*/
public void plus(ISparseVector sv, float w) {
if(sv instanceof HashSparseVector){
TIntFloatIterator it = ((HashSparseVector) sv).data.iterator();
while(it.hasNext()){
it.advance();
float v = it.value()*w;
data.adjustOrPutValue(it.key(), v,v);
}
}else if(sv instanceof BinarySparseVector){
TIntIterator it = ((BinarySparseVector) sv).data.iterator();