code: /*******************************************************************************
   * Copyright (c) 2018 Attila Kovacs <attila[AT]sigmyne.com>.
   * All rights reserved. 
   * 
   * This file is part of crush.
   * 
   *     crush 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.
   * 
   *     crush 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 crush.  If not, see <http://www.gnu.org/licenses/>.
   * 
   * Contributors:
   *     Attila Kovacs <attila[AT]sigmyne.com> - initial API and implementation
   ******************************************************************************/
  
  package crush.telescope.sofia;
  
  import jnum.Unit;
  import jnum.fits.FitsToolkit;
  import jnum.math.Vector2D;
  import nom.tam.fits.Header;
  import nom.tam.fits.HeaderCard;
  import nom.tam.fits.HeaderCardException;
  import nom.tam.util.Cursor;
  
  public class SofiaDitheringData extends SofiaData {
      public String coordinateSystem;
      public Vector2D offset = new Vector2D(Double.NaN, Double.NaN);
      public String patternShape;
      public int positions = UNKNOWN_INT_VALUE;
      public int index = UNKNOWN_INT_VALUE;
  
      public SofiaDitheringData() {}
  
      public SofiaDitheringData(SofiaHeader header) {
          this();
          parseHeader(header);
      }
  
      public void parseHeader(SofiaHeader header) {
          coordinateSystem = header.getString("DTHCRSYS");		// new in 3.0
  
          offset = new Vector2D(Double.NaN, Double.NaN);
          offset.setX(header.getDouble("DTHXOFF"));
          offset.setY(header.getDouble("DTHYOFF"));
       
          patternShape = header.getString("DTHPATT");
          positions = header.getInt("DTHNPOS");
          index = header.getInt("DTHINDEX");
      }
  
      @Override
      public void editHeader(Header header) throws HeaderCardException {
          Cursor<String, HeaderCard> c = FitsToolkit.endOf(header);
          c.add(new HeaderCard("COMMENT", "<------ SOFIA Dithering Data ------>", false));
          
          c.add(makeCard("DTHCRSYS", coordinateSystem, "Dither coordinate system."));
          
          Vector2D v = offset == null ? new Vector2D(Double.NaN, Double.NaN) : offset;
          c.add(makeCard("DTHXOFF", v.x() / Unit.arcsec, "(arcsec) Dither X offset."));
          c.add(makeCard("DTHYOFF", v.y() / Unit.arcsec, "(arcsec) Dither Y offset."));
          
          c.add(makeCard("DTHPATT", patternShape, "Approximate shape of dither pattern."));
          c.add(makeCard("DTHNPOS", positions, "Number of dither positions."));
          c.add(makeCard("DTHINDEX", index, "Dither position index."));
      }
  
      @Override
      public String getLogID() {
          return "dither";
      }
  
      @Override
      public Object getTableEntry(String name) {
          if(name.equals("dx")) return offset.x() / Unit.arcsec;
          else if(name.equals("dy")) return offset.y() / Unit.arcsec;
          else if(name.equals("index")) return index;
          else if(name.equals("pattern")) return patternShape;
          else if(name.equals("npos")) return positions;
          else if(name.equals("sys")) return coordinateSystem;
         
          return super.getTableEntry(name);
      }
      
      
  }
  