shared_ptr<mat> filtering(const mat& mrating, mpq& msim){
cout<<"collaborative filtering..."<<endl;
shared_ptr<mat> pm_predict(new mat(mrating));
mat& m_predict = *pm_predict;
int max_row_index = base ? nitem : nuser;
for(mpq_i i=msim.begin(); i!=msim.end(); ++i){
cout<<(i->first+1) * 100 / max_row_index<<"%\r"; cout.flush();
// get current row
row ri(m_predict, i->first);
pq& q = i->second;
// pop all sim rows
for(;!q.empty(); q.pop()){
int index = q.top().first;
double sim = q.top().second;
crow rj(mrating, index);
switch(sim_summing){
case 0:
ri += rj * sim;
break;
case 1:
for(crow::const_iterator j=rj.begin(); j!=rj.end(); ++j){
int col = j.index();
double v = 1 - ( 1 - ri(col) ) * ( 1 - *j * sim );
if(v) ri(col) = v;
}
break;
default:
break;
}
}
}
cout<<endl;
if(vm.count("verbose")) cout<<"prediction matrix:\n"<<m_predict<<endl;
return pm_predict;
}
