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Posted to commits@lucene.apache.org by to...@apache.org on 2016/11/19 07:28:53 UTC
lucene-solr:master: LUCENE-7466 - added axiomatic similarity,
patch from Peilin Yang
Repository: lucene-solr
Updated Branches:
refs/heads/master f42cc2a8c -> 4236da27d
LUCENE-7466 - added axiomatic similarity, patch from Peilin Yang
Project: http://git-wip-us.apache.org/repos/asf/lucene-solr/repo
Commit: http://git-wip-us.apache.org/repos/asf/lucene-solr/commit/4236da27
Tree: http://git-wip-us.apache.org/repos/asf/lucene-solr/tree/4236da27
Diff: http://git-wip-us.apache.org/repos/asf/lucene-solr/diff/4236da27
Branch: refs/heads/master
Commit: 4236da27d1b1cbced6c3fed4b3d3094fe796fa7e
Parents: f42cc2a
Author: Tommaso Teofili <to...@apache.org>
Authored: Sat Nov 19 08:28:25 2016 +0100
Committer: Tommaso Teofili <to...@apache.org>
Committed: Sat Nov 19 08:28:25 2016 +0100
----------------------------------------------------------------------
.../lucene/search/similarities/Axiomatic.java | 159 +++++++++++++++++++
.../search/similarities/AxiomaticF1EXP.java | 95 +++++++++++
.../search/similarities/AxiomaticF1LOG.java | 88 ++++++++++
.../search/similarities/AxiomaticF2EXP.java | 94 +++++++++++
.../search/similarities/AxiomaticF2LOG.java | 86 ++++++++++
.../search/similarities/AxiomaticF3EXP.java | 94 +++++++++++
.../search/similarities/AxiomaticF3LOG.java | 83 ++++++++++
.../similarities/TestAxiomaticSimilarity.java | 86 ++++++++++
8 files changed, 785 insertions(+)
----------------------------------------------------------------------
http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/4236da27/lucene/core/src/java/org/apache/lucene/search/similarities/Axiomatic.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/search/similarities/Axiomatic.java b/lucene/core/src/java/org/apache/lucene/search/similarities/Axiomatic.java
new file mode 100644
index 0000000..9c2854c
--- /dev/null
+++ b/lucene/core/src/java/org/apache/lucene/search/similarities/Axiomatic.java
@@ -0,0 +1,159 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF 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.apache.lucene.search.similarities;
+
+
+import java.util.List;
+
+import org.apache.lucene.search.Explanation;
+
+/**
+ * Axiomatic approaches for IR. From Hui Fang and Chengxiang Zhai
+ * 2005. An Exploration of Axiomatic Approaches to Information Retrieval.
+ * In Proceedings of the 28th annual international ACM SIGIR
+ * conference on Research and development in information retrieval
+ * (SIGIR '05). ACM, New York, NY, USA, 480-487.
+ * <p>
+ * There are a family of models. All of them are based on BM25,
+ * Pivoted Document Length Normalization and Language model with
+ * Dirichlet prior. Some components (e.g. Term Frequency,
+ * Inverted Document Frequency) in the original models are modified
+ * so that they follow some axiomatic constraints.
