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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: MaxFunction.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 java.math.BigDecimal; 34: 35: import org.jfree.formula.EvaluationException; 36: import org.jfree.formula.FormulaContext; 37: import org.jfree.formula.LibFormulaErrorValue; 38: import org.jfree.formula.util.NumberUtil; 39: import org.jfree.formula.function.Function; 40: import org.jfree.formula.function.ParameterCallback; 41: import org.jfree.formula.lvalues.TypeValuePair; 42: import org.jfree.formula.typing.Type; 43: import org.jfree.formula.typing.sequence.NumberSequence; 44: import org.jfree.formula.typing.coretypes.NumberType; 45: 46: /** 47: * This function returns the maximum from a set of numbers. 48: * 49: * @author Cedric Pronzato 50: * 51: */ 52: public class MaxFunction implements Function 53: { 54: public static final BigDecimal ZERO = new BigDecimal(0); 55: 56: public MaxFunction() 57: { 58: } 59: 60: public TypeValuePair evaluate(final FormulaContext context, final ParameterCallback parameters) throws EvaluationException 61: { 62: final int parameterCount = parameters.getParameterCount(); 63: 64: if(parameterCount == 0) 65: { 66: return new TypeValuePair(NumberType.GENERIC_NUMBER, ZERO); 67: } 68: 69: BigDecimal last = null; 70: for (int paramIdx = 0; paramIdx < parameterCount; paramIdx++) 71: { 72: final Type type = parameters.getType(paramIdx); 73: final Object value = parameters.getValue(paramIdx); 74: final NumberSequence sequence = context.getTypeRegistry().convertToNumberSequence(type, value); 75: 76: while(sequence.hasNext()) 77: { 78: final BigDecimal next = NumberUtil.getAsBigDecimal(sequence.nextNumber()); 79: if(last == null) 80: { 81: last = next; 82: } 83: else 84: { 85: if(last.compareTo(next) == -1) 86: { 87: last = next; 88: } 89: } 90: } 91: } 92: if(last == null) 93: { 94: throw new EvaluationException( 95: LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE); 96: } 97: 98: return new TypeValuePair(NumberType.GENERIC_NUMBER, last); 99: } 100: 101: public String getCanonicalName() 102: { 103: return "MAX"; 104: } 105: