent_sld); |
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| 82 | return 1.0e-4*fq*fq; |
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| 83 | } |
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