+ * </p>
+ *
+ * @lucene.experimental
+ */
+public abstract class Axiomatic extends SimilarityBase {
+ /**
+ * hyperparam for the growth function
+ */
+ protected final float s;
+
+ /**
+ * hyperparam for the primitive weighthing function
+ */
+ protected final float k;
+
+ /**
+ * the query length
+ */
+ protected final int queryLen;
+
+ /**
+ * Constructor setting all Axiomatic hyperparameters
+ * @param s hyperparam for the growth function
+ * @param queryLen the query length
+ * @param k hyperparam for the primitive weighting function
+ */
+ public Axiomatic(float s, int queryLen, float k) {
+ if (Float.isFinite(s) == false || Float.isNaN(s) || s < 0 || s > 1) {
+ throw new IllegalArgumentException("illegal s value: " + s + ", must be between 0 and 1");
+ }
+ if (Float.isFinite(k) == false || Float.isNaN(k) || k < 0 || k > 1) {
+ throw new IllegalArgumentException("illegal k value: " + k + ", must be between 0 and 1");
+ }
+ if (queryLen < 0 || queryLen > Integer.MAX_VALUE) {
+ throw new IllegalArgumentException("illegal query length value: "
+ + queryLen + ", must be larger 0 and smaller than MAX_INT");
+ }
+ this.s = s;
+ this.queryLen = queryLen;
+ this.k = k;
+ }
+
+ /**
+ * Constructor setting only s, letting k and queryLen to default
+ * @param s hyperparam for the growth function
+ */
+ public Axiomatic(float s) {
+ this(s, 1, 0.35f);
+ }
+
+ /**
+ * Constructor setting s and queryLen, letting k to default
+ * @param s hyperparam for the growth function
+ * @param queryLen the query length
+ */
+ public Axiomatic(float s, int queryLen) {
+ this(s, queryLen, 0.35f);
+ }
+
+ /**
+ * Default constructor
+ */
+ public Axiomatic() {
+ this(0.25f, 1, 0.35f);
+ }
+
+ @Override
+ public float score(BasicStats stats, float freq, float docLen) {
+ return tf(stats, freq, docLen)
+ * ln(stats, freq, docLen)
+ * tfln(stats, freq, docLen)
+ * idf(stats, freq, docLen)
+ - gamma(stats, freq, docLen);
+ }
+
+ @Override
+ protected void explain(List<Explanation> subs, BasicStats stats, int doc,
+ float freq, float docLen) {
+ if (stats.getBoost() != 1.0f) {
+ subs.add(Explanation.match(stats.getBoost(), "boost"));
+ }
+
+ subs.add(Explanation.match(this.k, "k"));
+ subs.add(Explanation.match(this.s, "s"));
+ subs.add(Explanation.match(this.queryLen, "queryLen"));
+ subs.add(Explanation.match(tf(stats, freq, docLen), "tf"));
+ subs.add(Explanation.match(ln(stats, freq, docLen), "ln"));
+ subs.add(Explanation.match(tfln(stats, freq, docLen), "tfln"));
+ subs.add(Explanation.match(idf(stats, freq, docLen), "idf"));
+ subs.add(Explanation.match(gamma(stats, freq, docLen), "gamma"));
+ super.explain(subs, stats, doc, freq, docLen);
+ }
+
+ /**
+ * Name of the axiomatic method.
+ */
+ @Override
+ public abstract String toString();
+
+ /**
+ * compute the term frequency component
+ */
+ protected abstract float tf(BasicStats stats, float freq, float docLen);
+
+ /**
+ * compute the document length component
+ */
+ protected abstract float ln(BasicStats stats, float freq, float docLen);
+
+ /**
+ * compute the mixed term frequency and document length component
+ */
+ protected abstract float tfln(BasicStats stats, float freq, float docLen);
+
+ /**
+ * compute the inverted document frequency component
+ */
+ protected abstract float idf(BasicStats stats, float freq, float docLen);
+
+ /**
+ * compute the gamma component (only for F3EXp and F3LOG)
+ */
+ protected abstract float gamma(BasicStats stats, float freq, float docLen);
+}
\ No newline at end of file
http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/4236da27/lucene/core/src/java/org/apache/lucene/search/similarities/AxiomaticF1EXP.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/search/similarities/AxiomaticF1EXP.java b/lucene/core/src/java/org/apache/lucene/search/similarities/AxiomaticF1EXP.java
new file mode 100644
index 0000000..62317fd
--- /dev/null
+++ b/lucene/core/src/java/org/apache/lucene/search/similarities/AxiomaticF1EXP.java
@@ -0,0 +1,95 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF 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.apache.lucene.search.similarities;
+
+/**
