- * For a double value {@code x}, this method returns - * {@code +1.0} if {@code x > 0}, {@code 0.0} if - * {@code x = 0.0}, and {@code -1.0} if {@code x < 0}. - * Returns {@code NaN} if {@code x} is {@code NaN}.
- * - * @param x the value, a double - * @return +1.0, 0.0, or -1.0, depending on the sign of x - */ - public static double sign(final double x) { - if (Double.isNaN(x)) { - return Double.NaN; - } - return (x == 0.0) ? 0.0 : (x > 0.0) ? 1.0 : -1.0; - } - - /** - * Returns the sign - * for float value {@code x}. - *- * For a float value x, this method returns +1.0F if x > 0, 0.0F if x = - * 0.0F, and -1.0F if x < 0. Returns {@code NaN} if {@code x} - * is {@code NaN}.
- * - * @param x the value, a float - * @return +1.0F, 0.0F, or -1.0F, depending on the sign of x - */ - public static float sign(final float x) { - if (Float.isNaN(x)) { - return Float.NaN; - } - return (x == 0.0F) ? 0.0F : (x > 0.0F) ? 1.0F : -1.0F; - } - /** * Returns the sign * for int value {@code x}. diff --git a/src/test/java/org/apache/commons/math/util/FastMathTest.java b/src/test/java/org/apache/commons/math/util/FastMathTest.java index f5f5f8df5..89cefbce9 100644 --- a/src/test/java/org/apache/commons/math/util/FastMathTest.java +++ b/src/test/java/org/apache/commons/math/util/FastMathTest.java @@ -25,6 +25,7 @@ import org.apache.commons.math.dfp.DfpField; import org.apache.commons.math.dfp.DfpMath; import org.apache.commons.math.random.MersenneTwister; import org.apache.commons.math.random.RandomGenerator; +import org.apache.commons.math.TestUtils; import org.junit.Assert; import org.junit.Before; import org.junit.Ignore; @@ -1060,4 +1061,21 @@ public class FastMathTest { compareClassMethods( FastMath.class, StrictMath.class); } + @Test + public void testSignumDouble() { + final double delta = 0.0; + Assert.assertEquals(1.0, FastMath.signum(2.0), delta); + Assert.assertEquals(0.0, FastMath.signum(0.0), delta); + Assert.assertEquals(-1.0, FastMath.signum(-2.0), delta); + TestUtils.assertSame(-0. / 0., FastMath.signum(Double.NaN)); + } + + @Test + public void testSignumFloat() { + final float delta = 0.0F; + Assert.assertEquals(1.0F, FastMath.signum(2.0F), delta); + Assert.assertEquals(0.0F, FastMath.signum(0.0F), delta); + Assert.assertEquals(-1.0F, FastMath.signum(-2.0F), delta); + TestUtils.assertSame(Float.NaN, FastMath.signum(Float.NaN)); + } } diff --git a/src/test/java/org/apache/commons/math/util/MathUtilsTest.java b/src/test/java/org/apache/commons/math/util/MathUtilsTest.java index ef129caee..a7b6ade2d 100644 --- a/src/test/java/org/apache/commons/math/util/MathUtilsTest.java +++ b/src/test/java/org/apache/commons/math/util/MathUtilsTest.java @@ -454,24 +454,6 @@ public final class MathUtilsTest { Assert.assertEquals((byte) (-1), MathUtils.sign((byte) (-2))); } - @Test - public void testSignDouble() { - double delta = 0.0; - Assert.assertEquals(1.0, MathUtils.sign(2.0), delta); - Assert.assertEquals(0.0, MathUtils.sign(0.0), delta); - Assert.assertEquals(-1.0, MathUtils.sign(-2.0), delta); - TestUtils.assertSame(-0. / 0., MathUtils.sign(Double.NaN)); - } - - @Test - public void testSignFloat() { - float delta = 0.0F; - Assert.assertEquals(1.0F, MathUtils.sign(2.0F), delta); - Assert.assertEquals(0.0F, MathUtils.sign(0.0F), delta); - Assert.assertEquals(-1.0F, MathUtils.sign(-2.0F), delta); - TestUtils.assertSame(Float.NaN, MathUtils.sign(Float.NaN)); - } - @Test public void testSignInt() { Assert.assertEquals(1, MathUtils.sign(2));