1 | double _hollow_cylinder_kernel(double q, double core_radius, double radius, |
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2 | double length, double dum); |
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3 | |
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4 | double form_volume(double radius, double core_radius, double length); |
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5 | double Iq(double q, double radius, double core_radius, double length, double sld, |
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6 | double solvent_sld); |
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7 | double Iqxy(double qx, double qy, double radius, double core_radius, double length, double sld, |
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8 | double solvent_sld, double theta, double phi); |
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9 | |
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10 | // From Igor library |
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11 | double _hollow_cylinder_kernel(double q, double core_radius, double radius, |
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12 | double length, double dum) |
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13 | { |
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14 | double gamma,arg1,arg2,lam1,lam2,psi,sinarg,t2,retval; //local variables |
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15 | |
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16 | gamma = core_radius/radius; |
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17 | arg1 = q*radius*sqrt(1.0-dum*dum); //1=shell (outer radius) |
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18 | arg2 = q*core_radius*sqrt(1.0-dum*dum); //2=core (inner radius) |
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19 | if (arg1 == 0.0){ |
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20 | lam1 = 1.0; |
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21 | }else{ |
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22 | lam1 = 2.0*J1(arg1)/arg1; |
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23 | } |
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24 | if (arg2 == 0.0){ |
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25 | lam2 = 1.0; |
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26 | }else{ |
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27 | lam2 = 2.0*J1(arg2)/arg2; |
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28 | } |
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29 | //Todo: Need to check psi behavior as gamma goes to 1. |
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30 | psi = (lam1 - gamma*gamma*lam2)/(1.0-gamma*gamma); //SRK 10/19/00 |
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31 | sinarg = q*length*dum/2.0; |
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32 | if (sinarg == 0.0){ |
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33 | t2 = 1.0; |
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34 | }else{ |
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35 | t2 = sin(sinarg)/sinarg; |
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36 | } |
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37 | |
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38 | retval = psi*psi*t2*t2; |
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39 | |
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40 | return(retval); |
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41 | } |
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42 | |
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43 | double form_volume(double radius, double core_radius, double length) |
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44 | { |
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45 | double pi = 4.0*atan(1.0); |
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46 | double v_shell = pi*length*(radius*radius-core_radius*core_radius); |
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47 | return(v_shell); |
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48 | } |
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49 | |
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50 | double Iq(double q, double radius, double core_radius, double length, double sld, |
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51 | double solvent_sld) |
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52 | { |
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53 | int i; |
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54 | int nord=76; //order of integration |
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55 | double lower,upper,zi, inter; //upper and lower integration limits |
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56 | double summ,answer,delrho; //running tally of integration |
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57 | double norm,scale,volume,convert; //final calculation variables |
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58 | |
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59 | delrho = solvent_sld - sld; |
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60 | lower = 0.0; |
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61 | upper = 1.0; //limits of numerical integral |
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62 | |
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63 | summ = 0.0; //initialize intergral |
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64 | for(i=0;i<nord;i++) { |
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65 | zi = ( Gauss76Z[i] * (upper-lower) + lower + upper )/2.0; |
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66 | inter = Gauss76Wt[i] * _hollow_cylinder_kernel(q, core_radius, radius, length, zi); |
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67 | summ += inter; |
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68 | } |
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69 | |
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70 | norm = summ*(upper-lower)/2.0; |
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71 | // Multiply by contrast^2 |
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72 | scale = delrho*delrho; |
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73 | //normalize by volume |
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74 | volume = form_volume(radius, core_radius, length); |
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75 | //convert to [cm-1] given sld*1e6 |
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76 | convert = 1.0e-4; |
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77 | answer = norm*scale*convert*volume*volume; |
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78 | |
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79 | return(answer); |
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80 | } |
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81 | |
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82 | //TODO: Add this in |
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83 | double Iqxy(double qx, double qy, double radius, double core_radius, double length, double sld, |
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84 | double solvent_sld, double theta, double phi) |
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85 | { |
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86 | return(0.0); |
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87 | } |
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