1 | // ----------------------------------------------------------------------- |
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2 | // position_related.cc: General utility functions related to WCS positions |
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3 | // ----------------------------------------------------------------------- |
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4 | // Copyright (C) 2006, Matthew Whiting, ATNF |
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5 | // |
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6 | // This program is free software; you can redistribute it and/or modify it |
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7 | // under the terms of the GNU General Public License as published by the |
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8 | // Free Software Foundation; either version 2 of the License, or (at your |
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9 | // option) any later version. |
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10 | // |
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11 | // Duchamp is distributed in the hope that it will be useful, but WITHOUT |
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12 | // ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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13 | // FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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14 | // for more details. |
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15 | // |
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16 | // You should have received a copy of the GNU General Public License |
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17 | // along with Duchamp; if not, write to the Free Software Foundation, |
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18 | // Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA |
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19 | // |
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20 | // Correspondence concerning Duchamp may be directed to: |
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21 | // Internet email: Matthew.Whiting [at] atnf.csiro.au |
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22 | // Postal address: Dr. Matthew Whiting |
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23 | // Australia Telescope National Facility, CSIRO |
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24 | // PO Box 76 |
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25 | // Epping NSW 1710 |
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26 | // AUSTRALIA |
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27 | // ----------------------------------------------------------------------- |
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28 | #include <iostream> |
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29 | #include <sstream> |
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30 | #include <iomanip> |
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31 | #include <string> |
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32 | #include <stdlib.h> |
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33 | #include <math.h> |
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34 | #include <duchamp/Utils/utils.hh> |
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35 | |
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36 | using std::setw; |
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37 | using std::setfill; |
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38 | using std::setprecision; |
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39 | |
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40 | std::string getIAUNameEQ(double ra, double dec, float equinox) |
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41 | { |
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42 | /** |
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43 | * std::string getIAUNameEQ(double, double, float) |
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44 | * both ra and dec are assumed to be in degrees. |
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45 | * returns name of the form J123456-654321 for equinox = 2000, |
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46 | * and B1234-4321 otherwise |
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47 | */ |
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48 | |
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49 | std::string rastr=decToDMS(ra,"RA",0); |
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50 | rastr.erase(rastr.begin()+2); |
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51 | rastr.erase(rastr.begin()+4); |
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52 | if(equinox==2000.) |
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53 | rastr.erase(rastr.begin()+6,rastr.end()); |
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54 | else |
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55 | rastr.erase(rastr.begin()+4,rastr.end()); |
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56 | std::string decstr=decToDMS(dec,"DEC",0); |
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57 | decstr.erase(decstr.begin()+3); |
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58 | decstr.erase(decstr.begin()+5); |
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59 | if(equinox==2000.) |
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60 | decstr.erase(decstr.begin()+7,decstr.end()); |
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61 | else |
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62 | decstr.erase(decstr.begin()+5,decstr.end()); |
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63 | |
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64 | std::stringstream ss; |
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65 | if(equinox==2000.) ss<<"J"; |
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66 | else ss<<"B"; |
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67 | ss<<rastr<<decstr; |
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68 | return ss.str(); |
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69 | |
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70 | } |
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71 | |
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72 | std::string getIAUNameGAL(double lon, double lat) |
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73 | { |
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74 | /** |
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75 | * std::string getIAUNameGAL(double, double) |
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76 | * both ra and dec are assumed to be in degrees. |
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77 | * returns name of the form G321.123+01.234 |
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78 | */ |
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79 | |
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80 | std::stringstream ss(std::stringstream::out); |
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81 | ss.setf(std::ios::showpoint); |
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82 | ss.setf(std::ios::fixed); |
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83 | ss<<"G"; |
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84 | double goodlon=lon; |
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85 | if(lon<0.) goodlon += 360.; |
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86 | ss<<setw(7)<<setfill('0')<<setprecision(3)<<goodlon; |
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87 | ss.setf(std::ios::showpos); |
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88 | ss.setf(std::ios::internal); |
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89 | ss<<setw(7)<<setfill('0')<<setprecision(3)<<lat; |
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90 | ss.unsetf(std::ios::internal); |
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91 | ss.unsetf(std::ios::showpos); |
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92 | ss.unsetf(std::ios::showpoint); |
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93 | ss.unsetf(std::ios::fixed); |
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94 | return ss.str(); |
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95 | } |
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96 | |
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97 | std::string decToDMS(const double dec, const std::string type, int decPrecision) |
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98 | { |
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99 | /** |
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100 | *Converts a decimal angle (in degrees) to a format reflecting the axis type: |
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101 | * RA (right ascension): hh:mm:ss.ss, with dec modulo 360. (24hrs) |
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102 | * DEC (declination): sdd:mm:ss.ss (with sign, either + or -) |
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103 | * GLON (galactic longitude): ddd:mm:ss.ss, with dec made modulo 360. |
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104 | * GLAT (galactic latitude): sdd:mm:ss.ss (with sign, either + or -) |
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105 | * Any other type defaults to RA, and prints warning. |
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106 | * |
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107 | * \param dec Decimal value of the angle, in degrees. |
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108 | * \param type String indicating desired type of output. Options RA, DEC, |
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109 | * GLON, GLAT |
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110 | * \return String with angle in desired format. |
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111 | */ |
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112 | |
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113 | double dec_abs,degD,minD,minDint,sec; |
