@Override
public SparseVector toSparseVector(StringVector features) {
SparseVector x = new SparseVector();
int index;
if (bias > 0) x.add(new SparseItem(0, bias));
for (StringItem f : features) {
index = feature_map.index(f.getType(), f.getValue());
if (index > 0) x.add(index, f.getWeight());
}
x.sort();
return x;
}
@Override
public void addFeatures(StringVector features) {
for (StringItem f : features) feature_map.add(f.getType(), f.getValue());
}