random.java
/*
* Java Genetic Algorithm Library (@__identifier__@).
* Copyright (c) @__year__@ Franz Wilhelmstötter
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Author:
* Franz Wilhelmstötter (franz.wilhelmstoetter@gmx.at)
*/
package org.jenetics.internal.math;
import org.jenetics.util.StaticObject;
/**
* Some random helper functions.
*
* @author <a href="mailto:franz.wilhelmstoetter@gmx.at">Franz Wilhelmstötter</a>
* @since 1.4
* @version 1.4 — <em>$Date: 2014-02-15 $</em>
*/
public final class random extends StaticObject {
private random() {}
/*
* Conversion methods used by the 'Random' engine from the JDK.
*/
public static float toFloat(final int a) {
return (a >>> 8)/((float)(1 << 24));
}
public static float toFloat(final long a) {
return (int)(a >>> 40)/((float)(1 << 24));
}
public static double toDouble(final long a) {
return (((a >>> 38) << 27) + (((int)a) >>> 5))/(double)(1L << 53);
}
public static double toDouble(final int a, final int b) {
return (((long)(a >>> 6) << 27) + (b >>> 5))/(double)(1L << 53);
}
/*
* Conversion methods used by the Apache Commons BitStreamGenerator.
*/
public static float toFloat2(final int a) {
return (a >>> 9)*0x1.0p-23f;
}
public static float toFloat2(final long a) {
return (int)(a >>> 41)*0x1.0p-23f;
}
public static double toDouble2(final long a) {
return (a & 0xFFFFFFFFFFFFFL)*0x1.0p-52d;
}
public static double toDouble2(final int a, final int b) {
return (((long)(a >>> 6) << 26) | (b >>> 6))*0x1.0p-52d;
}
}