+ * F1EXP is defined as Sum(tf(term_doc_freq)*ln(docLen)*IDF(term))
+ * where IDF(t) = pow((N+1)/df(t), k) N=total num of docs, df=doc freq
+ *
+ * @lucene.experimental
+ */
+public class AxiomaticF1EXP extends Axiomatic {
+ /**
+ * Constructor setting s and k, letting queryLen to default
+ * @param s hyperparam for the growth function
+ * @param k hyperparam for the primitive weighting function
+ */
+ public AxiomaticF1EXP(float s, float k) {
+ super(s, 1, k);
+ }
+
+ /**
+ * Constructor setting s only, letting k and queryLen to default
+ * @param s hyperparam for the growth function
+ */
+ public AxiomaticF1EXP(float s) {
+ this(s, 0.35f);
+ }
+
+ /**
+ * Default constructor
+ */
+ public AxiomaticF1EXP() {
+ super();
+ }
+
+ @Override
+ public String toString() {
+ return "F1EXP";
+ }
+
+ /**
+ * compute the term frequency component
+ */
+ @Override
+ protected float tf(BasicStats stats, float freq, float docLen) {
+ if (freq <= 0.0) return 0f;
+ return (float) (1 + Math.log(1 + Math.log(freq)));
+ }
+
+ /**
+ * compute the document length component
+ */
+ @Override
+ protected float ln(BasicStats stats, float freq, float docLen) {
+ return (stats.getAvgFieldLength() + this.s) / (stats.getAvgFieldLength() + docLen * this.s);
+ }
+
+ /**
+ * compute the mixed term frequency and document length component
+ */
+ @Override
+ protected float tfln(BasicStats stats, float freq, float docLen) {
+ return 1f;
+ }
+
+ /**
+ * compute the inverted document frequency component
+ */
+ @Override
+ protected float idf(BasicStats stats, float freq, float docLen) {
+ return (float) Math.pow((stats.getNumberOfDocuments() + 1.0) / stats.getDocFreq(), this.k);
+ }
+
+ /**
+ * compute the gamma component
+ */
+ @Override
+ protected float gamma(BasicStats stats, float freq, float docLen) {
+ return 0f;
+ }
+}
\ No newline at end of file
http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/4236da27/lucene/core/src/java/org/apache/lucene/search/similarities/AxiomaticF1LOG.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/search/similarities/AxiomaticF1LOG.java b/lucene/core/src/java/org/apache/lucene/search/similarities/AxiomaticF1LOG.java
new file mode 100644
index 0000000..7cce2be
--- /dev/null
+++ b/lucene/core/src/java/org/apache/lucene/search/similarities/AxiomaticF1LOG.java
@@ -0,0 +1,88 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF 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.apache.lucene.search.similarities;
+
+/**
+ * F1LOG is defined as Sum(tf(term_doc_freq)*ln(docLen)*IDF(term))
+ * where IDF(t) = ln((N+1)/df(t)) N=total num of docs, df=doc freq
+ *
+ * @lucene.experimental
+ */
+public class AxiomaticF1LOG extends Axiomatic {
+
+ /**
+ * Constructor setting s only, letting k and queryLen to default
+ *
+ * @param s hyperparam for the growth function
+ */
+ public AxiomaticF1LOG(float s) {
+ super(s);
+ }
+
+ /**
+ * Default constructor
+ */
+ public AxiomaticF1LOG() {
+ super();
+ }
+
+ @Override
+ public String toString() {
+ return "F1LOG";
+ }
+
+ /**
+ * compute the term frequency component
+ */
+ @Override
+ protected float tf(BasicStats stats, float freq, float docLen) {
+ if (freq <= 0.0) return 0f;
+ return (float) (1 + Math.log(1 + Math.log(freq)));
+ }
+
+ /**
+ * compute the document length component
+ */
+ @Override
+ protected float ln(BasicStats stats, float freq, float docLen) {
+ return (stats.getAvgFieldLength() + this.s) / (stats.getAvgFieldLength() + docLen * this.s);
+ }
+
+ /**
+ * compute the mixed term frequency and document length component
+ */
+ @Override
+ protected float tfln(BasicStats stats, float freq, float docLen) {
+ return 1f;
+ }
+
+ /**
+ * compute the inverted document frequency component
+ */
+ @Override
+ protected float idf(BasicStats stats, float freq, float docLen) {
+ return (float) Math.log((stats.getNumberOfDocuments() + 1.0) / stats.getDocFreq());
+ }
+
+ /**
+ * compute the gamma component
+ */
+ @Override
+ protected float gamma(BasicStats stats, float freq, float docLen) {
+ return 0f;
+ }
+}
\ No newline at end of file
