[a807206] | 1 | //#define INVALID(v) (v.radius_equat_minor > v.radius_equat_major || v.radius_equat_major > v.radius_polar) |
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[2f5c6d4] | 2 | |
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[2a0b2b1] | 3 | static double |
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| 4 | form_volume(double radius_equat_minor, double radius_equat_major, double radius_polar) |
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[5d4777d] | 5 | { |
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[3a48772] | 6 | return M_4PI_3*radius_equat_minor*radius_equat_major*radius_polar; |
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[5d4777d] | 7 | } |
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| 8 | |
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[71b751d] | 9 | |
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| 10 | static void |
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| 11 | Fq(double q, |
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| 12 | double *F1, |
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| 13 | double *F2, |
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[994d77f] | 14 | double sld, |
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[a807206] | 15 | double sld_solvent, |
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| 16 | double radius_equat_minor, |
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| 17 | double radius_equat_major, |
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| 18 | double radius_polar) |
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[5d4777d] | 19 | { |
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[68dd6a9] | 20 | const double pa = square(radius_equat_minor/radius_equat_major) - 1.0; |
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| 21 | const double pc = square(radius_polar/radius_equat_major) - 1.0; |
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| 22 | // translate a point in [-1,1] to a point in [0, pi/2] |
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| 23 | const double zm = M_PI_4; |
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| 24 | const double zb = M_PI_4; |
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[71b751d] | 25 | double outer_sum_F1 = 0.0; |
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| 26 | double outer_sum_F2 = 0.0; |
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[74768cb] | 27 | for (int i=0;i<GAUSS_N;i++) { |
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| 28 | //const double u = GAUSS_Z[i]*(upper-lower)/2 + (upper + lower)/2; |
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| 29 | const double phi = GAUSS_Z[i]*zm + zb; |
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[68dd6a9] | 30 | const double pa_sinsq_phi = pa*square(sin(phi)); |
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[5d4777d] | 31 | |
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[71b751d] | 32 | double inner_sum_F1 = 0.0; |
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| 33 | double inner_sum_F2 = 0.0; |
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[68dd6a9] | 34 | const double um = 0.5; |
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| 35 | const double ub = 0.5; |
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[74768cb] | 36 | for (int j=0;j<GAUSS_N;j++) { |
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[68dd6a9] | 37 | // translate a point in [-1,1] to a point in [0, 1] |
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[74768cb] | 38 | const double usq = square(GAUSS_Z[j]*um + ub); |
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[68dd6a9] | 39 | const double r = radius_equat_major*sqrt(pa_sinsq_phi*(1.0-usq) + 1.0 + pc*usq); |
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| 40 | const double fq = sas_3j1x_x(q*r); |
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[71b751d] | 41 | inner_sum_F1 += GAUSS_W[j] * fq; |
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| 42 | inner_sum_F2 += GAUSS_W[j] * fq * fq; |
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[5d4777d] | 43 | } |
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[71b751d] | 44 | outer_sum_F1 += GAUSS_W[i] * inner_sum_F1; // correcting for dx later |
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| 45 | outer_sum_F2 += GAUSS_W[i] * inner_sum_F2; // correcting for dx later |
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[5d4777d] | 46 | } |
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[68dd6a9] | 47 | // translate integration ranges from [-1,1] to [lower,upper] and normalize by 4 pi |
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[71b751d] | 48 | outer_sum_F1 *= 0.25; // = outer*um*zm*8.0/(4.0*M_PI); |
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| 49 | outer_sum_F2 *= 0.25; // = outer*um*zm*8.0/(4.0*M_PI); |
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| 50 | |
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| 51 | const double volume = form_volume(radius_equat_minor, radius_equat_major, radius_polar); |
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| 52 | const double contrast = (sld - sld_solvent); |
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| 53 | *F1 = 1.0e-2 * contrast * volume * outer_sum_F1; |
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| 54 | *F2 = 1.0e-4 * square(contrast * volume) * outer_sum_F2; |
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[5d4777d] | 55 | } |
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| 56 | |
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[71b751d] | 57 | |
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[2a0b2b1] | 58 | static double |
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[108e70e] | 59 | Iqabc(double qa, double qb, double qc, |
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[994d77f] | 60 | double sld, |
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[a807206] | 61 | double sld_solvent, |
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| 62 | double radius_equat_minor, |
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| 63 | double radius_equat_major, |
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[becded3] | 64 | double radius_polar) |
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[5d4777d] | 65 | { |
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[2a0b2b1] | 66 | const double qr = sqrt(square(radius_equat_minor*qa) |
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| 67 | + square(radius_equat_major*qb) |
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| 68 | + square(radius_polar*qc)); |
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| 69 | const double fq = sas_3j1x_x(qr); |
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| 70 | const double vol = form_volume(radius_equat_minor, radius_equat_major, radius_polar); |
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| 71 | const double drho = (sld - sld_solvent); |
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[5d4777d] | 72 | |
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[2a0b2b1] | 73 | return 1.0e-4 * square(vol * drho * fq); |
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[5d4777d] | 74 | } |
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