test/java/lang/Math/HypotTests.java

Print this page




   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  */
  30 
  31 import sun.misc.DoubleConsts;
  32 
  33 public class HypotTests {
  34     private HypotTests(){}
  35 
  36     static final double infinityD = Double.POSITIVE_INFINITY;
  37     static final double NaNd      = Double.NaN;
  38 
  39     /**
  40      * Given integers m and n, assuming m < n, the triple (n^2 - m^2,
  41      * 2mn, and n^2 + m^2) is a Pythagorean triple with a^2 + b^2 =
  42      * c^2.  This methods returns a long array holding the Pythagorean
  43      * triple corresponding to the inputs.
  44      */
  45     static long [] pythagoreanTriple(int m, int n) {
  46         long M = m;
  47         long N = n;
  48         long result[] = new long[3];
  49 
  50 
  51         result[0] = Math.abs(M*M - N*N);


  69             {1.0,               NaNd,                   NaNd},
  70             {Double.longBitsToDouble(0x7FF0000000000001L),      1.0,    NaNd},
  71             {Double.longBitsToDouble(0xFFF0000000000001L),      1.0,    NaNd},
  72             {Double.longBitsToDouble(0x7FF8555555555555L),      1.0,    NaNd},
  73             {Double.longBitsToDouble(0xFFF8555555555555L),      1.0,    NaNd},
  74             {Double.longBitsToDouble(0x7FFFFFFFFFFFFFFFL),      1.0,    NaNd},
  75             {Double.longBitsToDouble(0xFFFFFFFFFFFFFFFFL),      1.0,    NaNd},
  76             {Double.longBitsToDouble(0x7FFDeadBeef00000L),      1.0,    NaNd},
  77             {Double.longBitsToDouble(0xFFFDeadBeef00000L),      1.0,    NaNd},
  78             {Double.longBitsToDouble(0x7FFCafeBabe00000L),      1.0,    NaNd},
  79             {Double.longBitsToDouble(0xFFFCafeBabe00000L),      1.0,    NaNd},
  80         };
  81 
  82         for(int i = 0; i < testCases.length; i++) {
  83             failures += testHypotCase(testCases[i][0], testCases[i][1],
  84                                       testCases[i][2]);
  85         }
  86 
  87         // Verify hypot(x, 0.0) is close to x over the entire exponent
  88         // range.
  89         for(int i = DoubleConsts.MIN_SUB_EXPONENT;
  90             i <= DoubleConsts.MAX_EXPONENT;
  91             i++) {
  92             double input = Math.scalb(2, i);
  93             failures += testHypotCase(input, 0.0, input);
  94         }
  95 
  96 
  97         // Test Pythagorean triples
  98 
  99         // Small ones
 100         for(int m = 1; m < 10; m++) {
 101             for(int n = m+1; n < 11; n++) {
 102                 long [] result = pythagoreanTriple(m, n);
 103                 failures += testHypotCase(result[0], result[1], result[2]);
 104             }
 105         }
 106 
 107         // Big ones
 108         for(int m = 100000; m < 100100; m++) {
 109             for(int n = m+100000; n < 200200; n++) {
 110                 long [] result = pythagoreanTriple(m, n);
 111                 failures += testHypotCase(result[0], result[1], result[2]);
 112             }
 113         }
 114 
 115         // Approaching overflow tests
 116 
 117         /*
 118          * Create a random value r with an large-ish exponent.  The
 119          * result of hypot(3*r, 4*r) should be approximately 5*r. (The
 120          * computation of 4*r is exact since it just changes the
 121          * exponent).  While the exponent of r is less than or equal
 122          * to (MAX_EXPONENT - 3), the computation should not overflow.
 123          */
 124         java.util.Random rand = new java.util.Random();
 125         for(int i = 0; i < 1000; i++) {
 126             double d = rand.nextDouble();
 127             // Scale d to have an exponent equal to MAX_EXPONENT -15
 128             d = Math.scalb(d, DoubleConsts.MAX_EXPONENT
 129                                  -15 - Tests.ilogb(d));
 130             for(int j = 0; j <= 13; j += 1) {
 131                 failures += testHypotCase(3*d, 4*d, 5*d, 2.5);
 132                 d *= 2.0; // increase exponent by 1
 133             }
 134         }
 135 
 136         // Test for monotonicity failures.  Fix one argument and test
 137         // two numbers before and two numbers after each chosen value;
 138         // i.e.
 139         //
 140         // pcNeighbors[] =
 141         // {nextDown(nextDown(pc)),
 142         // nextDown(pc),
 143         // pc,
 144         // nextUp(pc),
 145         // nextUp(nextUp(pc))}
 146         //
 147         // and we test that hypot(pcNeighbors[i]) <= hypot(pcNeighbors[i+1])
 148         {