http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/4236da27/lucene/core/src/java/org/apache/lucene/search/similarities/AxiomaticF2EXP.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/search/similarities/AxiomaticF2EXP.java b/lucene/core/src/java/org/apache/lucene/search/similarities/AxiomaticF2EXP.java
new file mode 100644
index 0000000..f9bc98a
--- /dev/null
+++ b/lucene/core/src/java/org/apache/lucene/search/similarities/AxiomaticF2EXP.java
@@ -0,0 +1,94 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF 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.apache.lucene.search.similarities;
+
+/**
+ * F2EXP is defined as Sum(tfln(term_doc_freq, docLen)*IDF(term))
+ * where IDF(t) = pow((N+1)/df(t), k) N=total num of docs, df=doc freq
+ *
+ * @lucene.experimental
+ */
+public class AxiomaticF2EXP extends Axiomatic {
+ /**
+ * Constructor setting s and k, letting queryLen to default
+ * @param s hyperparam for the growth function
+ * @param k hyperparam for the primitive weighting function
+ */
+ public AxiomaticF2EXP(float s, float k) {
+ super(s, 1, k);
+ }
+
+ /**
+ * Constructor setting s only, letting k and queryLen to default
+ * @param s hyperparam for the growth function
+ */
+ public AxiomaticF2EXP(float s) {
+ this(s, 0.35f);
+ }
+
+ /**
+ * Default constructor
+ */
+ public AxiomaticF2EXP() {
+ super();
+ }
+
+ @Override
+ public String toString() {
+ return "F2EXP";
+ }
+
+ /**
+ * compute the term frequency component
+ */
+ @Override
+ protected float tf(BasicStats stats, float freq, float docLen) {
+ return 1f;
+ }
+
+ /**
+ * compute the document length component
+ */
+ @Override
+ protected float ln(BasicStats stats, float freq, float docLen) {
+ return 1f;
+ }
+
+ /**
+ * compute the mixed term frequency and document length component
+ */
+ @Override
+ protected float tfln(BasicStats stats, float freq, float docLen) {
+ return freq / (freq + this.s + this.s * docLen / stats.getAvgFieldLength());
+ }
+
+ /**
+ * compute the inverted document frequency component
+ */
+ @Override
+ protected float idf(BasicStats stats, float freq, float docLen) {
+ return (float) Math.pow((stats.getNumberOfDocuments() + 1.0) / stats.getDocFreq(), this.k);
+ }
+
+ /**
+ * compute the gamma component
+ */
+ @Override
+ protected float gamma(BasicStats stats, float freq, float docLen) {
+ return 0f;
+ }
+}
\ No newline at end of file
http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/4236da27/lucene/core/src/java/org/apache/lucene/search/similarities/AxiomaticF2LOG.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/search/similarities/AxiomaticF2LOG.java b/lucene/core/src/java/org/apache/lucene/search/similarities/AxiomaticF2LOG.java
new file mode 100644
index 0000000..fee2000
--- /dev/null
+++ b/lucene/core/src/java/org/apache/lucene/search/similarities/AxiomaticF2LOG.java
@@ -0,0 +1,86 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF 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.apache.lucene.search.similarities;
+
+/**
+ * F2EXP is defined as Sum(tfln(term_doc_freq, docLen)*IDF(term))
+ * where IDF(t) = ln((N+1)/df(t)) N=total num of docs, df=doc freq
+ *
+ * @lucene.experimental
+ */
+public class AxiomaticF2LOG extends Axiomatic {
+ /**
+ * Constructor setting s only, letting k and queryLen to default
+ *
+ * @param s hyperparam for the growth function
+ */
+ public AxiomaticF2LOG(float s) {
+ super(s);
+ }
+
+ /**
+ * Default constructor
+ */
+ public AxiomaticF2LOG() {
+ super();
+ }
+
+ @Override
+ public String toString() {
+ return "F2LOG";
+ }
+
+ /**
+ * compute the term frequency component
+ */
+ @Override
+ protected float tf(BasicStats stats, float freq, float docLen) {
+ return 1f;
+ }
+
+ /**
+ * compute the document length component
+ */
+ @Override
+ protected float ln(BasicStats stats, float freq, float docLen) {
+ return 1f;
+ }
+
+ /**
+ * compute the mixed term frequency and document length component
+ */
+ @Override
+ protected float tfln(BasicStats stats, float freq, float docLen) {
+ return freq / (freq + this.s + this.s * docLen / stats.getAvgFieldLength());
+ }
+
+ /**
+ * compute the inverted document frequency component
+ */
+ @Override
+ protected float idf(BasicStats stats, float freq, float docLen) {
