1 | import os, shutil |
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2 | import numpy |
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3 | import numpy.fft as FFT |
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4 | import math |
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5 | |
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6 | from asap.scantable import scantable |
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7 | from asap.parameters import rcParams |
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8 | from asap.logging import asaplog, asaplog_post_dec |
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9 | from asap.selector import selector |
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10 | from asap.asapgrid import asapgrid2 |
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11 | from asap._asap import SBSeparator |
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12 | |
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13 | class sbseparator: |
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14 | """ |
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15 | The sbseparator class is defined to separate SIGNAL and IMAGE |
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16 | sideband spectra observed by frequency-switching technique. |
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17 | It also helps supressing emmission of IMAGE sideband. |
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18 | *** WARNING *** THIS MODULE IS EXPERIMENTAL |
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19 | Known issues: |
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20 | - Frequencies of IMAGE sideband cannot be reconstructed from |
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21 | information in scantable in sideband sparation. Frequency |
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22 | setting of SIGNAL sideband is stored in output table for now. |
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23 | - Flag information (stored in FLAGTRA) is ignored. |
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24 | |
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25 | Example: |
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26 | # Create sideband separator instance whith 3 input data |
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27 | sbsep = sbseparator(['test1.asap', 'test2.asap', 'test3.asap']) |
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28 | # Set reference IFNO and tolerance to select data |
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29 | sbsep.set_frequency(5, 30, frame='TOPO') |
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30 | # Set direction tolerance to select data in unit of radian |
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31 | sbsep.set_dirtol(1.e-5) |
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32 | # Set rejection limit of solution |
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33 | sbsep.set_limit(0.2) |
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34 | # Solve image sideband as well |
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35 | sbsep.set_both(True) |
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36 | # Invoke sideband separation |
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37 | sbsep.separate('testout.asap', overwrite = True) |
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38 | """ |
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39 | def __init__(self, infiles): |
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40 | self._separator = SBSeparator(infiles) |
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41 | |
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42 | |
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43 | def set_frequency(self, baseif, freqtol, frame=""): |
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44 | """ |
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45 | Set IFNO and frequency tolerance to select data to process. |
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46 | |
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47 | Parameters: |
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48 | - reference IFNO to process in the first table in the list |
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49 | - frequency tolerance from reference IF to select data (string) |
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50 | frame : frequency frame to select IF |
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51 | """ |
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52 | if type(freqtol) in (float, int): |
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53 | freqtol = str(freqtol) |
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54 | elif isinstance(freqtol, dict): |
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55 | try: |
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56 | freqtol = str(freqtol['value']) + freqtol['unit'] |
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57 | except: |
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58 | raise ValueError, "Invalid frequency tolerance." |
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59 | self._separator.set_freq(baseif, freqtol, frame) |
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60 | |
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61 | |
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62 | def set_dirtol(self, dirtol=["2arcsec", "2arcsec"]): |
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63 | """ |
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64 | Set tolerance of direction to select data |
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65 | """ |
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66 | if isinstance(dirtol, str): |
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67 | dirtol = [dirtol] |
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68 | |
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69 | self._separator.set_dirtol(dirtol) |
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70 | |
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71 | |
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72 | def set_shift(self, imageshift=[]): |
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73 | """ |
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74 | Set shift mode and channel shift of image band. |
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75 | |
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76 | imageshift : a list of number of channels shifted in image |
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77 | side band of each scantable. |
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78 | If the shifts are not set, they are assumed to be |
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79 | equal to those of signal side band, but in opposite |
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80 | direction as usual by LO1 offsetting of DSB receivers. |
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81 | """ |
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82 | if not imageshift: |
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83 | imageshift = [] |
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84 | self._separator.set_shift(imageshift) |
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85 | |
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86 | |
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87 | @asaplog_post_dec |
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88 | def set_both(self, flag=False): |
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89 | """ |
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90 | Resolve both image and signal sideband when True. |
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91 | """ |
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92 | self._separator.solve_both(flag) |
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93 | if flag: |
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94 | asaplog.push("Both signal and image sidebands will be solved and stored in separate tables.") |
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95 | else: |
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96 | asaplog.push("Only signal sideband will be solved and stored in an table.") |
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97 | |
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98 | @asaplog_post_dec |
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99 | def set_limit(self, threshold=0.2): |
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100 | """ |
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101 | Set rejection limit of solution. |
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102 | """ |
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103 | self._separator.set_limit(threshold) |
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104 | |
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105 | |
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106 | @asaplog_post_dec |
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107 | def set_solve_other(self, flag=False): |
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108 | """ |
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109 | Calculate spectra by subtracting the solution of the other sideband |
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110 | when True. |
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111 | """ |
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112 | self._separator.subtract_other(flag) |
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113 | if flag: |
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114 | asaplog.push("Expert mode: solution are obtained by subtraction of the other sideband.") |
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115 | |
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116 | |
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117 | def set_lo1(self, lo1, frame="TOPO", reftime=-1, refdir=""): |
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118 | """ |
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119 | Set LO1 frequency to calculate frequency of image sideband. |
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120 | |
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121 | lo1 : LO1 frequency |
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122 | frame : the frequency frame of LO1 |
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123 | reftime : the reference time used in frequency frame conversion. |
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124 | refdir : the reference direction used in frequency frame conversion. |
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125 | """ |
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126 | self._separator.set_lo1(lo1, frame, reftime, refdir) |
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127 | |
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128 | |
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129 | def set_lo1root(self, name): |
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130 | """ |
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131 | Set MS name which stores LO1 frequency of signal side band. |
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132 | It is used to calculate frequency of image sideband. |
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133 | |
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134 | name : MS name which contains 'ASDM_SPECTRALWINDOW' and |
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135 | 'ASDM_RECEIVER' tables. |
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136 | """ |
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137 | self._separator.set_lo1root(name) |
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138 | |
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139 | @asaplog_post_dec |
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140 | def separate(self, outname="", overwrite=False): |
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141 | """ |
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142 | Invoke sideband separation. |
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143 | |
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144 | outname : a name of output scantable |
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145 | overwrite : overwrite existing table |
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146 | """ |
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147 | out_default = "sbseparated.asap" |
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148 | if len(outname) == 0: |
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149 | outname = out_default |
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150 | asaplog.post() |
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151 | asaplog.push("The output file name is not specified.") |
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152 | asaplog.push("Using default name '%s'" % outname) |
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153 | asaplog.post("WARN") |
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154 | |
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155 | if os.path.exists(outname): |
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156 | if overwrite: |
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157 | asaplog.push("removing the old file '%s'" % outname) |
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158 | shutil.rmtree(outname) |
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159 | else: |
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160 | asaplog.post() |
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161 | asaplog.push("Output file '%s' already exists." % outname) |
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162 | asaplog.post("ERROR") |
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163 | return False |
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164 | |
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165 | self._separator.separate(outname) |
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166 | |
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