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Diffstat (limited to 'src/main/java/org/apache/commons/math/random/RandomGenerator.java')
| -rw-r--r-- | src/main/java/org/apache/commons/math/random/RandomGenerator.java | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/src/main/java/org/apache/commons/math/random/RandomGenerator.java b/src/main/java/org/apache/commons/math/random/RandomGenerator.java new file mode 100644 index 0000000..0b86c2a --- /dev/null +++ b/src/main/java/org/apache/commons/math/random/RandomGenerator.java @@ -0,0 +1,148 @@ +/* + * 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; + + +/** + * Interface extracted from <code>java.util.Random</code>. This interface is + * implemented by {@link AbstractRandomGenerator}. + * + * @since 1.1 + * @version $Revision: 949750 $ $Date: 2010-05-31 16:06:04 +0200 (lun. 31 mai 2010) $ + */ +public interface RandomGenerator { + + /** + * Sets the seed of the underlying random number generator using an + * <code>int</code> seed. + * <p>Sequences of values generated starting with the same seeds + * should be identical. + * </p> + * @param seed the seed value + */ + void setSeed(int seed); + + /** + * Sets the seed of the underlying random number generator using an + * <code>int</code> array seed. + * <p>Sequences of values generated starting with the same seeds + * should be identical. + * </p> + * @param seed the seed value + */ + void setSeed(int[] seed); + + /** + * Sets the seed of the underlying random number generator using a + * <code>long</code> seed. + * <p>Sequences of values generated starting with the same seeds + * should be identical. + * </p> + * @param seed the seed value + */ + void setSeed(long seed); + + /** + * 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 + */ + void nextBytes(byte[] bytes); + + /** + * 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 + */ + int 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. + */ + int nextInt(int 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 + */ + long nextLong(); + + /** + * 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 + */ + boolean nextBoolean(); + + /** + * 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 + */ + float nextFloat(); + + /** + * 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 + */ + double nextDouble(); + + /** + * 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 + */ + double nextGaussian(); +} |