Source for org.jfree.formula.function.math.ModFunction

   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: ModFunction.java 3521 2007-10-16 10:55:14Z tmorgner $
  28:  * ------------
  29:  * (C) Copyright 2006-2007, by Pentaho Corporation.
  30:  */
  31: package org.jfree.formula.function.math;
  32: 
  33: import org.jfree.formula.EvaluationException;
  34: import org.jfree.formula.FormulaContext;
  35: import org.jfree.formula.LibFormulaErrorValue;
  36: import org.jfree.formula.function.Function;
  37: import org.jfree.formula.function.ParameterCallback;
  38: import org.jfree.formula.lvalues.TypeValuePair;
  39: import org.jfree.formula.typing.Type;
  40: import org.jfree.formula.typing.coretypes.NumberType;
  41: import org.jfree.formula.util.NumberUtil;
  42: 
  43: import java.math.BigDecimal;
  44: 
  45: /**
  46:  * This function returns the remainder when one number is divided by another number.
  47:  *
  48:  * @author Cedric Pronzato
  49:  */
  50: public class ModFunction implements Function
  51: {
  52:   public ModFunction()
  53:   {
  54:   }
  55: 
  56:   public TypeValuePair evaluate(final FormulaContext context, final ParameterCallback parameters) throws EvaluationException
  57:   {
  58:     final int parameterCount = parameters.getParameterCount();
  59:     if (parameterCount != 2)
  60:     {
  61:       throw new EvaluationException(LibFormulaErrorValue.ERROR_ARGUMENTS_VALUE);
  62:     }
  63:     final Type type1 = parameters.getType(0);
  64:     final Object value1 = parameters.getValue(0);
  65:     final BigDecimal divided = NumberUtil.getAsBigDecimal(context.getTypeRegistry().convertToNumber(type1, value1));
  66:     final Type type2 = parameters.getType(1);
  67:     final Object value2 = parameters.getValue(1);
  68:     final BigDecimal divisor = NumberUtil.getAsBigDecimal(context.getTypeRegistry().convertToNumber(type2, value2));
  69:     if(divisor.signum() == 0)
  70:     {
  71:       throw new EvaluationException(LibFormulaErrorValue.ERROR_ARITHMETIC_VALUE);
  72:     }
  73: 
  74:     final BigDecimal divide = new BigDecimal(divided.divide(divisor, 0, BigDecimal.ROUND_FLOOR).intValue());
  75:     BigDecimal reminder = divided.subtract(divisor.multiply(divide));
  76:     if(divide.signum() == 0)
  77:     {
  78:       if((divided.signum() == -1 && divisor.signum() != -1) || (divisor.signum() == -1 && divided.signum() != -1))
  79:       {
  80:         reminder = divided.add(divisor);
  81:       }
  82:     }
  83: 
  84:     return new TypeValuePair(NumberType.GENERIC_NUMBER, reminder);
  85:   }
  86: 
  87:   public String getCanonicalName()
  88:   {
  89:     return "MOD";
  90:   }
  91: