ml/feature/JavaStringIndexerSuite.java

0001 /*
0002  * Licensed to the Apache Software Foundation (ASF) under one or more
0003  * contributor license agreements.  See the NOTICE file distributed with
0004  * this work for additional information regarding copyright ownership.
0005  * The ASF licenses this file to You under the Apache License, Version 2.0
0006  * (the "License"); you may not use this file except in compliance with
0007  * the License.  You may obtain a copy of the License at
0008  *
0009  *    http://www.apache.org/licenses/LICENSE-2.0
0010  *
0011  * Unless required by applicable law or agreed to in writing, software
0012  * distributed under the License is distributed on an "AS IS" BASIS,
0013  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
0014  * See the License for the specific language governing permissions and
0015  * limitations under the License.
0016  */
0017
0018 package org.apache.spark.ml.feature;
0019
0020 import java.util.Arrays;
0021 import java.util.List;
0022
0023 import static org.apache.spark.sql.types.DataTypes.*;
0024
0025 import org.junit.Assert;
0026 import org.junit.Test;
0027
0028 import org.apache.spark.SharedSparkSession;
0029 import org.apache.spark.sql.Dataset;
0030 import org.apache.spark.sql.Row;
0031 import org.apache.spark.sql.RowFactory;
0032 import org.apache.spark.sql.types.StructField;
0033 import org.apache.spark.sql.types.StructType;
0034
0035 public class JavaStringIndexerSuite extends SharedSparkSession {
0036
0037   @Test
0038   public void testStringIndexer() {
0039     StructType schema = createStructType(new StructField[]{
0040       createStructField("id", IntegerType, false),
0041       createStructField("label", StringType, false)
0042     });
0043     List<Row> data = Arrays.asList(
0044       cr(0, "a"), cr(1, "b"), cr(2, "c"), cr(3, "a"), cr(4, "a"), cr(5, "c"));
0045     Dataset<Row> dataset = spark.createDataFrame(data, schema);
0046
0047     StringIndexer indexer = new StringIndexer()
0048       .setInputCol("label")
0049       .setOutputCol("labelIndex");
0050     Dataset<Row> output = indexer.fit(dataset).transform(dataset);
0051
0052     Assert.assertEquals(
0053       Arrays.asList(cr(0, 0.0), cr(1, 2.0), cr(2, 1.0), cr(3, 0.0), cr(4, 0.0), cr(5, 1.0)),
0054       output.orderBy("id").select("id", "labelIndex").collectAsList());
0055   }
0056
0057   /**
0058    * An alias for RowFactory.create.
0059    */
0060   private Row cr(Object... values) {
0061     return RowFactory.create(values);
0062   }
0063 }