private OpenMapRealMatrix createSparseMatrix(double[][] data) {
OpenMapRealMatrix matrix = new OpenMapRealMatrix(data.length, data[0].length);
for (int row = 0; row < data.length; row++) {
for (int col = 0; col < data[row].length; col++) {
matrix.setEntry(row, col, data[row][col]);
}
}
return matrix;
}
/**
* Optimized method to compute the outer product.
*
* @param v The vector to comput the outer product on
* @return The outer product of <code>this</code> and <code>v</code>
* @throws IllegalArgumentException If the dimensions don't match
*/
public OpenMapRealMatrix outerproduct(OpenMapRealVector v) throws IllegalArgumentException {
checkVectorDimensions(v.getDimension());
OpenMapRealMatrix res = new OpenMapRealMatrix(virtualSize, virtualSize);
Iterator iter = entries.iterator();
while (iter.hasNext()) {
iter.advance();
Iterator iter2 = v.getEntries().iterator();
while (iter2.hasNext()) {
iter2.advance();
res.setEntry(iter.key(), iter2.key(), iter.value() * iter2.value());
}
}
return res;
}
/**
* 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;
}