1 /* 2 * Copyright (c) 2011, 2013, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 /* 25 * @test 26 * @summary <rdar://problem/1400112> EXT a2: Math package error is causing this applet to print out the wrong value 27 * @summary com.apple.junit.java.lang.Math 28 */ 29 30 import junit.framework.*; 31 32 public class R1400112FloatPrecisionTest extends TestCase { 33 protected static final double kLog10 = Math.log(10); 34 protected static double ERRMARGIN; 35 protected double origDouble; 36 protected double resultingDouble; 37 38 protected void setUp() { 39 ERRMARGIN = .000000001; 40 origDouble = -1.56; 41 resultingDouble = origDouble; 42 } 43 44 public static Test suite() { 45 return new TestSuite(R1400112FloatPrecisionTest.class); 46 } 47 48 final public static double roundToXSigDigs(double resultingDouble, int sigs) { 49 double absDouble = Math.abs(resultingDouble); 50 double roundFactor = Math.log(absDouble); 51 52 if( absDouble < ERRMARGIN ) { // it's close enough to zero for us 53 return(0); 54 } 55 roundFactor /= kLog10; 56 roundFactor = Math.floor(roundFactor); 57 roundFactor = sigs-1-roundFactor; 58 roundFactor *= kLog10; 59 roundFactor = Math.exp(roundFactor); 60 resultingDouble *= roundFactor; 61 resultingDouble = Math.round(resultingDouble); 62 resultingDouble /= roundFactor; 63 return (resultingDouble); 64 } 65 66 public void testR1400112FloatPrecision() { 67 resultingDouble = roundToXSigDigs(resultingDouble, 4); 68 assertTrue ("Math on doubles is functional", Math.abs(resultingDouble - origDouble) < ERRMARGIN ); 69 } 70 71 public static void main (String[] args) throws RuntimeException { 72 TestResult tr = junit.textui.TestRunner.run(suite()); 73 if ((tr.errorCount() != 0) || (tr.failureCount() != 0)) { 74 throw new RuntimeException("### FAILED: unexpected JUnit errors or failures."); 75 } 76 } 77 } 78