Merge pull request #11 from mathetake/add-credit-func

Modify relative rank credit function

Author: koiizukag

om/om.go

@@ -58,7 +58,7 @@ func (o *OptimizedMultiLeaving) GetInterleavedRanking(num int, rks ...intergo.Ra
 	return cRks[maxIDx], nil
 }
 
-func getCredit(rankingIdx int, itemId interface{}, idToPlacements []map[interface{}]int, creditLabel int, isSameRankingIdx bool) float64 {
+func (o *OptimizedMultiLeaving) GetCredit(rankingIdx int, itemId interface{}, idToPlacements []map[interface{}]int, creditLabel int, isSameRankingIdx bool) float64 {
 	switch creditLabel {
 	case 0:
 		// credit = 1 / (original rank)
@@ -70,22 +70,19 @@ func getCredit(rankingIdx int, itemId interface{}, idToPlacements []map[interfac
 		}
 	case 1:
 		// credit = -(relative rank - 1)
-		numGreater := 0.0
+		if _, ok := idToPlacements[rankingIdx][itemId]; !ok {
+			return -float64(len(idToPlacements))
+		}
+		var numLess float64
 		for i := 0; i < len(idToPlacements); i++ {
-			_, ok1 := idToPlacements[i][itemId]
-			_, ok2 := idToPlacements[rankingIdx][itemId]
-			if !ok2 {
-				continue
-			}
-			if !ok1 {
-				numGreater += 1
+			if _, ok := idToPlacements[i][itemId]; !ok {
 				continue
 			}
-			if idToPlacements[i][itemId] > idToPlacements[rankingIdx][itemId] {
-				numGreater += 1
+			if idToPlacements[i][itemId] < idToPlacements[rankingIdx][itemId] {
+				numLess += 1
 			}
 		}
-		return -numGreater
+		return -numLess
 	default:
 		// credit = 1 if output ranking idx equals input ranking idx
 		// else credit = 0
@@ -128,7 +125,7 @@ func (o *OptimizedMultiLeaving) CalcInsensitivityAndBias(rks []intergo.Ranking,
 		for j := 0; j < len(res); j++ {
 			var s = 1 / float64(j+1)
 			itemId := rks[res[j].RankingIDx].GetIDByIndex(res[j].ItemIDx)
-			credit := getCredit(i, itemId, idToPlacements, creditLabel, res[j].RankingIDx == i)
+			credit := o.GetCredit(i, itemId, idToPlacements, creditLabel, res[j].RankingIDx == i)
 			ss := s * credit
 			insensitivityMap[i] += ss
 			insensitivityMean += ss

om/om_test.go

@@ -83,6 +83,102 @@ func TestGetInterleavedRanking(t *testing.T) {
 	}
 }
 
+func TestGetCredit(t *testing.T) {
+
+	cases := []struct {
+		rankingIdx       int
+		itemId           interface{}
+		idToPlacements   []map[interface{}]int
+		creditLabel      int
+		isSameRankingIdx bool
+		expected         float64
+	}{
+		{
+			rankingIdx: 1,
+			itemId:     "item1",
+			idToPlacements: []map[interface{}]int{
+				{"item1": 1, "item2": 2, "item3": 3},
+				{"item1": 3, "item2": 1, "item3": 2},
+				{"item1": 2, "item2": 1, "item3": 3},
+			},
+			creditLabel:      0,
+			isSameRankingIdx: false,
+			expected:         0.3333333333333333,
+		},
+		{
+			rankingIdx: 1,
+			itemId:     "item1",
+			idToPlacements: []map[interface{}]int{
+				{"item1": 1, "item2": 2, "item3": 3},
+				{"item1": 3, "item2": 1, "item3": 2},
+				{"item1": 2, "item2": 1, "item3": 3},
+			},
+			creditLabel:      1,
+			isSameRankingIdx: false,
+			expected:         -2.0,
+		},
+		{
+			rankingIdx: 0,
+			itemId:     "item2",
+			idToPlacements: []map[interface{}]int{
+				{"item1": 1, "item3": 3},
+				{"item1": 3, "item2": 1, "item3": 2},
+				{"item1": 2, "item2": 1, "item3": 3},
+			},
+			creditLabel:      1,
+			isSameRankingIdx: false,
+			expected:         -3.0,
+		},
+		{
+			rankingIdx: 1,
+			itemId:     "item2",
+			idToPlacements: []map[interface{}]int{
+				{"item1": 1, "item3": 3},
+				{"item1": 3, "item2": 1, "item3": 2},
+				{"item1": 2, "item2": 1, "item3": 3},
+			},
+			creditLabel:      1,
+			isSameRankingIdx: false,
+			expected:         0.0,
+		},
+		{
+			rankingIdx: 0,
+			itemId:     "item2",
+			idToPlacements: []map[interface{}]int{
+				{"item1": 1, "item2": 2, "item3": 3},
+				{"item1": 3, "item2": 1, "item3": 2},
+				{"item1": 2, "item2": 1, "item3": 3},
+			},
+			creditLabel:      3,
+			isSameRankingIdx: false,
+			expected:         0,
+		},
+		{
+			rankingIdx: 0,
+			itemId:     "item2",
+			idToPlacements: []map[interface{}]int{
+				{"item1": 1, "item2": 2, "item3": 3},
+				{"item1": 3, "item2": 1, "item3": 2},
+				{"item1": 2, "item2": 1, "item3": 3},
+			},
+			creditLabel:      3,
+			isSameRankingIdx: true,
+			expected:         1,
+		},
+	}
+
+	for n, tc := range cases {
+		tcc := tc
+		o := &om.OptimizedMultiLeaving{
+			CreditLabel: tc.creditLabel,
+		}
+		t.Run(fmt.Sprintf("%d-th unit test", n), func(t *testing.T) {
+			actual := o.GetCredit(tcc.rankingIdx, tcc.itemId, tcc.idToPlacements, tcc.creditLabel, tcc.isSameRankingIdx)
+			assert.Equal(t, tcc.expected, actual)
+		})
+	}
+}
+
 func TestPrefixConstraintSampling(t *testing.T) {
 	o := &om.OptimizedMultiLeaving{}