1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 package org.apache.commons.rng.core.source64; 19 20 /** 21 * A large-state 64-bit generator suitable for {@code double} generation. This is slightly faster 22 * than the all-purpose generator {@link XoRoShiRo1024PlusPlus}. 23 * 24 * <p>This is a member of the Xor-Shift-Rotate family of generators. Memory footprint is 1024 bits 25 * and the period is 2<sup>1024</sup>-1.</p> 26 * 27 * @see <a href="http://xorshift.di.unimi.it/xoroshiro1024star.c">Original source code</a> 28 * @see <a href="http://xoshiro.di.unimi.it/">xorshiro / xoroshiro generators</a> 29 * @since 1.3 30 */ 31 public class XoRoShiRo1024Star extends AbstractXoRoShiRo1024 { 32 /** 33 * Creates a new instance. 34 * 35 * @param seed Initial seed. 36 * If the length is larger than 16, only the first 16 elements will 37 * be used; if smaller, the remaining elements will be automatically 38 * set. A seed containing all zeros will create a non-functional generator. 39 */ 40 public XoRoShiRo1024Star(long[] seed) { 41 super(seed); 42 } 43 44 /** 45 * Creates a copy instance. 46 * 47 * @param source Source to copy. 48 */ 49 protected XoRoShiRo1024Star(XoRoShiRo1024Star source) { 50 super(source); 51 } 52 53 /** {@inheritDoc} */ 54 @Override 55 protected long transform(long s0, long s15) { 56 return s0 * 0x9e3779b97f4a7c13L; 57 } 58 59 /** {@inheritDoc} */ 60 @Override 61 protected XoRoShiRo1024Star copy() { 62 // This exists to ensure the jump function returns 63 // the correct class type. It should not be public. 64 return new XoRoShiRo1024Star(this); 65 } 66 }