1 | from asap._asap import sdtable |
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2 | from numarray import ones |
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3 | import sys |
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4 | |
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5 | class scantable(sdtable): |
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6 | """ |
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7 | The ASAP container for scans |
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8 | """ |
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9 | def functions(self): |
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10 | return ['copy','get_scan','summary','rms','set_unit','create_mask'] |
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11 | |
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12 | def __init__(self, filename): |
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13 | """ |
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14 | Create a scantable from a saved one or make a reference |
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15 | Parameters: |
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16 | filename: the name of an asap table on disk, or |
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17 | [advanced] a refernce to an existing |
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18 | scantable |
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19 | """ |
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20 | sdtable.__init__(self, filename) |
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21 | self._unit = 'channel' |
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22 | |
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23 | def copy(self): |
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24 | """ |
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25 | Return a copy of this scantable. |
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26 | Parameters: |
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27 | |
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28 | Example: |
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29 | copiedscan = scan.copy() |
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30 | """ |
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31 | sd = sdtable._copy(self) |
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32 | return scantable(sd) |
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33 | def get_scan(self, scanid=None): |
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34 | """ |
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35 | Return a specific scan (by scanno) or collection of scans (by |
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36 | source name) in a new scantable. |
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37 | Parameters: |
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38 | scanid: a scanno or a source name |
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39 | Example: |
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40 | scan.getscan('323p459') |
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41 | # gets all scans containing the source '323p459' |
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42 | """ |
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43 | if scanid is None: |
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44 | print "Please specify a scan no or name to retrieve from the scantable" |
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45 | try: |
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46 | if type(scanid) is str: |
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47 | s = sdtable.getsource(self,scanid) |
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48 | return scantable(s) |
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49 | elif type(scanid) is int: |
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50 | s = sdtable.getscan(self,scanid) |
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51 | return scantable(s) |
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52 | except RuntimeError: |
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53 | print "Couldn't find any match." |
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54 | |
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55 | def __str__(self): |
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56 | return sdtable.summary(self) |
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57 | |
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58 | def summary(self,filename=None): |
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59 | """ |
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60 | Print a summary of the contents of this scantable. |
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61 | Parameters: |
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62 | filename: the name of a file to write the putput to |
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63 | Default - no file output |
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64 | """ |
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65 | info = sdtable.summary(self) |
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66 | if filename is not None: |
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67 | data = open(filename, 'w') |
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68 | data.write(info) |
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69 | data.close() |
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70 | print info |
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71 | |
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72 | def set_selection(self, thebeam=0,theif=0,thepol=0): |
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73 | """ |
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74 | Set the spectrum for individual operations. |
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75 | Parameters: |
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76 | thebeam,theif,thepol: a number |
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77 | Example: |
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78 | scan.set_selection(0,0,1) |
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79 | pol1rms = scan.rms(all=False) # returns rms for beam=0 |
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80 | # if=0, pol=1 |
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81 | """ |
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82 | self.setbeam(thebeam) |
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83 | self.setpol(thepol) |
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84 | self.setif(theif) |
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85 | return |
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86 | |
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87 | def get_selection(self): |
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88 | i = self.getbeam() |
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89 | j = self.getif() |
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90 | k = self.getpol() |
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91 | out = 'Beam=%d IF=%d Pol=%d '% (i,j,k) |
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92 | print out |
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93 | return i,j,k |
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94 | |
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95 | def rms(self,mask=None, all=True): |
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96 | """ |
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97 | Determine the root mean square of the current beam/if/pol |
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98 | Takes a 'mask' as an optional parameter to specify which |
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99 | channels should be excluded. |
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100 | Parameters: |
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101 | mask: an optional mask specifying where the rms |
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102 | should be determined. |
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103 | all: optional flag to show all or a selected |
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104 | spectrum of Beam/IF/Pol |
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105 | |
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106 | Example: |
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107 | scan.setuint('channel') |
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108 | msk = scan.create_mask([100,200],[500,600]) |
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109 | scan.rms(mask=m) |
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110 | """ |
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111 | from asap._asap import rms as _rms |
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112 | if mask == None: |
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113 | mask = ones(self.nchan()) |
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114 | if all: |
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115 | out = '' |
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116 | tmp = [] |
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117 | for i in range(self.nbeam()): |
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118 | self.setbeam(i) |
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119 | for j in range(self.nif()): |
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120 | self.setif(j) |
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121 | for k in range(self.npol()): |
