Repository: commons-math Updated Branches: refs/heads/master 4742149a8 -> 9d4fb4952
Reverting commit 4cbb388ba9099be121f81d75000acc3af93bf993 as per Gilles request. The work on revamping the random packages is perfoemd in the random-ravamp branch. Project: http://git-wip-us.apache.org/repos/asf/commons-math/repo Commit: http://git-wip-us.apache.org/repos/asf/commons-math/commit/9d4fb495 Tree: http://git-wip-us.apache.org/repos/asf/commons-math/tree/9d4fb495 Diff: http://git-wip-us.apache.org/repos/asf/commons-math/diff/9d4fb495 Branch: refs/heads/master Commit: 9d4fb495265055724c2dfc2efa05460ee36fc2cf Parents: 3c2fede Author: Luc Maisonobe <l...@apache.org> Authored: Sun Jan 17 11:35:25 2016 +0100 Committer: Luc Maisonobe <l...@apache.org> Committed: Sun Jan 17 11:40:27 2016 +0100 ---------------------------------------------------------------------- .../math4/random/BaseRandomGenerator.java | 270 ------------------- .../math4/random/BaseRandomGeneratorTest.java | 129 --------- 2 files changed, 399 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/commons-math/blob/9d4fb495/src/main/java/org/apache/commons/math4/random/BaseRandomGenerator.java ---------------------------------------------------------------------- diff --git a/src/main/java/org/apache/commons/math4/random/BaseRandomGenerator.java b/src/main/java/org/apache/commons/math4/random/BaseRandomGenerator.java deleted file mode 100644 index a78fd38..0000000 --- a/src/main/java/org/apache/commons/math4/random/BaseRandomGenerator.java +++ /dev/null @@ -1,270 +0,0 @@ -/* - * 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 org.apache.commons.math4.exception.NotStrictlyPositiveException; -import org.apache.commons.math4.exception.OutOfRangeException; -import org.apache.commons.math4.util.FastMath; - -/** - * Abstract class implementing the methods of the {@link RandomGenerator} - * interface in a generic way on the basis of abstract method {@link nextInt()} - * to be defined in subclasses. - * - * It also provides additional utility methods that are not part of the - * {@link RandomGenerator} API. - * - * @since 4.0 - */ -public abstract class BaseRandomGenerator - implements RandomGenerator, - Serializable { - /** Identifier for serialization. */ - private static final long serialVersionUID = 20151227L; - /** Next Gaussian. */ - private double nextGaussian = Double.NaN; - - /** - * {@inheritDoc} - * - * Basic building block for all the generic methods defined in this class. - * It produces the next random number according to a specific algorithm to - * be implemented by a subclass. - */ - @Override - public abstract int nextInt(); - - /** {@inheritDoc} */ - @Override - public boolean nextBoolean() { - return (nextInt() >>> 31) != 0; - } - - /** {@inheritDoc} */ - @Override - public double nextDouble() { - final long high = ((long) (nextInt() >>> 6)) << 26; - final int low = nextInt() >>> 6; - return (high | low) * 0x1.0p-52d; - } - - /** {@inheritDoc} */ - @Override - public float nextFloat() { - return (nextInt() >>> 9) * 0x1.0p-23f; - } - - /** {@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} - * - * <p> - * This default implementation is copied from Apache Harmony - * java.util.Random (r929253). - * </p> - * - * <p>Implementation notes: - * <ul> - * <li>If n is a power of 2, this method returns - * {@code (int) ((n * (long) next(31)) >> 31)}.</li> - * <li>If n is not a power of 2, what is returned is {@code next(31) % n} - * with {@code next(31)} values rejected (i.e. regenerated) until a - * value that is larger than the remainder of {@code Integer.MAX_VALUE / n} - * is generated. Rejection of this initial segment is necessary to ensure - * a uniform distribution.</li> - * </ul> - * </p> - */ - @Override - public int nextInt(int n) throws IllegalArgumentException { - if (n > 0) { - if ((n & -n) == n) { - return (int) ((n * (long) (nextInt() >>> 1)) >> 31); - } - int bits; - int val; - do { - bits = (nextInt() >>> 1); - val = bits % n; - } while (bits - val + (n - 1) < 0); - return val; - } - - throw new NotStrictlyPositiveException(n); - } - - /** {@inheritDoc} */ - @Override - public long nextLong() { - final long high = ((long) nextInt()) << 32; - final long low = nextInt() & 0xffffffffL; - return high | low; - } - - /** - * Returns a pseudorandom, uniformly distributed {@code long} 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 {@code long} value - * between 0 (inclusive) and n (exclusive). - * @throws IllegalArgumentException if n is not positive. - */ - public long nextLong(long n) { - if (n > 0) { - long bits; - long val; - do { - bits = ((long) (nextInt() >>> 1)) << 32; - bits |= ((long) nextInt()) & 0xffffffffL; - val = bits % n; - } while (bits - val + (n - 1) < 0); - return val; - } - - throw new NotStrictlyPositiveException(n); - } - - /** - * Clears the cache used by the default implementation of - * {@link #nextGaussian}. - */ - public void clear() { - nextGaussian = Double.NaN; - } - - /** - * Generates random bytes and places them into a user-supplied array. - * - * <p> - * The array is filled with bytes extracted from random integers generated - * using {@link #nextInt()}. - * This implies that the number of random bytes generated may be larger than - * the length of the byte array. - * </p> - * - * @param bytes Array in which to put the generated bytes. Cannot be {@code null}. - */ - @Override - public void nextBytes(byte[] bytes) { - nextBytesFill(bytes, 0, bytes.length); - } - - /** - * Generates random bytes and places them into a user-supplied array. - * - * <p> - * The array is filled with bytes extracted from random integers generated - * using {@link #nextInt()}. - * This implies that the number of random bytes generated may be larger than - * the length of the byte array. - * </p> - * - * @param bytes Array in which to put the generated bytes. Cannot be {@code null}. - * @param start Index at which to start inserting the generated bytes. - * @param len Number of bytes to insert. - * @throws OutOfRangeException if {@code start < 0} or {@code start >= bytes.length}. - * @throws OutOfRangeException if {@code len <= 0} or {@code len > bytes.length - start}. - */ - public void nextBytes(byte[] bytes, - int start, - int len) { - if (start < 0 || - start >= bytes.length) { - throw new OutOfRangeException(start, 0, bytes.length); - } - final int max = bytes.length - start; - if (len <= 0 || - len > max) { - throw new OutOfRangeException(len, 0, max); - } - - nextBytesFill(bytes, start, len); - } - - /** - * Generates random bytes and places them into a user-supplied array. - * - * <p> - * The array is filled with bytes extracted from random integers generated - * using {@link #nextInt()}. - * This implies that the number of random bytes generated may be larger than - * the length of the byte array. - * </p> - * - * @param bytes Array in which to put the generated bytes. Cannot be {@code null}. - * @param position Index at which to start inserting the generated bytes. - * @param length Number of bytes to insert. - */ - private void nextBytesFill(byte[] bytes, - int position, - int length) { - int index = position; // Index of first insertion. - - // Index of first insertion plus multiple 4 part of length (i.e. length - // with two least significant bits unset). - final int indexLoopLimit = index + (length & 0x7ffffffc); - - // Start filling in the byte array, 4 bytes at a time. - while (index < indexLoopLimit) { - final int random = nextInt(); - bytes[index++] = (byte) random; - bytes[index++] = (byte) (random >>> 8); - bytes[index++] = (byte) (random >>> 16); - bytes[index++] = (byte) (random >>> 24); - } - - final int indexLimit = position + length; // Index of last insertion + 1. - - // Fill in the remaining bytes. - if (index < indexLimit) { - int random = nextInt(); - while (true) { - bytes[index++] = (byte) random; - if (index < indexLimit) { - random >>>= 8; - } else { - break; - } - } - } - } -} http://git-wip-us.apache.org/repos/asf/commons-math/blob/9d4fb495/src/test/java/org/apache/commons/math4/random/BaseRandomGeneratorTest.java ---------------------------------------------------------------------- diff --git a/src/test/java/org/apache/commons/math4/random/BaseRandomGeneratorTest.java b/src/test/java/org/apache/commons/math4/random/BaseRandomGeneratorTest.java deleted file mode 100644 index 40ab9b5..0000000 --- a/src/test/java/org/apache/commons/math4/random/BaseRandomGeneratorTest.java +++ /dev/null @@ -1,129 +0,0 @@ -/* - * 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.util.Random; - -import org.apache.commons.math4.exception.OutOfRangeException; - -import org.junit.Assert; -import org.junit.Before; -import org.junit.Test; - -/** - * Tests for the generic implementations of the methods defined in the - * {@link BaseRandomGenerator} class, using the standard {@link Random} - * class as the source of randomness. - */ -public class BaseRandomGeneratorTest extends RandomGeneratorAbstractTest { - /** To simplify testing of additional utility methods. */ - protected BaseRandomGenerator baseRandomGenerator; - - @Before - public void setUp() { - baseRandomGenerator = (BaseRandomGenerator) generator; - } - - @Override - protected RandomGenerator makeGenerator() { - final RandomGenerator generator = new TestGenerator(); - generator.setSeed(1000); - return generator; - } - - @Test(expected=OutOfRangeException.class) - public void testNextBytesPrecondition1() { - final int len = 3; - final byte[] b = new byte[len]; - baseRandomGenerator.nextBytes(b, -1, 1); - } - - @Test(expected=OutOfRangeException.class) - public void testNextBytesPrecondition2() { - final int len = 3; - final byte[] b = new byte[len]; - baseRandomGenerator.nextBytes(b, len, 0); - } - - @Test(expected=OutOfRangeException.class) - public void testNextBytesPrecondition3() { - final int len = 3; - final byte[] b = new byte[len]; - baseRandomGenerator.nextBytes(b, 0, 0); - } - - @Test(expected=OutOfRangeException.class) - public void testNextBytesPrecondition4() { - final int len = 3; - final byte[] b = new byte[len]; - baseRandomGenerator.nextBytes(b, 0, len + 1); - } - - @Test - public void testNextBytesSubArray() { - final int size = 123; - final int insert = 72; - final int len = 37; - - final byte[] buffer = new byte[size]; - baseRandomGenerator.nextBytes(buffer, insert, len); - - final byte[] bufferCopy = buffer.clone(); - baseRandomGenerator.nextBytes(buffer, insert, len); - - for (int i = 0; i < insert; i++) { - Assert.assertEquals(bufferCopy[i], buffer[i]); - } - final int maxInsert = insert + len; - for (int i = insert; i < maxInsert; i++) { - Assert.assertNotEquals(bufferCopy[i], buffer[i]); - } - for (int i = maxInsert; i < size; i++) { - Assert.assertEquals(bufferCopy[i], buffer[i]); - } - } - - /** - * Test RNG delegating to {@link Random}. - */ - private static class TestGenerator extends BaseRandomGenerator { - /** Delegate. */ - private Random random = new Random(); - - @Override - public void setSeed(int seed) { - random.setSeed(seed); - clear(); - } - - @Override - public void setSeed(int[] seed) { - random.setSeed(seed[0]); - } - - @Override - public void setSeed(long seed) { - random.setSeed((int) seed); - } - - @Override - public int nextInt() { - // Delegate. - return random.nextInt(); - } - } -}
