Here you can find the source of signum(double value)
public static int signum(double value)
//package com.java2s; /*/*from ww w . ja va 2 s .c om*/ * ============================================================================= * Simplified BSD License, see http://www.opensource.org/licenses/ * ----------------------------------------------------------------------------- * Copyright (c) 2008-2009, Marco Terzer, Zurich, Switzerland * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * * Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * Neither the name of the Swiss Federal Institute of Technology Zurich * nor the names of its contributors may be used to endorse or promote * products derived from this software without specific prior written * permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ============================================================================= */ public class Main { /** * Returns the signum of the long value, i.e. 1/-1/0 for a positive, * negative or zero value * * @see Math#signum(double) */ public static int signum(double value) { return (int) Math.signum(value); } /** * Returns the signum of the int value, i.e. 1/-1/0 for a positive, * negative or zero value * * @see Math#signum(float) */ public static int signum(float value) { return (int) Math.signum(value); } }