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 package org.apache.commons.rng.sampling.distribution; 18 19 import org.apache.commons.rng.UniformRandomProvider; 20 21 /** 22 * Sampling from a uniform distribution. 23 * 24 * @since 1.0 25 */ 26 public class ContinuousUniformSampler 27 extends SamplerBase 28 implements ContinuousSampler { 29 /** Lower bound. */ 30 private final double lo; 31 /** Higher bound. */ 32 private final double hi; 33 /** Underlying source of randomness. */ 34 private final UniformRandomProvider rng; 35 36 /** 37 * @param rng Generator of uniformly distributed random numbers. 38 * @param lo Lower bound. 39 * @param hi Higher bound. 40 */ 41 public ContinuousUniformSampler(UniformRandomProvider rng, 42 double lo, 43 double hi) { 44 super(null); 45 this.rng = rng; 46 this.lo = lo; 47 this.hi = hi; 48 } 49 50 /** {@inheritDoc} */ 51 @Override 52 public double sample() { 53 final double u = rng.nextDouble(); 54 return u * hi + (1 - u) * lo; 55 } 56 57 /** {@inheritDoc} */ 58 @Override 59 public String toString() { 60 return "Uniform deviate [" + rng.toString() + "]"; 61 } 62 }