1 | """ |
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2 | This software was developed by the University of Tennessee as part of the |
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3 | Distributed Data Analysis of Neutron Scattering Experiments (DANSE) |
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4 | project funded by the US National Science Foundation. |
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5 | |
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6 | See the license text in license.txt |
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7 | |
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8 | copyright 2008, University of Tennessee |
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9 | """ |
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10 | |
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11 | import numpy |
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12 | import os |
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13 | from DataLoader.data_info import Data1D |
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14 | |
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15 | class Reader: |
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16 | """ |
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17 | Class to load ascii files (2 or 3 columns) |
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18 | """ |
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19 | ## File type |
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20 | type = ["ASCII files (*.txt)|*.txt", |
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21 | "ASCII files (*.dat)|*.dat"] |
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22 | ## List of allowed extensions |
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23 | ext=['.txt', '.TXT', '.dat', '.DAT'] |
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24 | |
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25 | def read(self, path): |
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26 | """ |
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27 | Load data file |
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28 | |
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29 | @param path: file path |
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30 | @return: Data1D object, or None |
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31 | @raise RuntimeError: when the file can't be opened |
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32 | @raise ValueError: when the length of the data vectors are inconsistent |
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33 | """ |
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34 | if os.path.isfile(path): |
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35 | basename = os.path.basename(path) |
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36 | root, extension = os.path.splitext(basename) |
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37 | if extension.lower() in self.ext: |
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38 | try: |
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39 | input_f = open(path,'r') |
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40 | except : |
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41 | raise RuntimeError, "ascii_reader: cannot open %s" % path |
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42 | buff = input_f.read() |
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43 | lines = buff.split('\n') |
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44 | x = numpy.zeros(0) |
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45 | y = numpy.zeros(0) |
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46 | dy = numpy.zeros(0) |
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47 | output = Data1D(x, y, dy=dy) |
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48 | self.filename = output.filename = basename |
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49 | |
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50 | # The first good line of data will define whether |
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51 | # we have 2-column or 3-column ascii |
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52 | has_error = None |
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53 | |
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54 | for line in lines: |
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55 | toks = line.split() |
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56 | try: |
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57 | _x = float(toks[0]) |
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58 | _y = float(toks[1]) |
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59 | |
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60 | # If we have an extra token, check |
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61 | # whether it can be interpreted as a |
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62 | # third column. |
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63 | _dy = None |
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64 | if len(toks)>2: |
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65 | try: |
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66 | _dy = float(toks[2]) |
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67 | except: |
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68 | # The third column is not a float, skip it. |
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69 | pass |
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70 | |
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71 | # If we haven't set the 3rd column |
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72 | # flag, set it now. |
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73 | if has_error == None: |
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74 | has_error = False if _dy == None else True |
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75 | |
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76 | x = numpy.append(x, _x) |
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77 | y = numpy.append(y, _y) |
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78 | if has_error == True: |
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79 | dy = numpy.append(dy, _dy) |
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80 | |
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81 | except: |
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82 | # Couldn't parse this line, skip it |
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83 | pass |
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84 | |
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85 | |
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86 | # Sanity check |
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87 | if has_error == True and not len(y) == len(dy): |
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88 | raise ValueError, "ascii_reader: y and dy have different length" |
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89 | |
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90 | # If the data length is zero, consider this as |
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91 | # though we were not able to read the file. |
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92 | if len(x)==0: |
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93 | raise ValueError, "ascii_reader: could not load file" |
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94 | |
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95 | output.x = x |
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96 | output.y = y |
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97 | output.dy = dy if has_error == True else None |
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98 | output.xaxis("\\rm{Q}", 'A^{-1}') |
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99 | output.yaxis("\\rm{I(Q)}","cm^{-1}") |
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100 | |
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101 | |
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102 | return output |
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103 | else: |
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104 | raise RuntimeError, "%s is not a file" % path |
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105 | return None |
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106 | |
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107 | if __name__ == "__main__": |
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108 | reader = Reader() |
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109 | #print reader.read("../test/test_3_columns.txt") |
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110 | print reader.read("../test/empty.txt") |
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111 | |
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112 | |
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113 | |
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