ChainedApproximation.java

/*
 * 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.approximation;

import org.jbasics.checker.ContractCheck;
import org.jbasics.types.tuples.Range;

import java.math.BigDecimal;
import java.math.MathContext;

public class ChainedApproximation implements Approximation {
	private final Approximation[] chain;

	public ChainedApproximation(final Approximation... chain) {
		this.chain = ContractCheck.mustNotBeNullOrEmpty(chain, "chain"); //$NON-NLS-1$
	}

	@Override
	public ApproximatedResult approximate(final MathContext mc, final BigDecimal c, final Range<BigDecimal> range) {
		ApproximatedResult result = null;
		for (final Approximation a : this.chain) {
			if (result == null) {
				result = a.approximate(mc, c, range);
			} else if (result.getApproximationRange() != null) {
				result = a.approximate(mc, c, result.getApproximationRange());
			} else {
				final BigDecimal temp = result.getApproximatedValue();
				result = a.approximate(mc, c, Range.create(temp, true, temp.add(temp.ulp()), true));
			}
		}
		return result;
	}
}