/** {@inheritDoc} */
@Override
public RealMatrix multiply(final RealMatrix m) throws IllegalArgumentException {
try {
return multiply((OpenMapRealMatrix) m);
} catch (ClassCastException cce) {
// safety check
MatrixUtils.checkMultiplicationCompatible(this, m);
final int outCols = m.getColumnDimension();
final BlockRealMatrix out = new BlockRealMatrix(rowDimension, outCols);
for (OpenIntToDoubleHashMap.Iterator iterator = entries.iterator(); iterator.hasNext(); ) {
iterator.advance();
final double value = iterator.value();
final int key = iterator.key();
final int i = key / columnDimension;
final int k = key % columnDimension;
for (int j = 0; j < outCols; ++j) {
out.addToEntry(i, j, value * m.getEntry(k, j));
}
}
return out;
}
}
/**
* Returns the result of postmultiplying this by m.
*
* @param m matrix to postmultiply by
* @return this * m
* @throws IllegalArgumentException if columnDimension(this) != rowDimension(m)
*/
public OpenMapRealMatrix multiply(OpenMapRealMatrix m) throws IllegalArgumentException {
// safety check
MatrixUtils.checkMultiplicationCompatible(this, m);
final int outCols = m.getColumnDimension();
OpenMapRealMatrix out = new OpenMapRealMatrix(rowDimension, outCols);
for (OpenIntToDoubleHashMap.Iterator iterator = entries.iterator(); iterator.hasNext(); ) {
iterator.advance();
final double value = iterator.value();
final int key = iterator.key();
final int i = key / columnDimension;
final int k = key % columnDimension;
for (int j = 0; j < outCols; ++j) {
final int rightKey = m.computeKey(k, j);
if (m.entries.containsKey(rightKey)) {
final int outKey = out.computeKey(i, j);
final double outValue = out.entries.get(outKey) + value * m.entries.get(rightKey);
if (outValue == 0.0) {
out.entries.remove(outKey);
} else {
out.entries.put(outKey, outValue);
}
}
}
}
return out;
}
/**
* Compute this minus <code>m</code>.
*
* @param m matrix to be subtracted
* @return this - m
* @throws IllegalArgumentException if m is not the same size as this
*/
public OpenMapRealMatrix subtract(OpenMapRealMatrix m) throws IllegalArgumentException {
// safety check
MatrixUtils.checkAdditionCompatible(this, m);
final OpenMapRealMatrix out = new OpenMapRealMatrix(this);
for (OpenIntToDoubleHashMap.Iterator iterator = m.entries.iterator(); iterator.hasNext(); ) {
iterator.advance();
final int row = iterator.key() / columnDimension;
final int col = iterator.key() - row * columnDimension;
out.setEntry(row, col, getEntry(row, col) - iterator.value());
}
return out;
}
