1 | from asap._asap import sdreader |
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2 | |
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3 | class reader(sdreader): |
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4 | """ |
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5 | This class allows the user to import single dish files |
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6 | (rpfits,sdfits,ms). |
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7 | The reader reads in integrations from the file and reamins at |
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8 | the fileposition afterwards. |
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9 | Available functions are: |
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10 | |
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11 | read(integrations) |
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12 | summary CURRENTLY DISABLED |
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13 | |
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14 | Example: |
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15 | r = reader('/tmp/P389.rpf') |
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16 | scans r.read() # reads in the complete file into 'scans' |
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17 | print scans # summarises the contents |
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18 | del r # destroys the reader |
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19 | |
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20 | IMPORTANT: Due to limitations in the rpfits library, only one reader |
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21 | can be created at a time. |
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22 | r = reader('XYZ.rpf') |
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23 | r2 = reader('ABC.rpf') |
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24 | is NOT possible. This is a limitation affecting |
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25 | rpfits ONLY. |
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26 | """ |
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27 | |
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28 | def __init__(self, filename, unit=None, theif=None, thebeam=None): |
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29 | self.unit = unit |
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30 | """ |
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31 | Parameters: |
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32 | filename: the name of an rpfits/sdfits/ms file on disk |
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33 | unit: brightness unit; must be consistent with K or Jy. |
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34 | The default is that a unit is set depending on |
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35 | the telescope. Setting this over-rides that choice. |
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36 | theif: select a specific IF (default is all) |
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37 | thebeam: select a specific beam (default is all) |
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38 | Example: |
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39 | r = reader('/tmp/2001-09-01_0332_P363.rpf', theif=2) |
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40 | """ |
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41 | if theif is None: |
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42 | theif = -1 |
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43 | if thebeam is None: |
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44 | thebeam = -1 |
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45 | from os.path import expandvars |
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46 | filename = expandvars(filename) |
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47 | sdreader.__init__(self, filename, theif, thebeam) |
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48 | |
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49 | def read(self,integrations=None): |
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50 | """ |
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51 | Reads in an returns a specified sequence of integrations. |
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52 | If no list is given all integrations a read in. |
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53 | Parameters: |
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54 | integrations: a 'range' of integration numbers, e.g. |
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55 | range(100) or [0,1,2,3,4,10,11,100] |
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56 | If not given (default) all integrations |
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57 | are read in |
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58 | Example: |
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59 | r.read([0,1,2,3,4]) # reads in the first 5 integatrions |
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60 | # NOT scans |
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61 | r.read(range(100)) # read in the first 100 integrations |
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62 | """ |
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63 | from asap import scantable |
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64 | if integrations is None: |
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65 | integrations = [-1] |
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66 | print "Reading integrations from disk..." |
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67 | sdreader._read(self,integrations) |
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68 | tbl = sdreader._getdata(self) |
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69 | sdreader._reset(self) # reset to the beginning of the file |
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70 | if self.unit is not None: |
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71 | tbl.set_fluxunit(self.unit) |
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72 | return scantable(tbl) |
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73 | |
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74 | def summary(self, name=None): |
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75 | """ |
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76 | Print a summary of all scans/integrations. This reads through the |
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77 | whole file once. |
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78 | Parameters: |
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79 | None |
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80 | Example: |
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81 | r.summary() |
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82 | """ |
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83 | sdreader._reset(self) |
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84 | sdreader._read(self,[-1]) |
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85 | from asap import scantable |
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86 | tbl = scantable(sdreader._getdata(self)) |
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87 | sdreader._reset(self) |
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88 | tbl.summary(name) |
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89 | return |
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90 | ## def reset(self): |
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91 | ## """ |
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92 | ## [Advanced use] |
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93 | ## Reset to the beginning of the file. |
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94 | ## Parameters: |
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95 | ## none |
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96 | ## Examples: |
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97 | ## r = reader('xyz.sdfits') |
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98 | ## scans0 = r.read(range(10)) |
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99 | ## r.reset() |
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100 | ## scans1 = r.read(range(5,15)) |
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101 | ## # produces 2 scatables one containing integrations(rows) 0-9 |
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102 | ## # and a second one with rows 5-14 |
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103 | ## """ |
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104 | ## sdreader._reset(self) |
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105 | |
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