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114 | int deg,min; |
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115 | const double minPerHour=60.; |
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116 | const double degPerHour=15.; |
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117 | double thisDec = dec; |
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118 | std::string sign=""; |
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119 | int degSize = 2; // number of figures in the degrees part of the output. |
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120 | |
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121 | int precision=std::max(0,decPrecision); |
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122 | if(type=="RA") precision++; |
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123 | |
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124 | if((type=="RA")||(type=="GLON")){ |
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125 | if(type=="GLON") degSize = 3; // longitude has three figures in degrees. |
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126 | // Make these modulo 360.; |
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127 | while (thisDec < 0.) { thisDec += 360.; } |
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128 | while (thisDec >= 360.) { thisDec -= 360.; } |
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129 | if(type=="RA") thisDec /= degPerHour; // Convert to hours. |
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130 | } |
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131 | else if((type=="DEC")||(type=="GLAT")){ |
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132 | if(thisDec<0.) sign = "-"; |
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133 | else sign = "+"; |
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134 | } |
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135 | else { // UNKNOWN TYPE -- DEFAULT TO RA. |
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136 | std::cerr << "WARNING <decToDMS> : Unknown axis type (" |
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137 | << type << "). Defaulting to using RA.\n"; |
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138 | while (thisDec < 0.) { thisDec += 360.; } |
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139 | while (thisDec >= 360.) { thisDec -= 360.; } |
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140 | thisDec /= degPerHour; |
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141 | } |
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142 | |
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143 | dec_abs = fabs(thisDec); |
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144 | minD = modf(dec_abs, °D) * minPerHour; |
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145 | sec = modf(minD, &minDint) * minPerHour; |
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146 | deg = int(degD); |
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147 | min = int(minDint); |
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148 | |
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149 | if(fabs(sec-minPerHour)<pow(10,-precision)){ // to prevent rounding errors stuffing things up |
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150 | sec=0.; |
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151 | min++; |
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152 | if(min==60){ |
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153 | min=0; |
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154 | deg++; |
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155 | } |
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156 | } |
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157 | |
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158 | std::stringstream ss(std::stringstream::out); |
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159 | ss.setf(std::ios::showpoint); |
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160 | ss.setf(std::ios::fixed); |
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161 | ss << sign; |
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162 | ss << setw(degSize)<<setfill('0')<<deg<<":"; |
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163 | ss<<setw(2)<<setfill('0')<<min<<":"; |
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164 | if(precision>0) |
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165 | ss<<setw(precision+3)<<setprecision(precision)<<sec; |
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166 | else { |
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167 | ss << setw(2) << int(sec); |
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168 | } |
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169 | |
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170 | return ss.str(); |
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171 | } |
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172 | |
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173 | |
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174 | double dmsToDec(std::string dms) |
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175 | { |
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176 | /** |
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177 | * double dmsToDec(string) |
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178 | * Converts a std::string in the format +12:23:34.45 to a decimal angle in degrees. |
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179 | * Assumes the angle given is in degrees, so if passing RA as the argument, |
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180 | * need to multiply by 15 to get the result in degrees rather than hours. |
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181 | * The sign of the angle is preserved, if present. |
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182 | */ |
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183 | |
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184 | |
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185 | bool isNeg = false; |
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186 | if(dms[0]=='-') isNeg = true; |
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187 | |
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188 | std::stringstream ss; |
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189 | ss.str(dms); |
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190 | std::string deg,min,sec; |
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191 | getline(ss,deg,':'); |
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192 | getline(ss,min,':'); |
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193 | getline(ss,sec); |
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194 | char *end; |
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195 | double d = strtod(deg.c_str(),&end); |
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196 | double m = strtod(min.c_str(),&end); |
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197 | double s = strtod(sec.c_str(),&end); |
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198 | |
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199 | double dec = fabs(d) + m/60. + s/3600.; |
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200 | if(isNeg) dec = dec * -1.; |
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201 | |
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202 | return dec; |
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203 | |
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204 | } |
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205 | |
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206 | const long double degToRadian=M_PI/180.; |
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207 | |
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208 | double angularSeparation(double &ra1, double &dec1, double &ra2, double &dec2) |
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209 | { |
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210 | /** |
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211 | * double angularSeparation(double &,double &,double &,double &); |
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212 | * Enter ra & dec for two positions. |
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213 | * (all positions in degrees) |
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214 | * Returns the angular separation in degrees. |
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215 | */ |
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216 | |
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217 | long double dra = (ra1-ra2)*degToRadian; |
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218 | long double d1 = dec1*degToRadian; |
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219 | long double d2 = dec2*degToRadian; |
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220 | long double angsep; |
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221 | if((fabs(ra1-ra2) < 1./3600.)&&(fabs(dec1-dec2)<1./3600.)) |
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222 | return sqrt(dra*dra + (d1-d2)*(d1-d2)) / degToRadian; |
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223 | else { |
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224 | if(fabs(ra1-ra2) < 1./3600.) |
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225 | angsep = cos(d1)*cos(d2) - dra*dra*cos(d1)*cos(d2)/2. + sin(d1)*sin(d2); |
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226 | else |
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227 | angsep = cos(dra)*cos(d1)*cos(d2) + sin(d1)*sin(d2); |
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228 | double dangsep = acos(angsep) / degToRadian; |
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229 | return dangsep; |
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230 | } |
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231 | |
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232 | } |
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