1 | //#--------------------------------------------------------------------------- |
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2 | //# SDPol.cc: Polarimetric functionality |
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3 | //#--------------------------------------------------------------------------- |
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4 | //# Copyright (C) 2004 |
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5 | //# ATNF |
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6 | //# |
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7 | //# This program is free software; you can redistribute it and/or modify it |
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8 | //# under the terms of the GNU General Public License as published by the Free |
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9 | //# Software Foundation; either version 2 of the License, or (at your option) |
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10 | //# any later version. |
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11 | //# |
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12 | //# This program is distributed in the hope that it will be useful, but |
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13 | //# WITHOUT ANY WARRANTY; without even the implied warranty of |
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14 | //# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General |
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15 | //# Public License for more details. |
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16 | //# |
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17 | //# You should have received a copy of the GNU General Public License along |
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18 | //# with this program; if not, write to the Free Software Foundation, Inc., |
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19 | //# 675 Massachusetts Ave, Cambridge, MA 02139, USA. |
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20 | //# |
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21 | //# Correspondence concerning this software should be addressed as follows: |
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22 | //# Internet email: Malte.Marquarding@csiro.au |
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23 | //# Postal address: Malte Marquarding, |
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24 | //# Australia Telescope National Facility, |
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25 | //# P.O. Box 76, |
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26 | //# Epping, NSW, 2121, |
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27 | //# AUSTRALIA |
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28 | //# |
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29 | //# $Id: |
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30 | //#--------------------------------------------------------------------------- |
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31 | |
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32 | #include "SDPol.h" |
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33 | #include "SDDefs.h" |
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34 | |
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35 | #include <casa/Arrays/Array.h> |
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36 | #include <casa/Arrays/ArrayMath.h> |
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37 | #include <casa/Arrays/ArrayLogical.h> |
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38 | #include <casa/Containers/Record.h> |
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39 | #include <casa/BasicSL/Constants.h> |
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40 | #include <casa/BasicSL/String.h> |
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41 | #include <casa/Utilities/Assert.h> |
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42 | |
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43 | #include <tables/Tables/Table.h> |
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44 | #include <tables/Tables/ScalarColumn.h> |
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45 | #include <tables/Tables/ArrayColumn.h> |
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46 | #include <tables/Tables/ColumnDesc.h> |
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47 | #include <tables/Tables/TableRecord.h> |
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48 | #include <tables/Tables/DataManError.h> |
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49 | |
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50 | |
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51 | using namespace casa; |
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52 | using namespace asap; |
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53 | |
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54 | |
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55 | |
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56 | SDStokesEngine::SDStokesEngine (const String& outputColumnName, |
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57 | const String& inputColumnName) |
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58 | : BaseMappedArrayEngine<Float,Float> (outputColumnName, inputColumnName) |
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59 | {} |
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60 | |
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61 | |
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62 | SDStokesEngine::SDStokesEngine (const Record& spec) |
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63 | : BaseMappedArrayEngine<Float,Float> () |
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64 | { |
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65 | if (spec.isDefined("OUTPUTNAME") && spec.isDefined("INPUTNAME")) { |
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66 | setNames (spec.asString("OUTPUTNAME"), spec.asString("INPUTNAME")); |
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67 | } |
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68 | } |
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69 | |
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70 | SDStokesEngine::SDStokesEngine (const SDStokesEngine& that) |
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71 | : BaseMappedArrayEngine<Float,Float> (that) |
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72 | {} |
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73 | |
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74 | SDStokesEngine::~SDStokesEngine() |
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75 | {} |
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76 | |
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77 | |
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78 | DataManager* SDStokesEngine::clone() const |
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79 | { |
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80 | DataManager* dmPtr = new SDStokesEngine (*this); |
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81 | return dmPtr; |
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82 | } |
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83 | |
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84 | |
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85 | String SDStokesEngine::dataManagerType() const |
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86 | { |
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87 | return className(); |
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88 | } |
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89 | |
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90 | String SDStokesEngine::className() |
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91 | { |
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92 | return "SDStokesEngine"; |
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93 | } |
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94 | |
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95 | String SDStokesEngine::dataManagerName() const |
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96 | { |
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97 | return sourceName(); |
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98 | } |
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99 | |
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100 | Record SDStokesEngine::dataManagerSpec() const |
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101 | { |
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102 | Record spec; |
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103 | spec.define ("OUTPUTNAME", sourceName()); // Ger uses opposite meaning for source/target |
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104 | spec.define ("INPUTNAME", targetName()); |