+ return (float) Math.log((stats.getNumberOfDocuments() + 1.0) / stats.getDocFreq());
+ }
+
+ /**
+ * compute the gamma component
+ */
+ @Override
+ protected float gamma(BasicStats stats, float freq, float docLen) {
+ return 0f;
+ }
+}
\ No newline at end of file
http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/4236da27/lucene/core/src/java/org/apache/lucene/search/similarities/AxiomaticF3EXP.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/search/similarities/AxiomaticF3EXP.java b/lucene/core/src/java/org/apache/lucene/search/similarities/AxiomaticF3EXP.java
new file mode 100644
index 0000000..c20194a
--- /dev/null
+++ b/lucene/core/src/java/org/apache/lucene/search/similarities/AxiomaticF3EXP.java
@@ -0,0 +1,94 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF 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.apache.lucene.search.similarities;
+
+/**
+ * F2EXP is defined as Sum(tf(term_doc_freq)*IDF(term)-gamma(docLen, queryLen))
+ * where IDF(t) = pow((N+1)/df(t), k) N=total num of docs, df=doc freq
+ * gamma(docLen, queryLen) = (docLen-queryLen)*queryLen*s/avdl
+ *
+ * @lucene.experimental
+ */
+public class AxiomaticF3EXP extends Axiomatic {
+
+ /**
+ * Constructor setting all Axiomatic hyperparameters
+ *
+ * @param s hyperparam for the growth function
+ * @param queryLen the query length
+ * @param k hyperparam for the primitive weighting function
+ */
+ public AxiomaticF3EXP(float s, int queryLen, float k) {
+ super(s, queryLen, k);
+ }
+
+ /**
+ * Constructor setting s and queryLen, letting k to default
+ *
+ * @param s hyperparam for the growth function
+ * @param queryLen the query length
+ */
+ public AxiomaticF3EXP(float s, int queryLen) {
+ this(s, queryLen, 0.35f);
+ }
+
+ @Override
+ public String toString() {
+ return "F3EXP";
+ }
+
+ /**
+ * compute the term frequency component
+ */
+ @Override
+ protected float tf(BasicStats stats, float freq, float docLen) {
+ if (freq <= 0.0) return 0f;
+ return (float) (1 + Math.log(1 + Math.log(freq)));
+ }
+
+ /**
+ * compute the document length component
+ */
+ @Override
+ protected float ln(BasicStats stats, float freq, float docLen) {
+ return 1f;
+ }
+
+ /**
+ * compute the mixed term frequency and document length component
+ */
+ @Override
+ protected float tfln(BasicStats stats, float freq, float docLen) {
+ return 1f;
+ }
+
+ /**
+ * compute the inverted document frequency component
+ */
+ @Override
+ protected float idf(BasicStats stats, float freq, float docLen) {
+ return (float) Math.pow((stats.getNumberOfDocuments() + 1.0) / stats.getDocFreq(), this.k);
+ }
+
+ /**
+ * compute the gamma component
+ */
+ @Override
+ protected float gamma(BasicStats stats, float freq, float docLen) {
+ return (docLen - this.queryLen) * this.s * this.queryLen / stats.getAvgFieldLength();
+ }
+}
\ No newline at end of file
http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/4236da27/lucene/core/src/java/org/apache/lucene/search/similarities/AxiomaticF3LOG.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/java/org/apache/lucene/search/similarities/AxiomaticF3LOG.java b/lucene/core/src/java/org/apache/lucene/search/similarities/AxiomaticF3LOG.java
new file mode 100644
index 0000000..a9d82ad
--- /dev/null
+++ b/lucene/core/src/java/org/apache/lucene/search/similarities/AxiomaticF3LOG.java
@@ -0,0 +1,83 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF 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.apache.lucene.search.similarities;
+
+/**
+ * F2EXP is defined as Sum(tf(term_doc_freq)*IDF(term)-gamma(docLen, queryLen))
+ * where IDF(t) = ln((N+1)/df(t)) N=total num of docs, df=doc freq
+ * gamma(docLen, queryLen) = (docLen-queryLen)*queryLen*s/avdl
+ *
+ * @lucene.experimental
+ */
+public class AxiomaticF3LOG extends Axiomatic {
+
+ /**
+ * Constructor setting s and queryLen, letting k to default
+ *
+ * @param s hyperparam for the growth function
+ * @param queryLen the query length
+ */
+ public AxiomaticF3LOG(float s, int queryLen) {
+ super(s, queryLen);
+ }
+
+ @Override
+ public String toString() {
+ return "F3LOG";
+ }
+
+ /**
+ * compute the term frequency component
