nom.bdezonia.zorbage.algorithm.MatrixSubtraction Maven / Gradle / Ivy

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/*
 * Zorbage: an algebraic data hierarchy for use in numeric processing.
 *
 * Copyright (c) 2016-2021 Barry DeZonia All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 * 
 * Redistributions of source code must retain the above copyright notice, this list
 * of conditions and the following disclaimer.
 * 
 * Redistributions in binary form must reproduce the above copyright notice, this
 * list of conditions and the following disclaimer in the documentation and/or other
 * materials provided with the distribution.
 * 
 * Neither the name of the  nor the names of its contributors may
 * be used to endorse or promote products derived from this software without specific
 * prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL  BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 */
package nom.bdezonia.zorbage.algorithm;

import nom.bdezonia.zorbage.algebra.Addition;
import nom.bdezonia.zorbage.algebra.Algebra;
import nom.bdezonia.zorbage.algebra.MatrixMember;

/**
 * 
 * @author Barry DeZonia
 *
 */
public class MatrixSubtraction {

	// do not instantiate
	
	private MatrixSubtraction() { }
	
	/**
	 * Subtract two matrices. c = a - b
	 * 
	 * @param algebra
	 * @param a
	 * @param b
	 * @param c
	 */
	public static  & Addition,U>
		void compute(T algebra, MatrixMember a, MatrixMember b, MatrixMember c)
	{
		if (a.rows() != b.rows()) throw new IllegalArgumentException("cannot subtract matrices of different shapes");
		if (a.cols() != b.cols()) throw new IllegalArgumentException("cannot subtract matrices of different shapes");
		if (c != a && c != b) {
			c.alloc(a.rows(), a.cols());
		}
		U atmp = algebra.construct();
		U btmp = algebra.construct();
		U tmp = algebra.construct();
		for (long row = 0; row < a.rows(); row++) {
			for (long col = 0; col < a.cols(); col++) {
				a.getV(row, col, atmp);
				b.getV(row, col, btmp);
				algebra.subtract().call(atmp, btmp, tmp);
				c.setV(row, col, tmp);
			}
		}
	}
}