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105 | return spec; |
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106 | } |
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107 | |
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108 | DataManager* SDStokesEngine::makeObject (const String&, const Record& spec) |
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109 | { |
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110 | DataManager* dmPtr = new SDStokesEngine(spec); |
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111 | return dmPtr; |
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112 | } |
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113 | |
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114 | |
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115 | void SDStokesEngine::registerClass() |
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116 | { |
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117 | DataManager::registerCtor (className(), makeObject); |
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118 | } |
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119 | |
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120 | |
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121 | void SDStokesEngine::create (uInt initialNrrow) |
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122 | { |
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123 | BaseMappedArrayEngine<Float,Float>::create (initialNrrow); |
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124 | } |
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125 | |
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126 | void SDStokesEngine::prepare() |
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127 | { |
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128 | BaseMappedArrayEngine<Float,Float>::prepare(); |
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129 | } |
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130 | |
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131 | Bool SDStokesEngine::canAccessArrayColumnCells (Bool& reask) const |
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132 | { |
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133 | reask = False; |
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134 | return True; |
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135 | } |
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136 | |
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137 | |
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138 | void SDStokesEngine::getArray (uInt rownr, Array<Float>& output) |
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139 | { |
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140 | Array<Float> input; |
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141 | roColumn().get(rownr, input); |
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142 | // |
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143 | computeOnGet (output, input); |
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144 | } |
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145 | |
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146 | void SDStokesEngine::putArray (uInt rownr, const Array<Float>& input) |
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147 | { |
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148 | throw(AipsError("This Virtual Column is not writable")); |
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149 | } |
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150 | |
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151 | |
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152 | |
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153 | |
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154 | |
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155 | IPosition SDStokesEngine::shape (uInt rownr) |
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156 | { |
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157 | IPosition inputShape = roColumn().shape (rownr); |
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158 | return findOutputShape(inputShape); |
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159 | } |
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160 | |
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161 | |
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162 | |
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163 | void SDStokesEngine::computeOnGet(Array<Float>& output, |
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164 | const Array<Float>& input) |
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165 | // |
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166 | // array of shape (nBeam,nIF,nPol,nChan) |
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167 | // |
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168 | // We use the scaling convention I=(XX+YY) |
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169 | // |
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170 | { |
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171 | |
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172 | // Checks |
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173 | |
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174 | const uInt nDim = input.ndim(); |
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175 | AlwaysAssert(nDim==4,AipsError); |
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176 | AlwaysAssert(output.ndim()==4,AipsError); |
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177 | // |
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178 | const IPosition inputShape = input.shape(); |
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179 | const uInt polAxis = asap::PolAxis; |
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180 | const uInt nPol = inputShape(polAxis); |
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181 | AlwaysAssert(nPol==1 || nPol==2 || nPol==4, AipsError); |
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182 | |
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183 | // The silly Array slice operator does not give me back |
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184 | // a const reference so have to caste it away |
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185 | |
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186 | Array<Float>& input2 = const_cast<Array<Float>&>(input); |
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187 | |
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188 | // Slice coordnates |
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189 | |
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190 | IPosition start(nDim,0); |
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191 | IPosition end(input.shape()-1); |
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192 | |
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193 | // Generate Slices |
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194 | |
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195 | start(polAxis) = 0; |
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196 | end(polAxis) = 0; |
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197 | Array<Float> C1 = input2(start,end); // Input : C1 |
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198 | // |
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199 | start(polAxis) = 0; |
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200 | end(polAxis) = 0; |
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201 | Array<Float> I = output(start,end); // Output : I |
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202 | // |
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203 | if (nPol==1) { |
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204 | I = Float(2.0)*C1; |
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205 | return; |
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206 | } |
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207 | // |
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208 | start(polAxis) = 1; |
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209 | end(polAxis) = 1; |
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210 | Array<Float> C2 = input2(start,end); // Input : C1 |
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211 | // |
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212 | I = C1 + C2; |
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213 | if (nPol <= 2) return; |
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214 | // |
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215 | start(polAxis) = 2; |
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216 | end(polAxis) = 2; |
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217 | Array<Float> C3 = input2(start,end); // Input : C3 |
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218 | // |
