| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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. |
| */ |
| package org.apache.commons.math4.random; |
| |
| import java.io.Serializable; |
| import java.io.IOException; |
| import java.io.ObjectOutputStream; |
| import java.io.ObjectInputStream; |
| import org.apache.commons.math4.util.FastMath; |
| import org.apache.commons.rng.RestorableUniformRandomProvider; |
| import org.apache.commons.rng.RandomSource; |
| |
| /** |
| * Adaptor that delegates to a {@link UniformRandomProvider} instance. |
| * <p> |
| * It is provided for users who wish to test the new RNG implementations |
| * the <i>current</i> generators (up to version 3.6 of Commons Math) in |
| * codes that require the {@code RandomGenerator} interface. |
| * </p> |
| * <p> |
| * Applications should upgrade to use the new generators ASAP. |
| * If problems are found that jeopardize the upgrade, please report them |
| * on the project's |
| * <a href="https://issues.apache.org/jira/browse/MATH"> |
| * issue tracking system</a>. |
| * </p> |
| * |
| * <p> |
| * <b>Notes:</b> |
| * <ul> |
| * <li> |
| * The |
| * {@link RandomGenerator#setSeed(int) setSeed(int)}, |
| * {@link RandomGenerator#setSeed(int[]) setSeed(int[])} and |
| * {@link RandomGenerator#setSeed(long) setSeed(long)} |
| * methods of the {@link RandomGenerator} are not part of the |
| * {@link UniformRandomProvider new API}. |
| * </li> |
| * <li> |
| * The new RNG implementations are not {@code Serializable}. |
| * Use {@link RestorableUniformRandomProvider#saveState()} |
| * instead. |
| * </li> |
| * <li> |
| * {@link RandomGenerator#nextGaussian() nextGaussian()} is not |
| * part of the {@link UniformRandomProvider new API} as it defines |
| * a "post-processing" of the output of a <i>uniform</i> RNG in |
| * order to follow a different distribution. |
| * </li> |
| * </p> |
| * |
| * @since 4.0 |
| * |
| * @deprecated As of 4.0. This class is made available for testing |
| * the {@link RandomSource new RNG implementations} in existing |
| * applications. |
| * It will be removed in the next major release. |
| */ |
| @Deprecated |
| public final class RngAdaptor |
| implements RandomGenerator, |
| Serializable { |
| /** Serializable version identifier. */ |
| private static final long serialVersionUID = 12345L; |
| /** Source. */ |
| private final RandomSource source; |
| /** Delegate. */ |
| private transient RestorableUniformRandomProvider delegate; |
| /** Next gaussian. */ |
| private double nextGaussian = Double.NaN; |
| |
| /** |
| * Creates a new instance. |
| * |
| * @param source Source of randomness. |
| */ |
| public RngAdaptor(RandomSource source) { |
| this(source, null); |
| } |
| |
| /** |
| * Creates a new instance. |
| * |
| * @param source Source of randomness. |
| * @param seed Seed. Can be {@code null}. |
| */ |
| public RngAdaptor(RandomSource source, |
| Object seed) { |
| this.source = source; |
| delegate = RandomSource.create(source, seed); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public void setSeed(int seed) { |
| delegate = RandomSource.create(source, seed); |
| clear(); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public void setSeed(int[] seed) { |
| delegate = RandomSource.create(source, seed); |
| clear(); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public void setSeed(long seed) { |
| delegate = RandomSource.create(source, seed); |
| clear(); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public boolean nextBoolean() { |
| return delegate.nextBoolean(); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public void nextBytes(byte[] bytes) { |
| delegate.nextBytes(bytes); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public double nextDouble() { |
| return delegate.nextDouble(); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public float nextFloat() { |
| return delegate.nextFloat(); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public double nextGaussian() { |
| final double random; |
| if (Double.isNaN(nextGaussian)) { |
| // generate a new pair of gaussian numbers |
| final double x = nextDouble(); |
| final double y = nextDouble(); |
| final double alpha = 2 * FastMath.PI * x; |
| final double r = FastMath.sqrt(-2 * FastMath.log(y)); |
| random = r * FastMath.cos(alpha); |
| nextGaussian = r * FastMath.sin(alpha); |
| } else { |
| // use the second element of the pair already generated |
| random = nextGaussian; |
| nextGaussian = Double.NaN; |
| } |
| |
| return random; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public int nextInt() { |
| return delegate.nextInt(); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public int nextInt(int n) { |
| return delegate.nextInt(n); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public long nextLong() { |
| return delegate.nextLong(); |
| } |
| |
| /** |
| * Clears the cache used by the default implementation of |
| * {@link #nextGaussian}. |
| */ |
| private void clear() { |
| nextGaussian = Double.NaN; |
| } |
| |
| /** |
| * @param out Output stream. |
| * @throws IOException if an error occurs. |
| */ |
| private void writeObject(ObjectOutputStream out) |
| throws IOException { |
| // Write non-transient fields. |
| out.defaultWriteObject(); |
| |
| // Save current state. |
| out.writeObject(((RandomSource.State) delegate.saveState()).getState()); |
| } |
| |
| /** |
| * @param in Input stream. |
| * @throws IOException if an error occurs. |
| * @throws ClassNotFoundException if an error occurs. |
| */ |
| private void readObject(ObjectInputStream in) |
| throws IOException, |
| ClassNotFoundException { |
| // Read non-transient fields. |
| in.defaultReadObject(); |
| |
| // Recreate the "delegate" from serialized info. |
| delegate = RandomSource.create(source); |
| // And restore its state. |
| final RandomSource.State state = new RandomSource.State((byte[]) in.readObject()); |
| delegate.restoreState(state); |
| } |
| } |