Rounds a double precision value to the given precision. - Java java.lang

Java examples for java.lang:Math Value

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Description

Rounds a double precision value to the given precision.

Demo Code

/*// w  ww  . ja v a  2 s.  c  o  m
 * Copyright (c) 2006-2011 Karsten Schmidt
 * 
 * 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.
 * 
 * http://creativecommons.org/licenses/LGPL/2.1/
 * 
 * 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */
//package com.java2s;

public class Main {
    /**
     * Rounds a double precision value to the given precision.
     * 
     * @param val
     * @param prec
     * @return rounded value
     */
    public static final double roundTo(double val, double prec) {
        return floor(val / prec + 0.5) * prec;
    }

    /**
     * Rounds a single precision value to the given precision.
     * 
     * @param val
     * @param prec
     * @return rounded value
     */
    public static final float roundTo(float val, float prec) {
        return floor(val / prec + 0.5f) * prec;
    }

    /**
     * Rounds an integer value to the given precision.
     * 
     * @param val
     * @param prec
     * @return rounded value
     */
    public static final int roundTo(int val, int prec) {
        return floor((float) val / prec + 0.5f) * prec;
    }

    public static final int floor(double x) {
        int y = (int) x;
        if (x < 0 && x != y) {
            y--;
        }
        return y;
    }

    /**
     * This method is a *lot* faster than using (int)Math.floor(x).
     * 
     * @param x
     *            value to be floored
     * @return floored value as integer
     * @since 0012
     */
    public static final int floor(float x) {
        int y = (int) x;
        if (x < 0 && x != y) {
            y--;
        }
        return y;
    }
}

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