@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(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;
}