   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  * @library /lib/testlibrary
  29  * @build jdk.testlibrary.DoubleUtils jdk.testlibrary.FloatUtils
  30  * @run main HypotTests
  31  * @author Joseph D. Darcy
  32  */
  33 
  34 import static jdk.testlibrary.DoubleUtils.*;
  35 
  36 public class HypotTests {
  37     private HypotTests(){}
  38 
  39     static final double infinityD = Double.POSITIVE_INFINITY;
  40     static final double NaNd      = Double.NaN;
  41 
  42     /**
  43      * Given integers m and n, assuming m < n, the triple (n^2 - m^2,
  44      * 2mn, and n^2 + m^2) is a Pythagorean triple with a^2 + b^2 =
  45      * c^2.  This methods returns a long array holding the Pythagorean
  46      * triple corresponding to the inputs.
  47      */
  48     static long [] pythagoreanTriple(int m, int n) {
  49         long M = m;
  50         long N = n;
  51         long result[] = new long[3];
  52 
  53 
  54         result[0] = Math.abs(M*M - N*N);


  72             {1.0,               NaNd,                   NaNd},
  73             {Double.longBitsToDouble(0x7FF0000000000001L),      1.0,    NaNd},
  74             {Double.longBitsToDouble(0xFFF0000000000001L),      1.0,    NaNd},
  75             {Double.longBitsToDouble(0x7FF8555555555555L),      1.0,    NaNd},
  76             {Double.longBitsToDouble(0xFFF8555555555555L),      1.0,    NaNd},
  77             {Double.longBitsToDouble(0x7FFFFFFFFFFFFFFFL),      1.0,    NaNd},
  78             {Double.longBitsToDouble(0xFFFFFFFFFFFFFFFFL),      1.0,    NaNd},
  79             {Double.longBitsToDouble(0x7FFDeadBeef00000L),      1.0,    NaNd},
  80             {Double.longBitsToDouble(0xFFFDeadBeef00000L),      1.0,    NaNd},
  81             {Double.longBitsToDouble(0x7FFCafeBabe00000L),      1.0,    NaNd},
  82             {Double.longBitsToDouble(0xFFFCafeBabe00000L),      1.0,    NaNd},
  83         };
  84 
  85         for(int i = 0; i < testCases.length; i++) {
  86             failures += testHypotCase(testCases[i][0], testCases[i][1],
  87                                       testCases[i][2]);
  88         }
  89 
  90         // Verify hypot(x, 0.0) is close to x over the entire exponent
  91         // range.
  92         for(int i = MIN_SUB_EXPONENT;
  93             i <= Double.MAX_EXPONENT;
  94             i++) {
  95             double input = Math.scalb(2, i);
  96             failures += testHypotCase(input, 0.0, input);
  97         }
  98 
  99 
 100         // Test Pythagorean triples
 101 
 102         // Small ones
 103         for(int m = 1; m < 10; m++) {
 104             for(int n = m+1; n < 11; n++) {
 105                 long [] result = pythagoreanTriple(m, n);
 106                 failures += testHypotCase(result[0], result[1], result[2]);
 107             }
 108         }
 109 
 110         // Big ones
 111         for(int m = 100000; m < 100100; m++) {
 112             for(int n = m+100000; n < 200200; n++) {
 113                 long [] result = pythagoreanTriple(m, n);
 114                 failures += testHypotCase(result[0], result[1], result[2]);
 115             }
 116         }
 117 
 118         // Approaching overflow tests
 119 
 120         /*
 121          * Create a random value r with an large-ish exponent.  The
 122          * result of hypot(3*r, 4*r) should be approximately 5*r. (The
 123          * computation of 4*r is exact since it just changes the
 124          * exponent).  While the exponent of r is less than or equal
 125          * to (MAX_EXPONENT - 3), the computation should not overflow.
 126          */
 127         java.util.Random rand = new java.util.Random();
 128         for(int i = 0; i < 1000; i++) {
 129             double d = rand.nextDouble();
 130             // Scale d to have an exponent equal to MAX_EXPONENT -15
 131             d = Math.scalb(d, Double.MAX_EXPONENT
 132                                  -15 - Tests.ilogb(d));
 133             for(int j = 0; j <= 13; j += 1) {
 134                 failures += testHypotCase(3*d, 4*d, 5*d, 2.5);
 135                 d *= 2.0; // increase exponent by 1
 136             }
 137         }
 138 
 139         // Test for monotonicity failures.  Fix one argument and test
 140         // two numbers before and two numbers after each chosen value;
 141         // i.e.
 142         //
 143         // pcNeighbors[] =
 144         // {nextDown(nextDown(pc)),
 145         // nextDown(pc),
 146         // pc,
 147         // nextUp(pc),
 148         // nextUp(nextUp(pc))}
 149         //
 150         // and we test that hypot(pcNeighbors[i]) <= hypot(pcNeighbors[i+1])
 151         {