test/java/lang/Math/HypotTests.java

Print this page
rev 11823 : 8078672: Print and allow setting by Java property seeds used to initialize Random instances in java.lang numerics tests
Summary: Add ability to initial the random number generator from the system property "seed" and print to STDOUT the seed value actually used.
Reviewed-by: XXX
   1 /*
   2  * Copyright (c) 2003, 2014, 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  * @bug 4851638 4939441
  27  * @summary Tests for {Math, StrictMath}.hypot



  28  * @author Joseph D. Darcy
  29  * @key randomness
  30  */
  31 
  32 public class HypotTests {
  33     private HypotTests(){}
  34 
  35     static final double infinityD = Double.POSITIVE_INFINITY;
  36     static final double NaNd      = Double.NaN;
  37 
  38     /**
  39      * Given integers m and n, assuming m < n, the triple (n^2 - m^2,
  40      * 2mn, and n^2 + m^2) is a Pythagorean triple with a^2 + b^2 =
  41      * c^2.  This methods returns a long array holding the Pythagorean
  42      * triple corresponding to the inputs.
  43      */
  44     static long [] pythagoreanTriple(int m, int n) {
  45         long M = m;
  46         long N = n;
  47         long result[] = new long[3];


 103             }
 104         }
 105 
 106         // Big ones
 107         for(int m = 100000; m < 100100; m++) {
 108             for(int n = m+100000; n < 200200; n++) {
 109                 long [] result = pythagoreanTriple(m, n);
 110                 failures += testHypotCase(result[0], result[1], result[2]);
 111             }
 112         }
 113 
 114         // Approaching overflow tests
 115 
 116         /*
 117          * Create a random value r with an large-ish exponent.  The
 118          * result of hypot(3*r, 4*r) should be approximately 5*r. (The
 119          * computation of 4*r is exact since it just changes the
 120          * exponent).  While the exponent of r is less than or equal
 121          * to (MAX_EXPONENT - 3), the computation should not overflow.
 122          */
 123         java.util.Random rand = new java.util.Random();
 124         for(int i = 0; i < 1000; i++) {
 125             double d = rand.nextDouble();
 126             // Scale d to have an exponent equal to MAX_EXPONENT -15
 127             d = Math.scalb(d, Double.MAX_EXPONENT
 128                                  -15 - Tests.ilogb(d));
 129             for(int j = 0; j <= 13; j += 1) {
 130                 failures += testHypotCase(3*d, 4*d, 5*d, 2.5);
 131                 d *= 2.0; // increase exponent by 1
 132             }
 133         }
 134 
 135         // Test for monotonicity failures.  Fix one argument and test
 136         // two numbers before and two numbers after each chosen value;
 137         // i.e.
 138         //
 139         // pcNeighbors[] =
 140         // {nextDown(nextDown(pc)),
 141         // nextDown(pc),
 142         // pc,
 143         // nextUp(pc),


   1 /*
   2  * Copyright (c) 2003, 2015, 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  * @library /lib/testlibrary/
  27  * @build jdk.testlibrary.*
  28  * @run main HypotTests
  29  * @bug 4851638 4939441 8078672
  30  * @summary Tests for {Math, StrictMath}.hypot (use -Dseed=X to set PRNG seed)
  31  * @author Joseph D. Darcy
  32  * @key randomness
  33  */
  34 
  35 public class HypotTests {
  36     private HypotTests(){}
  37 
  38     static final double infinityD = Double.POSITIVE_INFINITY;
  39     static final double NaNd      = Double.NaN;
  40 
  41     /**
  42      * Given integers m and n, assuming m < n, the triple (n^2 - m^2,
  43      * 2mn, and n^2 + m^2) is a Pythagorean triple with a^2 + b^2 =
  44      * c^2.  This methods returns a long array holding the Pythagorean
  45      * triple corresponding to the inputs.
  46      */
  47     static long [] pythagoreanTriple(int m, int n) {
  48         long M = m;
  49         long N = n;
  50         long result[] = new long[3];


 106             }
 107         }
 108 
 109         // Big ones
 110         for(int m = 100000; m < 100100; m++) {
 111             for(int n = m+100000; n < 200200; n++) {
 112                 long [] result = pythagoreanTriple(m, n);
 113                 failures += testHypotCase(result[0], result[1], result[2]);
 114             }
 115         }
 116 
 117         // Approaching overflow tests
 118 
 119         /*
 120          * Create a random value r with an large-ish exponent.  The
 121          * result of hypot(3*r, 4*r) should be approximately 5*r. (The
 122          * computation of 4*r is exact since it just changes the
 123          * exponent).  While the exponent of r is less than or equal
 124          * to (MAX_EXPONENT - 3), the computation should not overflow.
 125          */
 126         java.util.Random rand = RandomFactory.getRandom();
 127         for(int i = 0; i < 1000; i++) {
 128             double d = rand.nextDouble();
 129             // Scale d to have an exponent equal to MAX_EXPONENT -15
 130             d = Math.scalb(d, Double.MAX_EXPONENT
 131                                  -15 - Tests.ilogb(d));
 132             for(int j = 0; j <= 13; j += 1) {
 133                 failures += testHypotCase(3*d, 4*d, 5*d, 2.5);
 134                 d *= 2.0; // increase exponent by 1
 135             }
 136         }
 137 
 138         // Test for monotonicity failures.  Fix one argument and test
 139         // two numbers before and two numbers after each chosen value;
 140         // i.e.
 141         //
 142         // pcNeighbors[] =
 143         // {nextDown(nextDown(pc)),
 144         // nextDown(pc),
 145         // pc,
 146         // nextUp(pc),