code: /*******************************************************************************
   * Copyright (c) 2013 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.iram;
  
  import java.io.*;
  import java.text.*;
  import java.util.*;
  
  import crush.CRUSH;
  import jnum.Unit;
  import jnum.Util;
  import jnum.astro.AstroTime;
  import jnum.data.DataPoint;
  import jnum.data.ScalarLocality;
  import jnum.io.LineParser;
  import jnum.text.SmartTokenizer;
  import jnum.data.LocalAverage;
  import jnum.data.Locality;
  import jnum.data.LocalizedData;
  
  public class IRAMTauTable extends LocalAverage<IRAMTauTable.Entry> {
  	
  	/**
  	 * 
  	 */
  	private static final long serialVersionUID = 3850376076747456359L;
  
  	public String fileName = "";
  
  	public double timeWindow = 15.0 * Unit.min;
  	
  	private static Hashtable<String, IRAMTauTable> tables = new Hashtable<>();
  
  	public static IRAMTauTable get(String fileName, String timeZone) throws IOException {
  		IRAMTauTable table = tables.get(fileName);
  		if(table == null) {
  			table = new IRAMTauTable(fileName, timeZone);
  			tables.put(fileName, table);
  		}
  		return table;
  	}
  	
  		
  	private IRAMTauTable(String fileName, String timeZone) throws IOException {
  		read(fileName, timeZone);
  	}
  	
  	private void read(String fileName, String timeZone) throws IOException {
  		if(fileName.equals(this.fileName)) return;
  			
  
  		final SimpleDateFormat df = new SimpleDateFormat("hh:mm:ss yyyy-MM-dd");
          df.setTimeZone(TimeZone.getTimeZone(timeZone));	
  		
          new LineParser() {
  
              @Override
              protected boolean parse(String line) throws Exception {
                  SmartTokenizer tokens = new SmartTokenizer(line);     
                  if(tokens.countTokens() < 4) return false;
                  
                  Entry skydip = new Entry();
                  String dateSpec = tokens.nextToken() + " " + tokens.nextToken();
                  Date date = df.parse(dateSpec);
                  skydip.timeStamp = new TimeStamp(AstroTime.getMJD(date.getTime()));         
                  
                  skydip.tau.setValue(tokens.nextDouble());    
                  skydip.tau.setRMS(tokens.nextDouble());
                  add(skydip);
                  return true;
              }
          }.read(fileName);
  			
          CRUSH.info(this, "[Loading skydip tau values.] -- " + size() + " valid records found.");
          if(CRUSH.debug) CRUSH.detail(this, " >> " + fileName + " >> ");
  		
  		this.fileName = fileName;
  		
  		Collections.sort(this);
  		
  	}
  	
  	public double getTau(double MJD) {
  		Entry mean = getCheckedLocalAverage(new TimeStamp(MJD));
  		CRUSH.values(this, "Local average tau(225GHz) = " + mean.tau.toString(Util.f3) + " (from " + mean.measurements + " measurements)");
  		return mean.tau.value();
  	}
  	
  	
  	class TimeStamp extends ScalarLocality {
  		
  		public TimeStamp(double MJD) { super(MJD); }
  		
  		@Override
  		public double distanceTo(Locality other) {
  			return super.distanceTo(other) * Unit.day / Math.abs(timeWindow);
  		}
  	}
  
  	class Entry extends LocalizedData {
  		/**
  		 * 
  		 */
  		private static final long serialVersionUID = -7635791450826001376L;
  		TimeStamp timeStamp;
  		DataPoint tau = new DataPoint();
  		
  		@Override
  		public Locality getLocality() {
  			return timeStamp;
  		}
  
  		@Override
  		public void setLocality(Locality loc) {
  			timeStamp = (TimeStamp) loc;
  		}
  
  		@Override
  		protected void averageWidth(LocalizedData other, Object env, double relativeWeight) {	
  			Entry point = (Entry) other;	
  			tau.average(point.tau.value(), relativeWeight * point.tau.weight());
  		}
  
  		@Override
  		public boolean isConsistentWith(LocalizedData other) {
  			Entry entry = (Entry) other;
  			DataPoint difference = entry.tau.copy();
  			difference.subtract(tau);	
  			return Math.abs(difference.significance()) < 5.0;
  		}
  		
  		@Override
  		public String toString() { 
  			return timeStamp.toString() + ": " + tau;
  		}
  		
  	}
  
  	@Override
  	public Entry getLocalizedDataInstance() {
  		return new Entry();
  	}
  
  	
  }
  
  
  