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: MaxFunction.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 java.math.BigDecimal; 034 035 import org.jfree.formula.EvaluationException; 036 import org.jfree.formula.FormulaContext; 037 import org.jfree.formula.LibFormulaErrorValue; 038 import org.jfree.formula.util.NumberUtil; 039 import org.jfree.formula.function.Function; 040 import org.jfree.formula.function.ParameterCallback; 041 import org.jfree.formula.lvalues.TypeValuePair; 042 import org.jfree.formula.typing.Type; 043 import org.jfree.formula.typing.sequence.NumberSequence; 044 import org.jfree.formula.typing.coretypes.NumberType; 045 046 /** 047 * This function returns the maximum from a set of numbers. 048 * 049 * @author Cedric Pronzato 050 * 051 */ 052 public class MaxFunction implements Function 053 { 054 public static final BigDecimal ZERO = new BigDecimal(0); 055 056 public MaxFunction() 057 { 058 } 059 060 public TypeValuePair evaluate(final FormulaContext context, final ParameterCallback parameters) throws EvaluationException 061 { 062 final int parameterCount = parameters.getParameterCount(); 063 064 if(parameterCount == 0) 065 { 066 return new TypeValuePair(NumberType.GENERIC_NUMBER, ZERO); 067 } 068 069 BigDecimal last = null; 070 for (int paramIdx = 0; paramIdx < parameterCount; paramIdx++) 071 { 072 final Type type = parameters.getType(paramIdx); 073 final Object value = parameters.getValue(paramIdx); 074 final NumberSequence sequence = context.getTypeRegistry().convertToNumberSequence(type, value); 075 076 while(sequence.hasNext()) 077 { 078 final BigDecimal next = NumberUtil.getAsBigDecimal(sequence.nextNumber()); 079 if(last == null) 080 { 081 last = next; 082 } 083 else 084 { 085 if(last.compareTo(next) == -1) 086 { 087 last = next; 088 } 089 } 090 } 091 } 092 if(last == null) 093 { 094 throw new EvaluationException( 095 LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE); 096 } 097 098 return new TypeValuePair(NumberType.GENERIC_NUMBER, last); 099 } 100 101 public String getCanonicalName() 102 { 103 return "MAX"; 104 } 105 106 }