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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: PowerOperator.java 2752 2007-04-10 14:10:41Z taqua $ 28: * ------------ 29: * (C) Copyright 2006-2007, by Pentaho Corporation. 30: */ 31: package org.jfree.formula.operators; 32: 33: import org.jfree.formula.EvaluationException; 34: 35: /** 36: * This has to be implemented manually if we want to support arbitary precision. 37: * Damn, do I have to implement the logarithm computation as well? For now: 38: * Ignore that and use doubles! 39: * 40: * @author Thomas Morgner 41: */ 42: public class PowerOperator extends AbstractNumericOperator 43: { 44: public PowerOperator() 45: { 46: } 47: 48: protected Number evaluate(final Number number1, final Number number2) throws EvaluationException 49: { 50: final double result = Math.pow(number1.doubleValue(), number2.doubleValue()); 51: return new Double(result); 52: } 53: 54: public int getLevel() 55: { 56: return 0; 57: } 58: 59: public String toString() 60: { 61: return "POW"; 62: } 63: 64: public boolean isLeftOperation() 65: { 66: return false; 67: } 68: 69: /** 70: * Defines, whether the operation is associative. For associative operations, 71: * the evaluation order does not matter, if the operation appears more than 72: * once in an expression, and therefore we can optimize them a lot better than 73: * non-associative operations (ie. merge constant parts and precompute them 74: * once). 75: * 76: * @return true, if the operation is associative, false otherwise 77: */ 78: public boolean isAssociative() 79: { 80: return false; 81: } 82: 83: }