Calculates e^x, faster but less accurate than MathUtil#exp(double) - Java java.lang

Java examples for java.lang:Math Calculation

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Description

Calculates e^x, faster but less accurate than MathUtil#exp(double)

Demo Code

/*//from   ww  w  . j  av a  2 s  .c  o m
 * Created on 02-May-2006 at 17:31:01.
 * 
 * Copyright (c) 2010 Robert Virkus / Enough Software
 *
 * This file is part of J2ME Polish.
 *
 * J2ME Polish is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * J2ME Polish is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with J2ME Polish; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 * 
 * Commercial licenses are also available, please
 * refer to the accompanying LICENSE.txt or visit
 * http://www.j2mepolish.org for details.
 */
//package com.java2s;

public class Main {
    /**
     * Calculates e^x, faster but less accurate than {@link MathUtil#exp(double)}
     * @param x x
     * @return e^x
     */
    public static double fastexp(double x) {
        return (362880 + x
                * (362880 + x
                        * (181440 + x
                                * (60480 + x
                                        * (15120 + x
                                                * (3024 + x
                                                        * (504 + x
                                                                * (72 + x
                                                                        * (9 + x))))))))) * 2.75573192e-6;
    }
}

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