org.jpedal.utils.FastMath Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of OpenViewerFX Show documentation
An Open Source JavaFX PDF Viewer
The newest version!
/*
 * ===========================================
 * Java Pdf Extraction Decoding Access Library
 * ===========================================
 *
 * Project Info:  http://www.idrsolutions.com
 * Help section for developers at http://www.idrsolutions.com/support/
 *
 * (C) Copyright 1997-2015 IDRsolutions and Contributors.
 *
 * This file is part of JPedal/JPDF2HTML5
 *
     This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library 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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA


 *
 * ---------------
 * FastMath.java
 * ---------------
 */
package org.jpedal.utils;

/**
 * This class is used to handle computationally fastest mathematics formulas and
 * does not guarantee accurate output
 *
 * @author suda
 */
public class FastMath {

    /**
     * return the square root of c, computed using Newton's method
     *
     * @param a
     * @return
     */
    public static double sqrt(double a) {
        if (a < 0) {
            return Double.NaN;
        }
        final double e = 1E-15;
        double t = a;
        while (Math.abs(t - a / t) > e * t) {
            t = (a / t + t) / 2.0;
        }
        return t;
    }

    /**
     * not 100% accurate ,dont use in negative values     *
     * @param x
     * @param n
     * @return
     */
    public static final int pow(int x, int n) {
        if(n==0){
            return 1;
        }
        int a = x;
        for (int i = 1; i < n; i++) {
            a *= x;
        }
        return a;
    }

    /**
     * not 100% accurate ,dont use in negative values     *
     * @param x
     * @param n
     * @return
     */
    public static final float pow(float x, int n) {
        if(n==0){
            return 1;
        }
        float a = x;
        for (int i = 1; i < n; i++) {
            a *= x;
        }
        return a;
    }

    /**
     * not 100% accurate ,dont use in negative values     *
     * @param x
     * @param n
     * @return
     */
    public static final double pow(double x, int n) {
        if(n==0){
            return 1;
        }
        double a = x;
        for (int i = 1; i < n; i++) {
            a *= x;
        }
        return a;
    }

}