/*
 * Zorbage: an algebraic data hierarchy for use in numeric processing.
 *
 * Copyright (C) 2016-2018 Barry DeZonia
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. 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.
 * 
 * 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 THE COPYRIGHT HOLDERS OR CONTRIBUTORS 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.type.algebra.Addition;
import nom.bdezonia.zorbage.type.algebra.Group;
import nom.bdezonia.zorbage.type.algebra.MatrixMember;

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

	private MatrixSubtraction() { }
	
	public static <T extends Group<T,U> & Addition<U>,U>
		void compute(T group, MatrixMember<U> a, MatrixMember<U> b, MatrixMember<U> c)
	{
		if (a.rows() != b.rows()) throw new IllegalArgumentException("cannot add matrices of different shapes");
		if (a.cols() != b.cols()) throw new IllegalArgumentException("cannot add matrices of different shapes");
		if (c != a && c != b) {
			c.alloc(a.rows(), a.cols());
		}
		U atmp = group.construct();
		U btmp = group.construct();
		U tmp = group.construct();
		for (long row = 0; row < a.rows(); row++) {
			for (long col = 0; col < a.cols(); col++) {
				a.v(row, col, atmp);
				b.v(row, col, btmp);
				group.subtract(atmp, btmp, tmp);
				c.setV(row, col, tmp);
			}
		}
	}
}

@@ -1930,35 +1930,40 @@
 ception(%22cannot 
-add
+subtract
  matrices of dif
@@ -2054,11 +2054,16 @@
 not 
-add
+subtract
  mat

Fix a couple error messages