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author | BenFradet <benjamin.fradet@gmail.com> | 2015-12-08 12:45:34 -0800 |
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committer | Joseph K. Bradley <joseph@databricks.com> | 2015-12-08 12:45:34 -0800 |
commit | 06746b3005e5e9892d0314bee3bfdfaebc36d3d4 (patch) | |
tree | d0bdd5af1a56b07fe00c6c5c44a0da3f276338e6 /examples/src/main/java | |
parent | 5cb4695051e3dac847b1ea14d62e54dcf672c31c (diff) | |
download | spark-06746b3005e5e9892d0314bee3bfdfaebc36d3d4.tar.gz spark-06746b3005e5e9892d0314bee3bfdfaebc36d3d4.tar.bz2 spark-06746b3005e5e9892d0314bee3bfdfaebc36d3d4.zip |
[SPARK-12159][ML] Add user guide section for IndexToString transformer
Documentation regarding the `IndexToString` label transformer with code snippets in Scala/Java/Python.
Author: BenFradet <benjamin.fradet@gmail.com>
Closes #10166 from BenFradet/SPARK-12159.
Diffstat (limited to 'examples/src/main/java')
-rw-r--r-- | examples/src/main/java/org/apache/spark/examples/ml/JavaIndexToStringExample.java | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/examples/src/main/java/org/apache/spark/examples/ml/JavaIndexToStringExample.java b/examples/src/main/java/org/apache/spark/examples/ml/JavaIndexToStringExample.java new file mode 100644 index 0000000000..3ccd699326 --- /dev/null +++ b/examples/src/main/java/org/apache/spark/examples/ml/JavaIndexToStringExample.java @@ -0,0 +1,75 @@ +/* + * 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; + +import org.apache.spark.SparkConf; +import org.apache.spark.api.java.JavaRDD; +import org.apache.spark.api.java.JavaSparkContext; +import org.apache.spark.sql.SQLContext; + +// $example on$ +import java.util.Arrays; + +import org.apache.spark.ml.feature.IndexToString; +import org.apache.spark.ml.feature.StringIndexer; +import org.apache.spark.ml.feature.StringIndexerModel; +import org.apache.spark.sql.DataFrame; +import org.apache.spark.sql.Row; +import org.apache.spark.sql.RowFactory; +import org.apache.spark.sql.types.DataTypes; +import org.apache.spark.sql.types.Metadata; +import org.apache.spark.sql.types.StructField; +import org.apache.spark.sql.types.StructType; +// $example off$ + +public class JavaIndexToStringExample { + public static void main(String[] args) { + SparkConf conf = new SparkConf().setAppName("JavaIndexToStringExample"); + JavaSparkContext jsc = new JavaSparkContext(conf); + SQLContext sqlContext = new SQLContext(jsc); + + // $example on$ + JavaRDD<Row> jrdd = jsc.parallelize(Arrays.asList( + RowFactory.create(0, "a"), + RowFactory.create(1, "b"), + RowFactory.create(2, "c"), + RowFactory.create(3, "a"), + RowFactory.create(4, "a"), + RowFactory.create(5, "c") + )); + StructType schema = new StructType(new StructField[]{ + new StructField("id", DataTypes.IntegerType, false, Metadata.empty()), + new StructField("category", DataTypes.StringType, false, Metadata.empty()) + }); + DataFrame df = sqlContext.createDataFrame(jrdd, schema); + + StringIndexerModel indexer = new StringIndexer() + .setInputCol("category") + .setOutputCol("categoryIndex") + .fit(df); + DataFrame indexed = indexer.transform(df); + + IndexToString converter = new IndexToString() + .setInputCol("categoryIndex") + .setOutputCol("originalCategory"); + DataFrame converted = converter.transform(indexed); + converted.select("id", "originalCategory").show(); + // $example off$ + jsc.stop(); + } +} |