Source for org.jfree.formula.util.NumberUtil

   1: /**
   2:  * =========================================
   3:  * LibFormula : a free Java formula library
   4:  * =========================================
   5:  *
   6:  * Project Info:  http://reporting.pentaho.org/libformula/
   7:  *
   8:  * (C) Copyright 2006-2007, by Pentaho Corporation and Contributors.
   9:  *
  10:  * This library is free software; you can redistribute it and/or modify it under the terms
  11:  * of the GNU Lesser General Public License as published by the Free Software Foundation;
  12:  * either version 2.1 of the License, or (at your option) any later version.
  13:  *
  14:  * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
  15:  * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  16:  * See the GNU Lesser General Public License for more details.
  17:  *
  18:  * You should have received a copy of the GNU Lesser General Public License along with this
  19:  * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  20:  * Boston, MA 02111-1307, USA.
  21:  *
  22:  * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
  23:  * in the United States and other countries.]
  24:  *
  25:  *
  26:  * ------------
  27:  * $Id: NumberUtil.java 3522 2007-10-16 10:56:57Z tmorgner $
  28:  * ------------
  29:  * (C) Copyright 2006-2007, by Pentaho Corporation.
  30:  */
  31: 
  32: package org.jfree.formula.util;
  33: 
  34: import java.math.BigDecimal;
  35: 
  36: import org.jfree.formula.EvaluationException;
  37: import org.jfree.formula.LibFormulaErrorValue;
  38: 
  39: public class NumberUtil
  40: {
  41:   public static final BigDecimal DELTA = new BigDecimal("0.000000000000000000000000000005");
  42: 
  43:   private NumberUtil()
  44:   {
  45:   }
  46: 
  47:   public static BigDecimal getAsBigDecimal(final Number number) throws EvaluationException
  48:   {
  49:     if (number == null)
  50:     {
  51:       throw new EvaluationException(
  52:           LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE);
  53:     }
  54:     
  55:     if(number instanceof BigDecimal)
  56:     {
  57:       return (BigDecimal)number;
  58:     }
  59:     else
  60:     {
  61:       return new BigDecimal(number.toString());
  62:     }
  63:   }
  64:   
  65:   public static Integer performIntRounding(BigDecimal n)
  66:   {
  67: 
  68:     try
  69:     {
  70:       // no need to go further if the value is already an integer
  71:       n = n.setScale(0);
  72:       return new Integer(n.intValue());
  73:     }
  74:     catch(ArithmeticException e)
  75:     {
  76:       //ignore and continue
  77:     }
  78:     
  79:     final BigDecimal round;
  80:     if(n.signum()<0)
  81:     {
  82:       n = n.subtract(DELTA);
  83:       round = n.setScale(0, BigDecimal.ROUND_UP);
  84:     }
  85:     else
  86:     {
  87:       n = n.add(DELTA);
  88:       round = n.setScale(1, BigDecimal.ROUND_DOWN);
  89:     }
  90:     return new Integer(round.intValue());
  91:   }
  92:   
  93:   public static BigDecimal removeTrailingZeros(BigDecimal bd)
  94:   {
  95:     if(bd.signum() == 0)
  96:     {
  97:       return bd.setScale(0);
  98:     }
  99: 
 100:     // Todo: This approach is very expensive. There must be a better way ...
 101:     try
 102:     {
 103:       while(true)
 104:       {
 105:         final int scale = bd.scale();
 106:         if (scale == 0)
 107:         {
 108:           return bd;
 109:         }
 110:         bd = bd.setScale(scale-1);
 111:       }
 112:     }
 113:     catch(ArithmeticException ae)
 114:     {
 115:       return bd;
 116:     }
 117:   }
 118: }