83 lines
2.9 KiB
Java
83 lines
2.9 KiB
Java
/*
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* Copyright (C) 2011 The Guava Authors
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package com.google.common.math;
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import static com.google.common.math.MathTesting.ALL_BIGINTEGER_CANDIDATES;
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import static com.google.common.math.MathTesting.FINITE_DOUBLE_CANDIDATES;
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import static com.google.common.math.MathTesting.POSITIVE_FINITE_DOUBLE_CANDIDATES;
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import java.lang.reflect.Method;
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import java.math.BigInteger;
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import junit.framework.TestCase;
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/**
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* Tests for {@link DoubleUtils}.
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*
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* @author Louis Wasserman
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*/
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public class DoubleUtilsTest extends TestCase {
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@AndroidIncompatible // no FpUtils and no Math.nextDown in old versions
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public void testNextDown() throws Exception {
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Method jdkNextDown = getJdkNextDown();
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for (double d : FINITE_DOUBLE_CANDIDATES) {
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assertEquals(jdkNextDown.invoke(null, d), DoubleUtils.nextDown(d));
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}
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}
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private static Method getJdkNextDown() throws Exception {
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try {
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return Math.class.getMethod("nextDown", double.class);
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} catch (NoSuchMethodException expectedBeforeJava8) {
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return Class.forName("sun.misc.FpUtils").getMethod("nextDown", double.class);
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}
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}
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@AndroidIncompatible // TODO(cpovirk): File bug for BigDecimal.doubleValue().
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public void testBigToDouble() {
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for (BigInteger b : ALL_BIGINTEGER_CANDIDATES) {
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if (b.doubleValue() != DoubleUtils.bigToDouble(b)) {
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failFormat(
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"Converting %s to double: expected doubleValue %s but got bigToDouble %s",
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b, b.doubleValue(), DoubleUtils.bigToDouble(b));
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}
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}
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}
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public void testEnsureNonNegative() {
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assertEquals(0.0, DoubleUtils.ensureNonNegative(0.0));
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for (double positiveValue : POSITIVE_FINITE_DOUBLE_CANDIDATES) {
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assertEquals(positiveValue, DoubleUtils.ensureNonNegative(positiveValue));
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assertEquals(0.0, DoubleUtils.ensureNonNegative(-positiveValue));
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}
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assertEquals(Double.POSITIVE_INFINITY, DoubleUtils.ensureNonNegative(Double.POSITIVE_INFINITY));
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assertEquals(0.0, DoubleUtils.ensureNonNegative(Double.NEGATIVE_INFINITY));
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try {
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DoubleUtils.ensureNonNegative(Double.NaN);
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fail("Expected IllegalArgumentException from ensureNonNegative(Double.NaN)");
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} catch (IllegalArgumentException expected) {
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}
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}
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public void testOneBits() {
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assertEquals(DoubleUtils.ONE_BITS, Double.doubleToRawLongBits(1.0));
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}
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private static void failFormat(String template, Object... args) {
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fail(String.format(template, args));
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}
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}
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