/* 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 Z�rich
* @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;
}
}