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: ModFunction.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 import org.jfree.formula.util.NumberUtil;
042
043 import java.math.BigDecimal;
044
045 /**
046 * This function returns the remainder when one number is divided by another number.
047 *
048 * @author Cedric Pronzato
049 */
050 public class ModFunction implements Function
051 {
052 public ModFunction()
053 {
054 }
055
056 public TypeValuePair evaluate(final FormulaContext context, final ParameterCallback parameters) throws EvaluationException
057 {
058 final int parameterCount = parameters.getParameterCount();
059 if (parameterCount != 2)
060 {
061 throw new EvaluationException(LibFormulaErrorValue.ERROR_ARGUMENTS_VALUE);
062 }
063 final Type type1 = parameters.getType(0);
064 final Object value1 = parameters.getValue(0);
065 final BigDecimal divided = NumberUtil.getAsBigDecimal(context.getTypeRegistry().convertToNumber(type1, value1));
066 final Type type2 = parameters.getType(1);
067 final Object value2 = parameters.getValue(1);
068 final BigDecimal divisor = NumberUtil.getAsBigDecimal(context.getTypeRegistry().convertToNumber(type2, value2));
069 if(divisor.signum() == 0)
070 {
071 throw new EvaluationException(LibFormulaErrorValue.ERROR_ARITHMETIC_VALUE);
072 }
073
074 final BigDecimal divide = new BigDecimal(divided.divide(divisor, 0, BigDecimal.ROUND_FLOOR).intValue());
075 BigDecimal reminder = divided.subtract(divisor.multiply(divide));
076 if(divide.signum() == 0)
077 {
078 if((divided.signum() == -1 && divisor.signum() != -1) || (divisor.signum() == -1 && divided.signum() != -1))
079 {
080 reminder = divided.add(divisor);
081 }
082 }
083
084 return new TypeValuePair(NumberType.GENERIC_NUMBER, reminder);
085 }
086
087 public String getCanonicalName()
088 {
089 return "MOD";
090 }
091
092 }