| /* Copyright (c) 2006-2009 Jan S. Rellermeyer |
| * Systems Group, |
| * Department of Computer Science, ETH Zurich. |
| * 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 ETH 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. |
| */ |
| package ch.ethz.iks.util; |
| |
| /** |
| * Math utilities. |
| * |
| * @author Jan S. Rellermeyer, ETH Zürich |
| * @since 0.2 |
| */ |
| public final class MathUtils { |
| |
| /** |
| * hidden default constructor. |
| */ |
| private MathUtils() { |
| |
| } |
| |
| /** |
| * get the logarithm with base 2. |
| * |
| * @param num |
| * the value. |
| * @return the logarithm. |
| * @since 0.2 |
| */ |
| public static int log2(final int num) { |
| int i = num; |
| int j = -1; |
| while (i > 0) { |
| i = i >> 1; |
| j++; |
| } |
| return j; |
| } |
| |
| /** |
| * get the lower 32 bits of a long value. |
| * |
| * @param val |
| * the long value. |
| * @return the lower 32 bits. |
| * @since 0.2 |
| */ |
| public static long lower32(final long val) { |
| return val & 0xFFFFFFFFL; |
| } |
| |
| /** |
| * get the higher 32 bits of a long value. |
| * |
| * @param val |
| * the long value. |
| * @return the higher 32 bits. |
| * @since 0.2 |
| */ |
| public static long higher32(final long val) { |
| return val >>> 32; |
| } |
| |
| /** |
| * get the absolute value of a long. |
| * |
| * @param val |
| * the (signed) long value. |
| * @return the absolute value. |
| * @since 0.2 |
| */ |
| public static long abs(final long val) { |
| if (val < 0) { |
| return -1 * val; |
| } |
| return val; |
| } |
| |
| /** |
| * get the maximum within an array of long values. |
| * |
| * @param values |
| * the array of long values. |
| * @return the maximum. |
| * @since 0.2 |
| */ |
| public static long max(final long[] values) { |
| long max = values[0]; |
| for (int i = 1; i < values.length; i++) { |
| if (max < values[i]) { |
| max = values[i]; |
| } |
| } |
| return max; |
| } |
| |
| /** |
| * get the minimum within an array of long values. |
| * |
| * @param values |
| * the array of long values. |
| * @return the minimum. |
| * @since 0.2 |
| */ |
| public static long min(final long[] values) { |
| long min = values[0]; |
| for (int i = 1; i < values.length; i++) { |
| if (min > values[i]) { |
| min = values[i]; |
| } |
| } |
| return min; |
| } |
| } |