From 87e13ca8bbb6fdb409aa601d6b74cc400951004e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Christoph=20B=C3=BCscher?= Date: Fri, 8 Jul 2016 15:11:52 +0200 Subject: [PATCH] Add Discounted Cumulative Gain metric --- .../rankeval/DiscountedCumulativeGainAtN.java | 118 ++++++++++++++++++ .../rankeval/RankedListQualityMetric.java | 3 + .../DiscountedCumulativeGainAtNTests.java | 70 +++++++++++ .../rest-api-spec/test/rank_eval/20_dcg.yaml | 105 ++++++++++++++++ 4 files changed, 296 insertions(+) create mode 100644 modules/rank-eval/src/main/java/org/elasticsearch/index/rankeval/DiscountedCumulativeGainAtN.java create mode 100644 modules/rank-eval/src/test/java/org/elasticsearch/index/rankeval/DiscountedCumulativeGainAtNTests.java create mode 100644 modules/rank-eval/src/test/resources/rest-api-spec/test/rank_eval/20_dcg.yaml diff --git a/modules/rank-eval/src/main/java/org/elasticsearch/index/rankeval/DiscountedCumulativeGainAtN.java b/modules/rank-eval/src/main/java/org/elasticsearch/index/rankeval/DiscountedCumulativeGainAtN.java new file mode 100644 index 00000000000..c1bed32952b --- /dev/null +++ b/modules/rank-eval/src/main/java/org/elasticsearch/index/rankeval/DiscountedCumulativeGainAtN.java @@ -0,0 +1,118 @@ +/* + * Licensed to Elasticsearch under one or more contributor + * license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright + * ownership. Elasticsearch licenses this file to you under + * the Apache License, Version 2.0 (the "License"); you may + * not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ + +package org.elasticsearch.index.rankeval; + +import org.elasticsearch.common.ParseField; +import org.elasticsearch.common.ParseFieldMatcherSupplier; +import org.elasticsearch.common.io.stream.StreamInput; +import org.elasticsearch.common.io.stream.StreamOutput; +import org.elasticsearch.common.xcontent.ConstructingObjectParser; +import org.elasticsearch.common.xcontent.XContentParser; +import org.elasticsearch.search.SearchHit; + +import java.io.IOException; +import java.util.ArrayList; +import java.util.Collection; +import java.util.HashMap; +import java.util.List; +import java.util.Map; + +public class DiscountedCumulativeGainAtN extends RankedListQualityMetric { + + /** Number of results to check against a given set of relevant results. */ + private int n; + + public static final String NAME = "dcg_at_n"; + private static final double LOG2 = Math.log(2.0); + + public DiscountedCumulativeGainAtN(StreamInput in) throws IOException { + n = in.readInt(); + } + + @Override + public void writeTo(StreamOutput out) throws IOException { + out.writeInt(n); + } + + @Override + public String getWriteableName() { + return NAME; + } + + /** + * Initialises n with 10 + * */ + public DiscountedCumulativeGainAtN() { + this.n = 10; + } + + /** + * @param n number of top results to check against a given set of relevant results. Must be positive. + */ + public DiscountedCumulativeGainAtN(int n) { + if (n <= 0) { + throw new IllegalArgumentException("number of results to check needs to be positive but was " + n); + } + this.n = n; + } + + /** + * Return number of search results to check for quality. + */ + public int getN() { + return n; + } + + @Override + public EvalQueryQuality evaluate(SearchHit[] hits, List ratedDocs) { + Map ratedDocsById = new HashMap<>(); + for (RatedDocument doc : ratedDocs) { + ratedDocsById.put(doc.getDocID(), doc); + } + + Collection unknownDocIds = new ArrayList(); + double dcg = 0; + + for (int i = 0; (i < n && i < hits.length); i++) { + int rank = i + 1; // rank is 1-based + String id = hits[i].getId(); + RatedDocument ratedDoc = ratedDocsById.get(id); + if (ratedDoc != null) { + int rel = ratedDoc.getRating(); + dcg += (Math.pow(2, rel) - 1) / ((Math.log(rank + 1) / LOG2)); + } else { + unknownDocIds.add(id); + } + } + return new EvalQueryQuality(dcg, unknownDocIds); + } + + private static final ParseField SIZE_FIELD = new ParseField("size"); + private static final ConstructingObjectParser PARSER = + new ConstructingObjectParser<>("dcg_at", a -> new DiscountedCumulativeGainAtN((Integer) a[0])); + + static { + PARSER.declareInt(ConstructingObjectParser.constructorArg(), SIZE_FIELD); + } + + public static DiscountedCumulativeGainAtN fromXContent(XContentParser parser, ParseFieldMatcherSupplier matcher) { + return PARSER.apply(parser, matcher); + } +} diff --git a/modules/rank-eval/src/main/java/org/elasticsearch/index/rankeval/RankedListQualityMetric.java b/modules/rank-eval/src/main/java/org/elasticsearch/index/rankeval/RankedListQualityMetric.java index 1bfd6e516f5..ba28b6f9bb0 100644 --- a/modules/rank-eval/src/main/java/org/elasticsearch/index/rankeval/RankedListQualityMetric.java +++ b/modules/rank-eval/src/main/java/org/elasticsearch/index/rankeval/RankedListQualityMetric.java @@ -63,6 +63,9 @@ public abstract class RankedListQualityMetric implements NamedWriteable { case ReciprocalRank.NAME: rc = ReciprocalRank.fromXContent(parser, context); break; + case DiscountedCumulativeGainAtN.NAME: + rc = DiscountedCumulativeGainAtN.fromXContent(parser, context); + break; default: throw new ParsingException(parser.getTokenLocation(), "[_na] unknown query metric name [{}]", metricName); } diff --git a/modules/rank-eval/src/test/java/org/elasticsearch/index/rankeval/DiscountedCumulativeGainAtNTests.java b/modules/rank-eval/src/test/java/org/elasticsearch/index/rankeval/DiscountedCumulativeGainAtNTests.java new file mode 100644 index 00000000000..2114feaa835 --- /dev/null +++ b/modules/rank-eval/src/test/java/org/elasticsearch/index/rankeval/DiscountedCumulativeGainAtNTests.java @@ -0,0 +1,70 @@ +/* + * Licensed to Elasticsearch under one or more contributor + * license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright + * ownership. Elasticsearch licenses this file to you under + * the Apache License, Version 2.0 (the "License"); you may + * not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ + +package org.elasticsearch.index.rankeval; + +import org.elasticsearch.common.ParseFieldMatcher; +import org.elasticsearch.common.text.Text; +import org.elasticsearch.common.xcontent.XContentFactory; +import org.elasticsearch.common.xcontent.XContentParser; +import org.elasticsearch.search.SearchHit; +import org.elasticsearch.search.internal.InternalSearchHit; +import org.elasticsearch.test.ESTestCase; + +import java.io.IOException; +import java.util.ArrayList; +import java.util.Collections; +import java.util.List; +import java.util.concurrent.ExecutionException; + +public class DiscountedCumulativeGainAtNTests extends ESTestCase { + + /** + * Assuming the docs are ranked in the following order: + * + * rank | rel_rank | 2^(rel_rank) - 1 | log_2(rank + 1) | (2^(rel_rank) - 1) / log_2(rank + 1) + * ------------------------------------------------------------------------------------------- + * 1 | 3 | 7.0 | 1.0 | 7.0 + * 2 | 2 | 3.0 | 1.5849625007211563 | 1.8927892607143721 + * 3 | 3 | 7.0 | 2.0 | 3.5 + * 4 | 0 | 0.0 | 2.321928094887362 | 0.0 + * 5 | 1 | 1.0 | 2.584962500721156 | 0.38685280723454163 + * 6 | 2 | 3.0 | 2.807354922057604 | 1.0686215613240666 + */ + public void testDCGAtSix() throws IOException, InterruptedException, ExecutionException { + List rated = new ArrayList<>(); + int[] relevanceRatings = new int[] { 3, 2, 3, 0, 1, 2 }; + SearchHit[] hits = new InternalSearchHit[6]; + for (int i = 0; i < 6; i++) { + rated.add(new RatedDocument(Integer.toString(i), relevanceRatings[i])); + hits[i] = new InternalSearchHit(i, Integer.toString(i), new Text("type"), Collections.emptyMap()); + } + assertEquals(13.84826362927298d, (new DiscountedCumulativeGainAtN(6)).evaluate(hits, rated).getQualityLevel(), 0.00001); + } + + + public void testParseFromXContent() throws IOException { + String xContent = " {\n" + + " \"size\": 8\n" + + "}"; + XContentParser parser = XContentFactory.xContent(xContent).createParser(xContent); + DiscountedCumulativeGainAtN dcgAt = DiscountedCumulativeGainAtN.fromXContent(parser, () -> ParseFieldMatcher.STRICT); + assertEquals(8, dcgAt.getN()); + } +} diff --git a/modules/rank-eval/src/test/resources/rest-api-spec/test/rank_eval/20_dcg.yaml b/modules/rank-eval/src/test/resources/rest-api-spec/test/rank_eval/20_dcg.yaml new file mode 100644 index 00000000000..6fb28286138 --- /dev/null +++ b/modules/rank-eval/src/test/resources/rest-api-spec/test/rank_eval/20_dcg.yaml @@ -0,0 +1,105 @@ +--- +"Response format": + + - do: + index: + index: foo + type: bar + id: doc1 + body: { "bar": 1 } + + - do: + index: + index: foo + type: bar + id: doc2 + body: { "bar": 2 } + + - do: + index: + index: foo + type: bar + id: doc3 + body: { "bar": 3 } + + - do: + index: + index: foo + type: bar + id: doc4 + body: { "bar": 4 } + - do: + index: + index: foo + type: bar + id: doc5 + body: { "bar": 5 } + - do: + index: + index: foo + type: bar + id: doc6 + body: { "bar": 6 } + + - do: + indices.refresh: {} + + - do: + rank_eval: + body: { + "spec_id" : "dcg_qa_queries", + "requests" : [ + { + "id": "dcg_query", + "request": { "query": { "match_all" : {}}, "sort" : [ "bar" ] }, + "ratings": [{ "doc1": 3}, {"doc2": 2}, {"doc3": 3}, {"doc4": 0}, {"doc5": 1}, {"doc6": 2}] + } + ], + "metric" : { "dcg_at_n": { "size": 6}} + } + + - match: {rank_eval.spec_id: "dcg_qa_queries"} + - match: {rank_eval.quality_level: 13.84826362927298} + +# reverse the order in which the results are returned (less relevant docs first) + + - do: + rank_eval: + body: { + "spec_id" : "dcg_qa_queries", + "requests" : [ + { + "id": "dcg_query_reverse", + "request": { "query": { "match_all" : {}}, "sort" : [ {"bar" : "desc" }] }, + "ratings": [{ "doc1": 3}, {"doc2": 2}, {"doc3": 3}, {"doc4": 0}, {"doc5": 1}, {"doc6": 2}] + }, + ], + "metric" : { "dcg_at_n": { "size": 6}} + } + + - match: {rank_eval.spec_id: "dcg_qa_queries"} + - match: {rank_eval.quality_level: 10.29967439154499} + +# if we mix both, we should get the average + + - do: + rank_eval: + body: { + "spec_id" : "dcg_qa_queries", + "requests" : [ + { + "id": "dcg_query", + "request": { "query": { "match_all" : {}}, "sort" : [ "bar" ] }, + "ratings": [{ "doc1": 3}, {"doc2": 2}, {"doc3": 3}, {"doc4": 0}, {"doc5": 1}, {"doc6": 2}] + }, + { + "id": "dcg_query_reverse", + "request": { "query": { "match_all" : {}}, "sort" : [ {"bar" : "desc" }] }, + "ratings": [{ "doc1": 3}, {"doc2": 2}, {"doc3": 3}, {"doc4": 0}, {"doc5": 1}, {"doc6": 2}] + }, + ], + "metric" : { "dcg_at_n": { "size": 6}} + } + + - match: {rank_eval.spec_id: "dcg_qa_queries"} + - match: {rank_eval.quality_level: 12.073969010408984}