/*
 * 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;

/**
 * This class implements a normalized uniform random generator.
 * <p>
 * Since it is a normalized random generator, it generates values from a uniform
 * distribution with mean equal to 0 and standard deviation equal to 1.
 * Generated values fall in the range [-&#x0221A;3, +&#x0221A;3].
 * </p>
 * 
 * @since 1.2
 * 
 * @version $Revision$ $Date$
 */

public class UniformRandomGenerator implements NormalizedRandomGenerator {

	/** Serializable version identifier. */
	private static final long serialVersionUID = 1569292426375546027L;

	/**
	 * Create a new generator.
	 * 
	 * @param generator
	 *            underlying random generator to use
	 */
	public UniformRandomGenerator(RandomGenerator generator) {
		this.generator = generator;
	}

	/**
	 * Generate a random scalar with null mean and unit standard deviation.
	 * <p>
	 * The number generated is uniformly distributed between -&sqrt;(3) and
	 * +&sqrt;(3).
	 * </p>
	 * 
	 * @return a random scalar with null mean and unit standard deviation
	 */
	public double nextNormalizedDouble() {
		return SQRT3 * (2 * generator.nextDouble() - 1.0);
	}

	/** Underlying generator. */
	private RandomGenerator generator;

	/** Square root of three. */
	private static final double SQRT3 = Math.sqrt(3.0);

}
