[SPARK-11689][ML] Add user guide and example code for LDA under spark.ml

jira: https://issues.apache.org/jira/browse/SPARK-11689

Add simple user guide for LDA under spark.ml and example code under examples/. Use include_example to include example code in the user guide markdown. Check SPARK-11606 for instructions.

Original PR is reverted due to document build error. https://github.com/apache/spark/pull/9722

mengxr feynmanliang yinxusen  Sorry for the troubling.

Author: Yuhao Yang <hhbyyh@gmail.com>

Closes #9974 from hhbyyh/ldaMLExample.
This commit is contained in:
Yuhao Yang 2015-11-30 14:56:51 -08:00 committed by Xiangrui Meng
parent a8ceec5e8c
commit e232720a65
5 changed files with 208 additions and 1 deletions

31
docs/ml-clustering.md Normal file
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@ -0,0 +1,31 @@
---
layout: global
title: Clustering - ML
displayTitle: <a href="ml-guide.html">ML</a> - Clustering
---
In this section, we introduce the pipeline API for [clustering in mllib](mllib-clustering.html).
## Latent Dirichlet allocation (LDA)
`LDA` is implemented as an `Estimator` that supports both `EMLDAOptimizer` and `OnlineLDAOptimizer`,
and generates a `LDAModel` as the base models. Expert users may cast a `LDAModel` generated by
`EMLDAOptimizer` to a `DistributedLDAModel` if needed.
<div class="codetabs">
<div data-lang="scala" markdown="1">
Refer to the [Scala API docs](api/scala/index.html#org.apache.spark.ml.clustering.LDA) for more details.
{% include_example scala/org/apache/spark/examples/ml/LDAExample.scala %}
</div>
<div data-lang="java" markdown="1">
Refer to the [Java API docs](api/java/org/apache/spark/ml/clustering/LDA.html) for more details.
{% include_example java/org/apache/spark/examples/ml/JavaLDAExample.java %}
</div>
</div>

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@ -40,6 +40,7 @@ Also, some algorithms have additional capabilities in the `spark.ml` API; e.g.,
provide class probabilities, and linear models provide model summaries.
* [Feature extraction, transformation, and selection](ml-features.html)
* [Clustering](ml-clustering.html)
* [Decision Trees for classification and regression](ml-decision-tree.html)
* [Ensembles](ml-ensembles.html)
* [Linear methods with elastic net regularization](ml-linear-methods.html)
@ -950,4 +951,4 @@ model.transform(test)
{% endhighlight %}
</div>
</div>
</div>

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@ -69,6 +69,7 @@ We list major functionality from both below, with links to detailed guides.
concepts. It also contains sections on using algorithms within the Pipelines API, for example:
* [Feature extraction, transformation, and selection](ml-features.html)
* [Clustering](ml-clustering.html)
* [Decision trees for classification and regression](ml-decision-tree.html)
* [Ensembles](ml-ensembles.html)
* [Linear methods with elastic net regularization](ml-linear-methods.html)

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/*
* 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.spark.examples.ml;
// $example on$
import java.util.regex.Pattern;
import org.apache.spark.SparkConf;
import org.apache.spark.api.java.JavaRDD;
import org.apache.spark.api.java.JavaSparkContext;
import org.apache.spark.api.java.function.Function;
import org.apache.spark.ml.clustering.LDA;
import org.apache.spark.ml.clustering.LDAModel;
import org.apache.spark.mllib.linalg.Vector;
import org.apache.spark.mllib.linalg.VectorUDT;
import org.apache.spark.mllib.linalg.Vectors;
import org.apache.spark.sql.DataFrame;
import org.apache.spark.sql.Row;
import org.apache.spark.sql.SQLContext;
import org.apache.spark.sql.catalyst.expressions.GenericRow;
import org.apache.spark.sql.types.Metadata;
import org.apache.spark.sql.types.StructField;
import org.apache.spark.sql.types.StructType;
// $example off$
/**
* An example demonstrating LDA
* Run with
* <pre>
* bin/run-example ml.JavaLDAExample
* </pre>
*/
public class JavaLDAExample {
// $example on$
private static class ParseVector implements Function<String, Row> {
private static final Pattern separator = Pattern.compile(" ");
@Override
public Row call(String line) {
String[] tok = separator.split(line);
double[] point = new double[tok.length];
for (int i = 0; i < tok.length; ++i) {
point[i] = Double.parseDouble(tok[i]);
}
Vector[] points = {Vectors.dense(point)};
return new GenericRow(points);
}
}
public static void main(String[] args) {
String inputFile = "data/mllib/sample_lda_data.txt";
// Parses the arguments
SparkConf conf = new SparkConf().setAppName("JavaLDAExample");
JavaSparkContext jsc = new JavaSparkContext(conf);
SQLContext sqlContext = new SQLContext(jsc);
// Loads data
JavaRDD<Row> points = jsc.textFile(inputFile).map(new ParseVector());
StructField[] fields = {new StructField("features", new VectorUDT(), false, Metadata.empty())};
StructType schema = new StructType(fields);
DataFrame dataset = sqlContext.createDataFrame(points, schema);
// Trains a LDA model
LDA lda = new LDA()
.setK(10)
.setMaxIter(10);
LDAModel model = lda.fit(dataset);
System.out.println(model.logLikelihood(dataset));
System.out.println(model.logPerplexity(dataset));
// Shows the result
DataFrame topics = model.describeTopics(3);
topics.show(false);
model.transform(dataset).show(false);
jsc.stop();
}
// $example off$
}

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@ -0,0 +1,77 @@
/*
* 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.spark.examples.ml
// scalastyle:off println
import org.apache.spark.{SparkContext, SparkConf}
import org.apache.spark.mllib.linalg.{VectorUDT, Vectors}
// $example on$
import org.apache.spark.ml.clustering.LDA
import org.apache.spark.sql.{Row, SQLContext}
import org.apache.spark.sql.types.{StructField, StructType}
// $example off$
/**
* An example demonstrating a LDA of ML pipeline.
* Run with
* {{{
* bin/run-example ml.LDAExample
* }}}
*/
object LDAExample {
final val FEATURES_COL = "features"
def main(args: Array[String]): Unit = {
val input = "data/mllib/sample_lda_data.txt"
// Creates a Spark context and a SQL context
val conf = new SparkConf().setAppName(s"${this.getClass.getSimpleName}")
val sc = new SparkContext(conf)
val sqlContext = new SQLContext(sc)
// $example on$
// Loads data
val rowRDD = sc.textFile(input).filter(_.nonEmpty)
.map(_.split(" ").map(_.toDouble)).map(Vectors.dense).map(Row(_))
val schema = StructType(Array(StructField(FEATURES_COL, new VectorUDT, false)))
val dataset = sqlContext.createDataFrame(rowRDD, schema)
// Trains a LDA model
val lda = new LDA()
.setK(10)
.setMaxIter(10)
.setFeaturesCol(FEATURES_COL)
val model = lda.fit(dataset)
val transformed = model.transform(dataset)
val ll = model.logLikelihood(dataset)
val lp = model.logPerplexity(dataset)
// describeTopics
val topics = model.describeTopics(3)
// Shows the result
topics.show(false)
transformed.show(false)
// $example off$
sc.stop()
}
}
// scalastyle:on println