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219 | start(polAxis) = 3; |
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220 | end(polAxis) = 3; |
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221 | Array<Float> C4 = input2(start,end); // Input : C4 |
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222 | // |
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223 | start(polAxis) = 1; |
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224 | end(polAxis) = 1; |
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225 | Array<Float> Q = output(start,end); // Output : Q |
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226 | Q = C1 - C2; |
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227 | // |
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228 | start(polAxis) = 2; |
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229 | end(polAxis) = 2; |
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230 | Array<Float> U = output(start,end); // Output : U |
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231 | U = Float(2.0)*C3; |
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232 | // |
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233 | start(polAxis) = 3; |
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234 | end(polAxis) = 3; |
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235 | Array<Float> V = output(start,end); // Output : V |
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236 | V = Float(2.0)*C4; |
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237 | } |
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238 | |
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239 | |
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240 | |
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241 | IPosition SDStokesEngine::findOutputShape (const IPosition& inputShape) const |
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242 | { |
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243 | uInt axis = 2; |
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244 | uInt nPol = inputShape(axis); |
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245 | IPosition outputShape = inputShape; |
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246 | if (nPol==1) { |
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247 | outputShape(axis) = 1; // XX -> I |
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248 | } else if (nPol==2) { |
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249 | outputShape(axis) = 1; // XX YY -> I |
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250 | } else if (nPol==4) { |
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251 | outputShape(axis) = 4; // XX YY R(XY) I(XY) -> I Q U V |
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252 | } |
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253 | return outputShape; |
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254 | } |
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255 | |
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256 | |
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257 | |
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258 | // SDPolUtil |
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259 | |
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260 | Array<Float> SDPolUtil::polarizedIntensity (const Array<Float>& Q, |
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261 | const Array<Float>& U) |
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262 | { |
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263 | Array<Float> t1 = pow(Q,Double(2.0)); |
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264 | Array<Float> t2 = pow(U,Double(2.0)); |
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265 | return sqrt(t1+t2); |
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266 | } |
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267 | |
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268 | |
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269 | Array<Float> SDPolUtil::positionAngle (const Array<Float>& Q, |
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270 | const Array<Float>& U) |
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271 | { |
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272 | return Float(180.0/C::pi/2.0)*atan2(Q,U); // Degrees |
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273 | } |
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274 | |
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275 | |
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276 | void SDPolUtil::rotateXYPhase (Array<Float>& C3, |
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277 | Array<Float>& C4, |
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278 | Float phase) |
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279 | { |
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280 | Float cosVal = cos(C::pi/180.0*phase); |
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281 | Float sinVal = sin(C::pi/180.0*phase); |
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282 | // |
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283 | C3 = C3*cosVal - C4*sinVal; |
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284 | C4 = C3*sinVal + C4*cosVal; |
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285 | } |
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286 | |
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287 | |
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288 | |
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289 | Array<Float> SDPolUtil::getStokesSlice (Array<Float>& in, const IPosition& start, |
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290 | const IPosition& end, const String& stokes) |
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291 | { |
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292 | IPosition s(start); |
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293 | IPosition e(end); |
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294 | // |
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295 | if (stokes=="I") { |
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296 | s(asap::PolAxis) = 0; |
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297 | e(asap::PolAxis) = 0; |
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298 | } else if (stokes=="Q") { |
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299 | s(asap::PolAxis) = 1; |
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300 | e(asap::PolAxis) = 1; |
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301 | } else if (stokes=="U") { |
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302 | s(asap::PolAxis) = 2; |
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303 | e(asap::PolAxis) = 2; |
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304 | } else if (stokes=="V") { |
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305 | s(asap::PolAxis) = 3; |
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306 | e(asap::PolAxis) = 3; |
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307 | } |
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308 | // |
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309 | return in(s,e); |
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310 | } |
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311 | |
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312 | |
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313 | Array<Float> SDPolUtil::circularPolarizationFromStokes (Array<Float>& I, |
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314 | Array<Float>& V, |
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315 | Bool doRR) |
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316 | { |
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317 | if (doRR) { |
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318 | return Float(0.5)*(I+V); |
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319 | } else { |
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320 | return Float(0.5)*(I-V); |
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321 | } |
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322 | } |
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323 | |
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324 | Array<Bool> SDPolUtil::stokesMask (Array<Bool> rawFlags, |
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325 | Bool doLinear) |
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326 | // |
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327 | // Generate mask for each Stokes parameter from the |
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328 | // raw flags. This is a lot of computational work and may |
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329 | // not be worth the effort. |
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330 | // |