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122 | self.setpol(k) |
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123 | rmsval = _rms(self,mask) |
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124 | tmp.append(rmsval) |
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125 | out += 'Beam[%d], IF[%d], Pol[%d] = %3.3f\n' % (i,j,k,rmsval) |
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126 | print out |
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127 | return tmp |
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128 | |
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129 | else: |
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130 | i = self.getbeam() |
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131 | j = self.getif() |
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132 | k = self.getpol() |
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133 | rmsval = _rms(self,mask) |
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134 | out = 'Beam[%d], IF[%d], Pol[%d] = %3.3f' % (i,j,k,rmsval) |
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135 | print out |
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136 | return rmsval |
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137 | |
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138 | def get_tsys(self, all=True): |
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139 | if all: |
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140 | tmp = [] |
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141 | out = '' |
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142 | for i in range(self.nbeam()): |
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143 | self.setbeam(i) |
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144 | for j in range(self.nif()): |
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145 | self.setif(j) |
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146 | for k in range(self.npol()): |
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147 | self.setpol(k) |
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148 | ts = self.gettsys() |
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149 | tmp.append(ts) |
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150 | out += 'TSys: Beam[%d], IF[%d], Pol[%d] = %3.3f\n' % (i,j,k,ts) |
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151 | print out |
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152 | return tmp |
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153 | else: |
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154 | i = self.getbeam() |
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155 | j = self.getif() |
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156 | k = self.getpol() |
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157 | ts = self.gettsys() |
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158 | out = 'TSys: Beam[%d], IF[%d], Pol[%d] = %3.3f' % (i,j,k,ts) |
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159 | print out |
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160 | return ts |
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161 | |
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162 | def set_unit(self, unit='channel'): |
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163 | """ |
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164 | Set the unit for all following operations on this scantable |
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165 | Parameters: |
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166 | unit: optional unit, default is 'channel' |
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167 | one of 'GHz','MHz','km/s','channel' |
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168 | """ |
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169 | units = ['GHz','MHz','km/s','channel','pixel',''] |
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170 | if unit in units: |
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171 | if unit in ['','pixel']: |
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172 | unit = 'channel' |
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173 | self._unit = unit |
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174 | else: |
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175 | print "Invalid unit given, please use one of:" |
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176 | print units |
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177 | |
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178 | def create_mask(self, *args): |
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179 | """ |
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180 | Compute and return a mask based on [min,max] windows. |
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181 | Parameters: |
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182 | [min,max],[min2,max2],... |
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183 | Pairs of start/end points specifying the regions |
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184 | to be masked |
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185 | Example: |
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186 | scan.setunit('channel') |
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187 | msk = scan.set_mask([400,500],[800,900]) |
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188 | masks the regions between 400 and 500 |
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189 | and 800 and 900 in the unit 'channel' |
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190 | """ |
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191 | print "The current mask window unit is", self._unit |
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192 | n = self.nchan() |
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193 | if self._unit == 'channel': |
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194 | data = range(n) |
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195 | else: |
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196 | data = self.getabscissa(unit=self._unit) |
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197 | msk = ones(n) |
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198 | for window in args: |
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199 | if (len(window) != 2 or window[0] > window[1] ): |
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200 | print "A window needs to be defined as [min,max]" |
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201 | return |
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202 | for i in range(n): |
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203 | if data[i] > window[0] and data[i] < window[1]: |
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204 | msk[i] = 0 |
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205 | return msk |
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206 | def set_restfrequencies(self, freqs, unit='Hz'): |
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207 | """ |
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208 | Set the restfrequency(s) for this scantable. |
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209 | Parameters: |
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210 | freqs: one or more frequencies |
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211 | unit: optional 'unit', default 'Hz' |
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212 | Example: |
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213 | scan.set_restfrequencies([1000000000.0]) |
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214 | """ |
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215 | self.setrestfreqs(freqs, unit) |
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216 | return |
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217 | |
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218 | def flag_spectrum(self, thebeam, theif, thepol): |
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219 | """ |
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220 | This flags a selected spectrum in the scan 'for good'. |
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221 | USE WITH CARE - not reversible. |
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222 | Use masks for non-permanent exclusion of channels. |
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223 | Parameters: |
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224 | thebeam,theif,thepol: all have to be explicitly |
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225 | specified |
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226 | Example: |
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227 | scan.flag_spectrum(0,0,1) |
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228 | flags the spectrum for Beam=0, IF=0, Pol=1 |
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229 | """ |
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230 | if (thebeam < self.nbeam() and theif < self.nif() and thepol < self.npol()): |
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231 | stable.setbeam(thebeam) |
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232 | stable.setif(theif) |
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233 | stable.setpol(thepol) |
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234 | stable._flag(self) |
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235 | else: |
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236 | print "Please specify a valid (Beam/IF/Pol)" |
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237 | return |
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