@Test public void testEmptyRanks() { assertThat(itemRanks(LongLists.EMPTY_LIST).size(), equalTo(0)); }
@Inject public PopularityRankItemScorer(final InteractionStatistics stats) { statistics = stats; long[] items = stats.getKnownItems().toLongArray(); LongArrays.quickSort(items, (l1, l2) -> Integer.compare(stats.getInteractionCount(l2), stats.getInteractionCount(l1))); Long2IntMap ranks = LongUtils.itemRanks(LongArrayList.wrap(items)); SortedKeyIndex keys = SortedKeyIndex.fromCollection(ranks.keySet()); int n = keys.size(); double[] values = new double[n]; for (int i = 0; i < n; i++) { values[i] = 1.0 - ranks.get(keys.getKey(i)) / ((double) n); } rankScores = Long2DoubleSortedArrayMap.wrap(keys, values); }
@Test public void testSingletonRanks() { Long2IntMap ranks = itemRanks(LongLists.singleton(1)); assertThat(ranks.keySet(), contains(1L)); assertThat(ranks, hasEntry(1L, 0)); }
@Test public void testTwoItemRanks() { Long2IntMap ranks = itemRanks(LongArrayList.wrap(new long[]{1,2})); assertThat(ranks.keySet(), containsInAnyOrder(1L, 2L)); assertThat(ranks, hasEntry(1L, 0)); assertThat(ranks, hasEntry(2L, 1)); }
@Test public void testThreeItemRanks() { Long2IntMap ranks = itemRanks(LongArrayList.wrap(new long[]{1,2,3})); assertThat(ranks.keySet(), containsInAnyOrder(1L, 2L, 3L)); assertThat(ranks, hasEntry(1L, 0)); assertThat(ranks, hasEntry(2L, 1)); assertThat(ranks, hasEntry(3L, 2)); }
static ResultList merge(int n, ResultList left, ResultList right, double weight) { Long2IntMap leftRanks = LongUtils.itemRanks(LongUtils.asLongList(left.idList())); Long2IntMap rightRanks = LongUtils.itemRanks(LongUtils.asLongList(right.idList())); int nl = left.size(); int nr = right.size(); LongSet allItems = new LongOpenHashSet(); allItems.addAll(leftRanks.keySet()); allItems.addAll(rightRanks.keySet()); ResultAccumulator accum = ResultAccumulator.create(n); for (LongIterator iter = allItems.iterator(); iter.hasNext();) { long item = iter.nextLong(); int rl = leftRanks.get(item); int rr = rightRanks.get(item); double s1 = rankToScore(rl, nl); double s2 = rankToScore(rr, nr); double score = weight * s1 + (1.0-weight) * s2; accum.add(new RankBlendResult(item, score, rl >= 0 ? left.get(rl) : null, rl, rr >= 0 ? right.get(rr) : null, rl)); } return accum.finish(); }
@Inject public PopularityRankItemScorer(final InteractionStatistics stats) { statistics = stats; long[] items = stats.getKnownItems().toLongArray(); LongArrays.quickSort(items, new AbstractLongComparator() { @Override public int compare(long l1, long l2) { return Integer.compare(stats.getInteractionCount(l2), stats.getInteractionCount(l1)); } }); Long2IntMap ranks = LongUtils.itemRanks(LongArrayList.wrap(items)); SortedKeyIndex keys = SortedKeyIndex.fromCollection(ranks.keySet()); int n = keys.size(); double[] values = new double[n]; for (int i = 0; i < n; i++) { values[i] = 1.0 - ranks.get(keys.getKey(i)) / ((double) n); } rankScores = Long2DoubleSortedArrayMap.wrap(keys, values); }
static ResultList merge(int n, ResultList left, ResultList right, double weight) { Long2IntMap leftRanks = LongUtils.itemRanks(LongUtils.asLongList(left.idList())); Long2IntMap rightRanks = LongUtils.itemRanks(LongUtils.asLongList(right.idList())); int nl = left.size(); int nr = right.size(); LongSet allItems = new LongOpenHashSet(); allItems.addAll(leftRanks.keySet()); allItems.addAll(rightRanks.keySet()); ResultAccumulator accum = ResultAccumulator.create(n); for (LongIterator iter = allItems.iterator(); iter.hasNext();) { long item = iter.nextLong(); int rl = leftRanks.get(item); int rr = rightRanks.get(item); double s1 = rankToScore(rl, nl); double s2 = rankToScore(rr, nr); double score = weight * s1 + (1.0-weight) * s2; accum.add(new RankBlendResult(item, score, rl >= 0 ? left.get(rl) : null, rl, rr >= 0 ? right.get(rr) : null, rl)); } return accum.finish(); }