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* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch licenses this file to you under
* the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.elasticsearch.test.hamcrest;
public class DoubleMatcher {
/**
* Better floating point comparisons courtesy of https://github.com/brazzy/floating-point-gui.de
*
* Snippet adapted to use doubles instead of floats
*/
public static boolean nearlyEqual(double a, double b, double epsilon) {
final double absA = Math.abs(a);
final double absB = Math.abs(b);
final double diff = Math.abs(a - b);
if (a == b) { // shortcut, handles infinities
return true;
} else if (a == 0 || b == 0 || diff < Double.MIN_NORMAL) {
// a or b is zero or both are extremely close to it
// relative error is less meaningful here
return diff < (epsilon * Double.MIN_NORMAL);
} else { // use relative error
return diff / Math.min((absA + absB), Double.MAX_VALUE) < epsilon;
}
}
}