001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 018package org.apache.commons.rng.core.source64; 019 020/** 021 * A large-state 64-bit generator suitable for {@code double} generation. This is slightly faster 022 * than the all-purpose generator {@link XoRoShiRo1024PlusPlus}. 023 * 024 * <p>This is a member of the Xor-Shift-Rotate family of generators. Memory footprint is 1024 bits 025 * and the period is 2<sup>1024</sup>-1.</p> 026 * 027 * @see <a href="http://xorshift.di.unimi.it/xoroshiro1024star.c">Original source code</a> 028 * @see <a href="http://xoshiro.di.unimi.it/">xorshiro / xoroshiro generators</a> 029 * @since 1.3 030 */ 031public class XoRoShiRo1024Star extends AbstractXoRoShiRo1024 { 032 /** 033 * Creates a new instance. 034 * 035 * @param seed Initial seed. 036 * If the length is larger than 16, only the first 16 elements will 037 * be used; if smaller, the remaining elements will be automatically 038 * set. A seed containing all zeros will create a non-functional generator. 039 */ 040 public XoRoShiRo1024Star(long[] seed) { 041 super(seed); 042 } 043 044 /** 045 * Creates a copy instance. 046 * 047 * @param source Source to copy. 048 */ 049 protected XoRoShiRo1024Star(XoRoShiRo1024Star source) { 050 super(source); 051 } 052 053 /** {@inheritDoc} */ 054 @Override 055 protected long transform(long s0, long s15) { 056 return s0 * 0x9e3779b97f4a7c13L; 057 } 058 059 /** {@inheritDoc} */ 060 @Override 061 protected XoRoShiRo1024Star copy() { 062 // This exists to ensure the jump function returns 063 // the correct class type. It should not be public. 064 return new XoRoShiRo1024Star(this); 065 } 066}