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331 | { |
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332 | IPosition shapeIn = rawFlags.shape(); |
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333 | uInt nPol = shapeIn(asap::PolAxis); |
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334 | const uInt nDim = shapeIn.nelements(); |
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335 | Array<Bool> stokesFlags; |
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336 | // |
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337 | IPosition start(nDim,0); |
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338 | IPosition end(shapeIn-1); |
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339 | IPosition shapeOut = shapeIn; |
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340 | // |
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341 | if (doLinear) { |
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342 | if (nPol==1) { |
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343 | stokesFlags.resize(shapeOut); |
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344 | stokesFlags = rawFlags; |
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345 | } else if (nPol==2 || nPol==4) { |
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346 | |
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347 | // Set shape of output array |
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348 | |
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349 | if (nPol==2) { |
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350 | shapeOut(asap::PolAxis) = 1; |
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351 | } else { |
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352 | shapeOut(asap::PolAxis) = 4; |
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353 | } |
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354 | stokesFlags.resize(shapeOut); |
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355 | |
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356 | // Get reference slices and assign/compute |
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357 | |
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358 | start(asap::PolAxis) = 0; |
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359 | end(asap::PolAxis) = 0; |
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360 | Array<Bool> M1In = rawFlags(start,end); |
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361 | // |
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362 | start(asap::PolAxis) = 1; |
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363 | end(asap::PolAxis) = 1; |
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364 | Array<Bool> M2In = rawFlags(start,end); |
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365 | // |
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366 | start(asap::PolAxis) = 0; |
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367 | end(asap::PolAxis) = 0; |
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368 | Array<Bool> M1Out = stokesFlags(start,end); |
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369 | M1Out = M1In && M2In; // I |
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370 | // |
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371 | if (nPol==4) { |
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372 | start(asap::PolAxis) = 2; |
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373 | end(asap::PolAxis) = 2; |
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374 | Array<Bool> M3In = rawFlags(start,end); |
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375 | // |
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376 | start(asap::PolAxis) = 3; |
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377 | end(asap::PolAxis) = 3; |
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378 | Array<Bool> M4In = rawFlags(start,end); |
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379 | // |
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380 | start(asap::PolAxis) = 1; |
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381 | end(asap::PolAxis) = 1; |
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382 | Array<Bool> M2Out = stokesFlags(start,end); |
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383 | M2Out = M1Out; // Q |
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384 | // |
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385 | start(asap::PolAxis) = 2; |
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386 | end(asap::PolAxis) = 2; |
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387 | Array<Bool> M3Out = stokesFlags(start,end); |
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388 | M3Out = M3In; // U |
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389 | // |
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390 | start(asap::PolAxis) = 3; |
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391 | end(asap::PolAxis) = 3; |
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392 | Array<Bool> M4Out = stokesFlags(start,end); |
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393 | M4Out = M4In; // V |
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394 | } |
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395 | } else { |
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396 | throw(AipsError("Can only handle 1,2 or 4 polarizations")); |
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397 | } |
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398 | } else { |
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399 | throw (AipsError("Only implemented for Linear polarizations")); |
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400 | } |
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401 | // |
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402 | return stokesFlags; |
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403 | } |
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404 | |
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405 | Stokes::StokesTypes SDPolUtil::convertStokes(Int val, Bool toStokes, Bool linear) |
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406 | { |
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407 | Stokes::StokesTypes stokes = Stokes::Undefined; |
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408 | if (toStokes) { |
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409 | if (val==0) { |
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410 | stokes = Stokes::I; |
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411 | } else if (val==1) { |
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412 | stokes = Stokes::Q; |
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413 | } else if (val==2) { |
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414 | stokes = Stokes::U; |
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415 | } else if (val==3) { |
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416 | stokes = Stokes::V; |
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417 | } |
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418 | } else if (linear) { |
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419 | if (val==0) { |
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420 | stokes = Stokes::XX; |
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421 | } else if (val==1) { |
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422 | stokes = Stokes::YY; |
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423 | } else if (val==2) { |
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424 | stokes = Stokes::XY; // Real(XY) |
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425 | } else if (val==3) { |
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426 | stokes = Stokes::XY; // Imag(XY) |
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427 | } |
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428 | } else { |
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429 | if (val==0) { |
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430 | stokes = Stokes::RR; |
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431 | } else if (val==1) { |
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432 | stokes = Stokes::LL; |
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433 | } else if (val==2) { |
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434 | stokes = Stokes::RL; |
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435 | } else if (val==3) { |
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436 | stokes = Stokes::RL; |
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437 | } |
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438 | } |
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439 | // |
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440 | return stokes; |
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441 | } |
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