001    /**
002     * =========================================
003     * LibFormula : a free Java formula library
004     * =========================================
005     *
006     * Project Info:  http://reporting.pentaho.org/libformula/
007     *
008     * (C) Copyright 2006-2007, by Pentaho Corporation and Contributors.
009     *
010     * This library is free software; you can redistribute it and/or modify it under the terms
011     * of the GNU Lesser General Public License as published by the Free Software Foundation;
012     * either version 2.1 of the License, or (at your option) any later version.
013     *
014     * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
015     * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
016     * See the GNU Lesser General Public License for more details.
017     *
018     * You should have received a copy of the GNU Lesser General Public License along with this
019     * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
020     * Boston, MA 02111-1307, USA.
021     *
022     * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
023     * in the United States and other countries.]
024     *
025     *
026     * ------------
027     * $Id: OddFunction.java 3521 2007-10-16 10:55:14Z tmorgner $
028     * ------------
029     * (C) Copyright 2006-2007, by Pentaho Corporation.
030     */
031    package org.jfree.formula.function.math;
032    
033    import org.jfree.formula.EvaluationException;
034    import org.jfree.formula.FormulaContext;
035    import org.jfree.formula.LibFormulaErrorValue;
036    import org.jfree.formula.function.Function;
037    import org.jfree.formula.function.ParameterCallback;
038    import org.jfree.formula.lvalues.TypeValuePair;
039    import org.jfree.formula.typing.Type;
040    import org.jfree.formula.typing.coretypes.NumberType;
041    
042    /**
043     * This function returns the rounding a number up to the nearest odd integer,
044     * where "up" means "away from 0".
045     * 
046     * @author Cedric Pronzato
047     * 
048     */
049    public class OddFunction implements Function
050    {
051    
052      public OddFunction()
053      {
054      }
055    
056      public TypeValuePair evaluate(final FormulaContext context,
057          final ParameterCallback parameters) throws EvaluationException
058      {
059        final int parameterCount = parameters.getParameterCount();
060        if (parameterCount < 1)
061        {
062          throw new EvaluationException(LibFormulaErrorValue.ERROR_ARGUMENTS_VALUE);
063        }
064        final Type type1 = parameters.getType(0);
065        final Object value1 = parameters.getValue(0);
066        final Number result = context.getTypeRegistry().convertToNumber(type1,
067            value1);
068    
069        final int intValue = result.intValue();
070        Integer ret;
071    
072        int test = intValue;
073        if (intValue < 0)
074        {
075          test = intValue * -1;
076        }
077    
078        if (test % 2 == 1)
079        {
080          ret = new Integer(intValue);
081        }
082        else
083        {
084          if (result.doubleValue() < 0)
085          {
086            ret = new Integer(intValue - 1);
087          }
088          else
089          {
090            ret = new Integer(intValue + 1);
091          }
092        }
093    
094        return new TypeValuePair(NumberType.GENERIC_NUMBER, ret);
095      }
096    
097      public String getCanonicalName()
098      {
099        return "ODD";
100      }
101    
102    }