/**
* Creates a matrix to process genre data and generate the first factor of the proximity matrix
* needed for a {@code HIRItemScorer}.
*
* @param dao The DataAccessObject interfacing with the item data for the model
* @param gDao The genreDataAccessObject interfacing with the genre data for the model
*/
public RowStochasticFactorOfProximity(ItemDAO dao, ItemGenreDAO gDao) {
LongSet items = dao.getItemIds();
int genreSize = gDao.getGenreSize();
itemSize = items.size();
double[][] data = new double[itemSize][genreSize];
rowStochastic = MatrixUtils.createRealMatrix(data);
int i = 0;
LongIterator iter = items.iterator();
while (iter.hasNext()) {
long item = iter.nextLong();
rowStochastic.setRowVector(i, gDao.getItemGenre(item));
i++;
}
}
/** Constructs and returns a {@link HIRModel}. */
@Override
public HIRModel get() {
LongSet items = buildContext.getItems();
LongIterator outer = items.iterator();
while (outer.hasNext()) {
final long item1 = outer.nextLong();
final SparseVector vec1 = buildContext.itemVector(item1);
LongIterator inner = items.iterator();
while (inner.hasNext()) {
final long item2 = inner.nextLong();
SparseVector vec2 = buildContext.itemVector(item2);
DAMatrix.putItemPair(item1, vec1, item2, vec2);
}
}
return new HIRModel(
DAMatrix.buildMatrix(), RSMatrix.RowStochastic(), TFMatrix.ColumnStochastic());
}
private DataSource downsample(DataSource data, LongSet testUsers) throws IOException {
String fileName = getFileName(data);
File output = new File(fileName);
UpToDateChecker checker = new UpToDateChecker();
checker.addInput(data.lastModified());
checker.addOutput(output);
if (!checker.isUpToDate()) {
RandomOrder<Rating> order = new RandomOrder<Rating>();
Random rng = new Random();
// write datasource
CSVWriter csv = null;
try {
csv = CSVWriter.open(output, null);
Cursor<UserHistory<Rating>> histories =
data.getUserEventDAO().streamEventsByUser(Rating.class);
for (UserHistory<Rating> ratings : histories) {
List<Rating> rats = new ArrayList<Rating>(ratings);
order.apply(rats, rng);
for (int i = 0; i < rats.size(); i++) {
if (!testUsers.contains(ratings.getUserId()) || i < retain) {
Rating rating = rats.get(i);
Preference pref = rating.getPreference();
csv.writeRow(
Lists.newArrayList(
rating.getUserId(),
rating.getItemId(),
rating.getValue(),
rating.getTimestamp()));
}
}
}
} finally {
if (csv != null) {
csv.close();
}
}
}
CSVDataSourceBuilder builder = new CSVDataSourceBuilder(data.getName());
builder.setDomain(data.getPreferenceDomain());
builder.setFile(output);
return builder.build();
}
public void close() {
if (readed != null) readed.close();
}
public boolean addReadedId(long id) {
return readed.add(id);
}