numberformatter.java

一个数据挖掘软件ALPHAMINERR的整个过程的JAVA版源代码

/*
 *    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 2 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, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*
 * Created on 2005/3/30
 *
 * $Author$
 * $Date$
 * $Revision$
 *
 */
package eti.bi.util;


import java.text.DecimalFormat;

import eti.bi.common.data.MissingValue;

/**
 * @author kelvinj
 *
 * TODO To change the template for this generated type comment go to
 * Window - Preferences - Java - Code Style - Code Templates
 */
public class NumberFormatter {

	public final static int MAX_FRACTION_DIGIT = 3;
	public final static boolean ALWAYS_SHOWN_SEPARATOR = false;
	public final static double FORMAT_THRESHOLD = 0.001;
	
	private static DecimalFormat m_DecimalFormat = new DecimalFormat();
	private static DecimalFormat m_ScientificFormat = new DecimalFormat();
	private static String m_scientificPattern = "0.###E00";
	
	static
	{
		m_DecimalFormat.setDecimalSeparatorAlwaysShown(ALWAYS_SHOWN_SEPARATOR); 
		m_DecimalFormat.setMaximumFractionDigits(MAX_FRACTION_DIGIT);
		m_DecimalFormat.setGroupingUsed(false);
		
		m_ScientificFormat.setDecimalSeparatorAlwaysShown(ALWAYS_SHOWN_SEPARATOR); 
		m_ScientificFormat.setMaximumFractionDigits(MAX_FRACTION_DIGIT);
		m_ScientificFormat.applyPattern(m_scientificPattern);
	}
	/**
	 * Constructor 
	 */
	public NumberFormatter() {
		super();
		
	}
	
	public static String format(double a_Double)
	{
		if (Double.isNaN(a_Double))
		{
			return MissingValue.DISPLAY_VALUE;
		}else if (a_Double<FORMAT_THRESHOLD && a_Double>0)
		{
			//	If value is in between FORMAT_THRESHOLD and zero, use scientific representation
			return m_ScientificFormat.format(a_Double);
		}else
		{
			return m_DecimalFormat.format(a_Double);
		}
	}
	
	public static String decimalFormat(double a_Double, int a_MaximumFractionDigits)
	{
		if (Double.isNaN(a_Double))
		{
			return MissingValue.DISPLAY_VALUE;
		}
		
		DecimalFormat aDecimalFormat = new DecimalFormat();
		aDecimalFormat.setDecimalSeparatorAlwaysShown(false); 
		aDecimalFormat.setMaximumFractionDigits(a_MaximumFractionDigits);
		aDecimalFormat.setGroupingUsed(false);
		
		return aDecimalFormat.format(a_Double);
	}

	public static String format(int a_Int)
	{
		return String.valueOf(a_Int);
	}
}