/*
* Copyright 2011-2014, by Vladimir Kostyukov and Contributors.
*
* This file is part of la4j project (http://la4j.org)
*
* Licensed 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.
*
* Contributor(s): -
*
*/
package org.la4j.operation.ooplace;
import org.la4j.iterator.MatrixIterator;
import org.la4j.Matrix;
import org.la4j.matrix.DenseMatrix;
import org.la4j.operation.SimpleMatrixMatrixOperation;
import org.la4j.matrix.ColumnMajorSparseMatrix;
import org.la4j.matrix.RowMajorSparseMatrix;
import org.la4j.matrix.SparseMatrix;
public class OoPlaceMatricesSubtraction extends SimpleMatrixMatrixOperation<Matrix> {
@Override
public Matrix apply(DenseMatrix a, DenseMatrix b) {
Matrix result = a.blank();
for (int i = 0; i < a.rows(); i++) {
for (int j = 0; j < a.columns(); j++) {
result.set(i, j, a.get(i, j) - b.get(i, j));
}
}
return result;
}
@Override
public Matrix applySimple(DenseMatrix a, SparseMatrix b) {
Matrix result = a.copy();
MatrixIterator it = b.nonZeroIterator();
while (it.hasNext()) {
double x = it.next();
int i = it.rowIndex();
int j = it.columnIndex();
result.set(i, j, result.get(i, j) - x);
}
return result;
}
@Override
public Matrix applySimple(SparseMatrix a, DenseMatrix b) {
Matrix result = b.multiply(-1.0);
MatrixIterator it = a.nonZeroIterator();
while (it.hasNext()) {
double x = it.next();
int i = it.rowIndex();
int j = it.columnIndex();
result.set(i, j, result.get(i, j) + x);
}
return result;
}
@Override
public Matrix applySimple(SparseMatrix a, SparseMatrix b) {
Matrix result = a.blank();
MatrixIterator these = a.nonZeroIterator();
MatrixIterator those = b.nonZeroIterator();
MatrixIterator both = these.orElseSubtract(those);
while (both.hasNext()) {
double x = both.next();
int i = both.rowIndex();
int j = both.columnIndex();
result.set(i, j, x);
}
return result;
}
@Override
public Matrix apply(RowMajorSparseMatrix a, ColumnMajorSparseMatrix b) {
Matrix result = a.blank();
MatrixIterator these = a.nonZeroRowMajorIterator();
MatrixIterator those = b.nonZeroRowMajorIterator();
MatrixIterator both = these.orElseSubtract(those);
while (both.hasNext()) {
double x = both.next();
int i = both.rowIndex();
int j = both.columnIndex();
result.set(i, j, x);
}
return result;
}
@Override
public Matrix apply(ColumnMajorSparseMatrix a, RowMajorSparseMatrix b) {
Matrix result = a.blank();
MatrixIterator these = a.nonZeroColumnMajorIterator();
MatrixIterator those = b.nonZeroColumnMajorIterator();
MatrixIterator both = these.orElseSubtract(those);
while (both.hasNext()) {
double x = both.next();
int i = both.rowIndex();
int j = both.columnIndex();
result.set(i, j, x);
}
return result;
}
@Override
public void ensureApplicableTo(Matrix a, Matrix b) {
if (a.rows() != b.rows() || a.columns() != b.columns()) {
throw new IllegalArgumentException(
"Given matrices should have the same shape: " +
a.rows() + "x" + a.columns() + " does not equal to " +
b.rows() + "x" + b.columns() + "."
);
}
}
}