SloanCoords.hxx

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//-----------------------------------------------------------------------------
// CVS: $Revision: 4695 $, $Date: 2008-04-09 16:18:42 +0100 (Wed, 09 Apr 2008) $, $Author: EckhardSutorius $
//-----------------------------------------------------------------------------
#ifndef SLOANCOORDS_H
#define SLOANCOORDS_H

#include <cmath>

#include "Constants.h"
#include "Converter.h"
#include "DataMethod.hxx"
#include "StringOps.h"
//-----------------------------------------------------------------------------
template<typename DataType>
class SloanCoords : public DataMethod<DataType>
{
public:
  SloanCoords() { DataMethod<DataType>::methodName = "SloanCoords"; }

  virtual ~SloanCoords() { }

  //---------------------------------------------------------------------------
  void setSource(IntMap& tbls, IntMap& cols, StringMap units)
  {
    raColno  = cols[0];
    decColno = cols[1];

    // Require radians for the calculation
    decFact = converter.getFactor(units[0], "RADIANS");
    raFact  = converter.getFactor(units[1], "RADIANS");

    // Constants for the co-ordinate transformation
    degToRad = converter.getFactor("degrees", "radians");
    raOffset = -95.0*degToRad;
    etaOffset = +32.5*degToRad;
  }
  //---------------------------------------------------------------------------
  void setTarget(IntMap& cols, StringMap units)
  {
    lambdaColno = cols[0];
    etaColno = cols[1];

    // Check required output units for lambda and eta
    lFact = converter.getFactor("RADIANS", units[0]);
    eFact = converter.getFactor("RADIANS", units[1]);
  }
  //---------------------------------------------------------------------------
  void doit(TableData<DataType>& data, int row1, int row2)
  {
    for (int rowNo = row1; rowNo < row2; ++rowNo)
    {
      // Input RA and DEC
      double ra, dec;
      data.value(raColno, rowNo, ra);
      data.value(decColno, rowNo, dec);

      // Convert RA and DEC to radians
      ra  *= raFact;
      dec *= decFact;

      double x = cos(ra + raOffset)*cos(dec);
      double y = sin(ra + raOffset)*cos(dec);
      double z = sin(dec);

      Numeric lambda = -1.0 * asin(x) * lFact;
      Numeric eta = (atan2(z,y) - etaOffset) * eFact;

      if (eta < -180.0) eta += 360.0;
      if (eta > 180.0) eta -= 360.0;

      // Assign to correct columns
      data.assign(lambdaColno, rowNo, lambda);
      data.assign(etaColno, rowNo, eta);
    }
  }

  // No data from raw data included
  void doit2(TableData<DataType>& rawData, TableData<DataType>& data, int row1, int row2) { }
  //---------------------------------------------------------------------------
private:
  int lambdaColno, etaColno, raColno, decColno;
  double decFact, raFact, lFact, eFact;
  double degToRad, raOffset, etaOffset;
  Converter converter;
};
//-----------------------------------------------------------------------------
#endif
//-----------------------------------------------------------------------------
// Change log:
//
// 27-May-2004,  IAB: Original version; "Not complete as I can't find
//                    the formula."
//  4-Aug-2004,  NCH: Added in co-ordinate transformations from
//                    Stoughton et al., Astronomical Journal, 123, 485 (2002)
// 28-Oct-2005, ETWS: Changed to SDSSPix code to take care of the
//                    singularity at the pole.
// 22-Mar-2007,  RSC: Robustified against dodgy WCS values.
//  2-May-2007,  RSC: Reverted to original design of allowing dodgy WCS values.
//  7-Apr-2008, ETWS: Upgraded to use new detection table layout.

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