angsep.cpp

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/***************************************************************************
 *  angsep.cpp: CppEphem                                                   *
 * ----------------------------------------------------------------------- *
 *  Copyright © 2017-2019 JCardenzana                                      *
 * ----------------------------------------------------------------------- *
 *                                                                         *
 *  This program is free software: you can redistribute it and/or modify   *
 *  it under the terms of the GNU General Public License as published by   *
 *  the Free Software Foundation, either version 3 of the License, or      *
 *  (at your option) any later version.                                    *
 *                                                                         *
 *  This program is distributed in the hope that it will be useful,        *
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of         *
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the          *
 *  GNU General Public License for more details.                           *
 *                                                                         *
 *  You should have received a copy of the GNU General Public License      *
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.  *
 *                                                                         *
 ***************************************************************************/
 
#include <stdio.h>
 
#include "CEExecOptions.h"
#include "CESkyCoord.h"
 
/*********************************************
 * Forward declarations
 *********************************************/
 
CEExecOptions DefineOpts() ;
CESkyCoord ConstructCoords(const double& x, const double& y, bool isDeg);
 
/*********************************************
 * MAIN
 *********************************************/
int main(int argc, char** argv)
{
    // Create and parse the command line options
    CEExecOptions opts = DefineOpts();
    if (opts.ParseCommandLine(argc,argv)) return 0;
    
    // Establish the input coordinate type
    CEAngleType in_ang_type  = CEAngleType::DEGREES;
    
    if (!opts.AsBool("InputDegrees")) {
        in_ang_type = CEAngleType::RADIANS;
    }
    
    // Find coordinates for the first object
    CESkyCoord coord1 = ConstructCoords(opts.AsDouble("xcoord1"),
                                        opts.AsDouble("ycoord1"),
                                        opts.AsBool("InputDegrees"));
    CESkyCoord coord2 = ConstructCoords(opts.AsDouble("xcoord2"),
                                        opts.AsDouble("ycoord2"),
                                        opts.AsBool("InputDegrees"));
 
    CEAngle angsep = CESkyCoord::AngularSeparation(coord1, coord2);
    
    // Figure out whether we need to convert the output angular separation
    if (opts.AsBool("OutputDegrees")) {
        std::cout << angsep.Deg() << std::endl;
    } else {
        std::cout << angsep.Rad() << std::endl;
    }
    
    return 0;
}
 
/*********************************************
 * Define the options available from the command line
 *********************************************/
CEExecOptions DefineOpts()
{
    CEExecOptions opts("angsep");
 
    // Add program description
    opts.AddProgramDescription(std::string() +
        "Computes the angular separation between two coordinates. Note that " +
        "the coordinate types need to be the same for both positions.");
    
    // Specify the actual options
    opts.AddBoolParam("InputDegrees",
                      "Specifies whether input angles are in degrees (1) or radians (0)",
                      true);
    opts.AddBoolParam("OutputDegrees",
                      "Specifies whether to output the angular separation in degrees (1) or radians (0)",
                      true);
    opts.AddDoubleParam("xcoord1",
                        "X-coordinate for first position. Should be either 'right ascension' or 'galactic longitude'",
                        0.0);
    opts.AddDoubleParam("ycoord1",
                        "Y-coordinate for first position. Should be either 'declination' or 'galactic latitude'",
                        0.0);
    opts.AddDoubleParam("xcoord2",
                        "X-coordinate for second position. Should be either 'right ascension' or 'galactic longitude'",
                        0.0);
    opts.AddDoubleParam("ycoord2",
                        "Y-coordinate for second position. Should be either 'declination' or 'galactic latitude'",
                        0.0);
    
    return opts;
}
 
 
/*****************************************/
CESkyCoord ConstructCoords(const double& x, const double& y, bool isDeg)
{
    CESkyCoord coord;
    if (isDeg) {
        coord.SetCoordinates(CEAngle::Deg(x), CEAngle::Deg(y),
                             CESkyCoordType::ICRS);
    } else {
        coord.SetCoordinates(CEAngle::Rad(x), CEAngle::Rad(y),
                             CESkyCoordType::ICRS);
    }
 
    return coord;
}