1 | """ |
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2 | P(r) inversion for SAS |
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3 | """ |
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4 | ## \mainpage P(r) inversion for SAS |
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5 | # |
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6 | # \section intro_sec Introduction |
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7 | # This module provides calculations to transform scattering intensity data |
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8 | # I(q) into distance distribution function P(r). A description of the |
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9 | # technique can be found elsewhere [1-5]. The module is useable as a |
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10 | # standalone application but its functionality is meant to be presented |
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11 | # to end-users through the user interface developed as part of the SAS |
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12 | # flagship application. |
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13 | # |
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14 | # Procedure: We will follow the procedure of Moore [1]. |
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15 | # |
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16 | # [1] P.B. Moore, J.Appl. Cryst (1980) 13, 168-175. |
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17 | # |
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18 | # [2] O. Glatter, J.Appl. Cryst (1977) 10, 415-421. |
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19 | # |
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20 | # [3] D.I. Svergun, J.Appl. Cryst (1991) 24, 485-492. |
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21 | # |
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22 | # [4] D.I. Svergun, J.Appl. Cryst (1992) 25, 495-503. |
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23 | # |
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24 | # [5] S. Hansen and J. Skov Pedersen, J.Appl. Cryst (1991) 24, 541-548. |
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25 | # |
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26 | ## \subsection class Class Diagram: |
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27 | # The following shows a partial class diagram with the main attributes |
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28 | # and methods of the invertor. |
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29 | # |
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30 | # \image html architecture.png |
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31 | # |
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32 | # \section install_sec Installation |
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33 | # |
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34 | # \subsection obtain Obtaining the Code |
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35 | # |
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36 | # The code is available here: |
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37 | # \verbatim |
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38 | #$ svn co svn://danse.us/sas/pr_inversion |
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39 | # \endverbatim |
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40 | # |
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41 | # \subsection depends External Dependencies |
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42 | # scipy, numpy |
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43 | # |
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44 | # \subsection build Building the code |
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45 | # The standard python package can be built with distutils. |
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46 | # \verbatim |
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47 | #$ python setup.py build |
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48 | #$ python setup.py install |
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49 | # \endverbatim |
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50 | # |
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51 | # |
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52 | # \subsection Tutorial |
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53 | # To create an inversion object: |
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54 | # \verbatim |
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55 | #from sas.pr.invertor import Invertor |
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56 | # invertor = Invertor() |
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57 | # \endverbatim |
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58 | # |
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59 | # To set the maximum distance between any two points: |
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60 | # \verbatim |
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61 | # invertor.d_max = 160.0 |
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62 | # \endverbatim |
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63 | # |
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64 | # To set the regularization constant: |
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65 | # \verbatim |
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66 | # invertor.alpha = 0.0007 |
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67 | # \endverbatim |
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68 | # |
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69 | # To set the q, I(q) and error on I(q): |
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70 | # \verbatim |
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71 | # invertor.x = q_vector |
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72 | # invertor.y = Iq_vector |
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73 | # invertor.err = dIq_vector |
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74 | # \endverbatim |
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75 | # |
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76 | # To perform the inversion. In this example, we choose |
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77 | # a P(r) expension wit 10 base functions. |
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78 | # \verbatim |
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79 | # c_out, c_cov = invertor.invert(10) |
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80 | # \endverbatim |
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81 | # The c_out and c_cov are the set of coefficients and the covariance |
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82 | # matrix for those coefficients, respectively. |
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83 | # |
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84 | # To get P(r): |
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85 | # \verbatim |
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86 | # r = 10.0 |
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87 | # pr = invertor.pr(c_out, r) |
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88 | # \endverbatim |
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89 | # Alternatively, one can get P(r) with the error on P(r): |
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90 | # \verbatim |
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91 | # r = 10.0 |
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92 | # pr, dpr = invertor.pr_err(c_out, c_cov, r) |
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93 | # \endverbatim |
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94 | # |
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95 | # To get the output I(q) from the set of coefficients found: |
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96 | # \verbatim |
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97 | # q = 0.001 |
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98 | # iq = invertor.iq(c_out, q) |
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99 | # \endverbatim |
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100 | # |
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101 | # Examples are available as unit tests under sas.pr_inversion.test. |
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102 | # |
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103 | # \section help_sec Contact Info |
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104 | # Code and Documentation produced as part of the DANSE project. |
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105 | |
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106 | __author__ = 'University of Tennessee' |
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