+ */
+ @Override
+ protected float tf(BasicStats stats, float freq, float docLen) {
+ if (freq <= 0.0) return 0f;
+ return (float) (1 + Math.log(1 + Math.log(freq)));
+ }
+
+ /**
+ * compute the document length component
+ */
+ @Override
+ protected float ln(BasicStats stats, float freq, float docLen) {
+ return 1f;
+ }
+
+ /**
+ * compute the mixed term frequency and document length component
+ */
+ @Override
+ protected float tfln(BasicStats stats, float freq, float docLen) {
+ return 1f;
+ }
+
+ /**
+ * compute the inverted document frequency component
+ */
+ @Override
+ protected float idf(BasicStats stats, float freq, float docLen) {
+ return (float) Math.log((stats.getNumberOfDocuments() + 1.0) / stats.getDocFreq());
+ }
+
+ /**
+ * compute the gamma component
+ */
+ @Override
+ protected float gamma(BasicStats stats, float freq, float docLen) {
+ return (docLen - this.queryLen) * this.s * this.queryLen / stats.getAvgFieldLength();
+ }
+}
\ No newline at end of file
http://git-wip-us.apache.org/repos/asf/lucene-solr/blob/4236da27/lucene/core/src/test/org/apache/lucene/search/similarities/TestAxiomaticSimilarity.java
----------------------------------------------------------------------
diff --git a/lucene/core/src/test/org/apache/lucene/search/similarities/TestAxiomaticSimilarity.java b/lucene/core/src/test/org/apache/lucene/search/similarities/TestAxiomaticSimilarity.java
new file mode 100644
index 0000000..44c7e1d
--- /dev/null
+++ b/lucene/core/src/test/org/apache/lucene/search/similarities/TestAxiomaticSimilarity.java
@@ -0,0 +1,86 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF 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.apache.lucene.search.similarities;
+
+import org.apache.lucene.util.LuceneTestCase;
+
+public class TestAxiomaticSimilarity extends LuceneTestCase {
+
+ public void testSaneNormValues() {
+ Axiomatic sim = new AxiomaticF2EXP();
+ for (int i = 0; i < 256; i++) {
+ float len = sim.decodeNormValue((byte) i);
+ assertFalse("negative len: " + len + ", byte=" + i, len < 0.0f);
+ assertFalse("inf len: " + len + ", byte=" + i, Float.isInfinite(len));
+ assertFalse("nan len for byte=" + i, Float.isNaN(len));
+ if (i > 0) {
+ assertTrue("len is not decreasing: " + len + ",byte=" + i, len < sim.decodeNormValue((byte) (i - 1)));
+ }
+ }
+ }
+
+ public void testIllegalS() {
+ IllegalArgumentException expected = expectThrows(IllegalArgumentException.class, () -> {
+ new AxiomaticF2EXP(Float.POSITIVE_INFINITY, 0.1f);
+ });
+ assertTrue(expected.getMessage().contains("illegal s value"));
+
+ expected = expectThrows(IllegalArgumentException.class, () -> {
+ new AxiomaticF2EXP(-1, 0.1f);
+ });
+ assertTrue(expected.getMessage().contains("illegal s value"));
+
+ expected = expectThrows(IllegalArgumentException.class, () -> {
+ new AxiomaticF2EXP(Float.NaN, 0.1f);
+ });
+ assertTrue(expected.getMessage().contains("illegal s value"));
+ }
+
+ public void testIllegalK() {
+ IllegalArgumentException expected = expectThrows(IllegalArgumentException.class, () -> {
+ new AxiomaticF2EXP(0.35f, 2f);
+ });
+ assertTrue(expected.getMessage().contains("illegal k value"));
+
+ expected = expectThrows(IllegalArgumentException.class, () -> {
+ new AxiomaticF2EXP(0.35f, -1f);
+ });
+ assertTrue(expected.getMessage().contains("illegal k value"));
+
+ expected = expectThrows(IllegalArgumentException.class, () -> {
+ new AxiomaticF2EXP(0.35f, Float.POSITIVE_INFINITY);
+ });
+ assertTrue(expected.getMessage().contains("illegal k value"));
+
+ expected = expectThrows(IllegalArgumentException.class, () -> {
+ new AxiomaticF2EXP(0.35f, Float.NaN);
+ });
+ assertTrue(expected.getMessage().contains("illegal k value"));
+ }
+
+ public void testIllegalQL() {
+ IllegalArgumentException expected = expectThrows(IllegalArgumentException.class, () -> {
+ new AxiomaticF3EXP(0.35f, -1);
+ });
+ assertTrue(expected.getMessage().contains("illegal query length value"));
+
+ expected = expectThrows(IllegalArgumentException.class, () -> {
+ new AxiomaticF2EXP(0.35f, Integer.MAX_VALUE + 1);
+ });
+ assertTrue(expected.getMessage().contains("illegal k value"));
+ }
+}