import java.io.File;
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF 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.
*
*
*/
public class Main {
/**
* For a double precision value x, this method returns +1.0 if x >= 0 and
* -1.0 if x < 0. Returns NaN if x is
* NaN.
*
* @param x the value, a double
* @return +1.0 or -1.0, depending on the sign of x
*/
public static double indicator(final double x) {
if (Double.isNaN(x)) {
return Double.NaN;
}
return (x >= 0.0) ? 1.0 : -1.0;
}
}