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Diffstat (limited to 'src/main/java/org/apache/commons/math/random/RandomAdaptor.java')
| -rw-r--r-- | src/main/java/org/apache/commons/math/random/RandomAdaptor.java | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/src/main/java/org/apache/commons/math/random/RandomAdaptor.java b/src/main/java/org/apache/commons/math/random/RandomAdaptor.java new file mode 100644 index 0000000..8091a48 --- /dev/null +++ b/src/main/java/org/apache/commons/math/random/RandomAdaptor.java @@ -0,0 +1,198 @@ +/* + * 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.math.random; + +import java.util.Random; + +/** + * Extension of <code>java.util.Random</code> wrapping a + * {@link RandomGenerator}. + * + * @since 1.1 + * @version $Revision: 1003886 $ $Date: 2010-10-02 23:04:44 +0200 (sam. 02 oct. 2010) $ + */ +public class RandomAdaptor extends Random implements RandomGenerator { + + /** Serializable version identifier. */ + private static final long serialVersionUID = 2306581345647615033L; + + /** Wrapped randomGenerator instance */ + private final RandomGenerator randomGenerator; + + /** + * Prevent instantiation without a generator argument + */ + @SuppressWarnings("unused") + private RandomAdaptor() { randomGenerator = null; } + + /** + * Construct a RandomAdaptor wrapping the supplied RandomGenerator. + * + * @param randomGenerator the wrapped generator + */ + public RandomAdaptor(RandomGenerator randomGenerator) { + this.randomGenerator = randomGenerator; + } + + /** + * Factory method to create a <code>Random</code> using the supplied + * <code>RandomGenerator</code>. + * + * @param randomGenerator wrapped RandomGenerator instance + * @return a Random instance wrapping the RandomGenerator + */ + public static Random createAdaptor(RandomGenerator randomGenerator) { + return new RandomAdaptor(randomGenerator); + } + + /** + * Returns the next pseudorandom, uniformly distributed + * <code>boolean</code> value from this random number generator's + * sequence. + * + * @return the next pseudorandom, uniformly distributed + * <code>boolean</code> value from this random number generator's + * sequence + */ + @Override + public boolean nextBoolean() { + return randomGenerator.nextBoolean(); + } + + /** + * Generates random bytes and places them into a user-supplied + * byte array. The number of random bytes produced is equal to + * the length of the byte array. + * + * @param bytes the non-null byte array in which to put the + * random bytes + */ + @Override + public void nextBytes(byte[] bytes) { + randomGenerator.nextBytes(bytes); + } + + /** + * Returns the next pseudorandom, uniformly distributed + * <code>double</code> value between <code>0.0</code> and + * <code>1.0</code> from this random number generator's sequence. + * + * @return the next pseudorandom, uniformly distributed + * <code>double</code> value between <code>0.0</code> and + * <code>1.0</code> from this random number generator's sequence + */ + @Override + public double nextDouble() { + return randomGenerator.nextDouble(); + } + + /** + * Returns the next pseudorandom, uniformly distributed <code>float</code> + * value between <code>0.0</code> and <code>1.0</code> from this random + * number generator's sequence. + * + * @return the next pseudorandom, uniformly distributed <code>float</code> + * value between <code>0.0</code> and <code>1.0</code> from this + * random number generator's sequence + */ + @Override + public float nextFloat() { + return randomGenerator.nextFloat(); + } + + /** + * Returns the next pseudorandom, Gaussian ("normally") distributed + * <code>double</code> value with mean <code>0.0</code> and standard + * deviation <code>1.0</code> from this random number generator's sequence. + * + * @return the next pseudorandom, Gaussian ("normally") distributed + * <code>double</code> value with mean <code>0.0</code> and + * standard deviation <code>1.0</code> from this random number + * generator's sequence + */ + @Override + public double nextGaussian() { + return randomGenerator.nextGaussian(); + } + + /** + * Returns the next pseudorandom, uniformly distributed <code>int</code> + * value from this random number generator's sequence. + * All 2<font size="-1"><sup>32</sup></font> possible <tt>int</tt> values + * should be produced with (approximately) equal probability. + * + * @return the next pseudorandom, uniformly distributed <code>int</code> + * value from this random number generator's sequence + */ + @Override + public int nextInt() { + return randomGenerator.nextInt(); + } + + /** + * Returns a pseudorandom, uniformly distributed <tt>int</tt> value + * between 0 (inclusive) and the specified value (exclusive), drawn from + * this random number generator's sequence. + * + * @param n the bound on the random number to be returned. Must be + * positive. + * @return a pseudorandom, uniformly distributed <tt>int</tt> + * value between 0 (inclusive) and n (exclusive). + * @throws IllegalArgumentException if n is not positive. + */ + @Override + public int nextInt(int n) { + return randomGenerator.nextInt(n); + } + + /** + * Returns the next pseudorandom, uniformly distributed <code>long</code> + * value from this random number generator's sequence. All + * 2<font size="-1"><sup>64</sup></font> possible <tt>long</tt> values + * should be produced with (approximately) equal probability. + * + * @return the next pseudorandom, uniformly distributed <code>long</code> + *value from this random number generator's sequence + */ + @Override + public long nextLong() { + return randomGenerator.nextLong(); + } + + /** {@inheritDoc} */ + public void setSeed(int seed) { + if (randomGenerator != null) { // required to avoid NPE in constructor + randomGenerator.setSeed(seed); + } + } + + /** {@inheritDoc} */ + public void setSeed(int[] seed) { + if (randomGenerator != null) { // required to avoid NPE in constructor + randomGenerator.setSeed(seed); + } + } + + /** {@inheritDoc} */ + @Override + public void setSeed(long seed) { + if (randomGenerator != null) { // required to avoid NPE in constructor + randomGenerator.setSeed(seed); + } + } + +} |