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jBasics is a collection of useful utility classes for Java. This includes helper for XML, mathematic functions, restful web services helper, pattern oriented programming interfaces and more. Currently Java7 and up is supported. Version 1.0 will required at leaset Java8.

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/*
 * Copyright (c) 2009-2015
 * 	IT-Consulting Stephan Schloepke (http://www.schloepke.de/)
 * 	klemm software consulting Mirko Klemm (http://www.klemm-scs.com/)
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package org.jbasics.math.impl;

import org.jbasics.checker.ContractCheck;
import org.jbasics.math.AlgorithmStrategy;
import org.jbasics.math.IrationalNumber;
import org.jbasics.math.strategies.SquareRootAlgorithmStrategy;

import java.math.BigDecimal;

/**
 * Calculates the square root for the given number.  Using the Heron algorithm in conjunction with a start value
 * calculated by the {@link Math#sqrt(double)} function. 
 *
 * @author Stephan Schloepke
 */
public class SquareRootIrationalNumber extends BigDecimalIrationalNumber {
	public static final AlgorithmStrategy STRATEGY = new SquareRootAlgorithmStrategy();
	public static final IrationalNumber SQUARE_ROOT_OF_PI2 = new BigDecimalIrationalNumber(new BigDecimalAlgorithmStrategyChain(
			PiIrationalNumber.STRATEGY, SquareRootIrationalNumber.STRATEGY), MathImplConstants.TWO);
	/**
	 * The constant square root of two.
	 */
	public static final IrationalNumber SQUARE_ROOT_OF_2 = new SquareRootIrationalNumber(MathImplConstants.TWO);
	public static final IrationalNumber SQUARE_ROOT_OF_3 = new SquareRootIrationalNumber(MathImplConstants.THREE);

	private SquareRootIrationalNumber(final BigDecimal x) {
		super(SquareRootIrationalNumber.STRATEGY, x);
	}

	public static IrationalNumber valueOf(final BigDecimal x) {
		if (ContractCheck.mustNotBeNull(x, "x").signum() < 0) {
			throw new ArithmeticException("Square root can only be calculated of a positiv number " + x);
		}
		if (MathImplConstants.TWO.equals(x)) {
			return SquareRootIrationalNumber.SQUARE_ROOT_OF_2;
		} else if (MathImplConstants.HALF.equals(x)) {
			return SquareRootReciprocalIrationalNumber.SQUARE_ROOT_RECIPROCAL_OF_2;
		}
		return new SquareRootIrationalNumber(x);
	}
}