diff options
4 files changed, 50 insertions, 94 deletions
diff --git a/docs/ml-clustering.md b/docs/ml-clustering.md index 1245b8bbc8..876a280c4c 100644 --- a/docs/ml-clustering.md +++ b/docs/ml-clustering.md @@ -79,6 +79,11 @@ Refer to the [Java API docs](api/java/org/apache/spark/ml/clustering/KMeans.html {% include_example java/org/apache/spark/examples/ml/JavaKMeansExample.java %} </div> +<div data-lang="python" markdown="1"> +Refer to the [Python API docs](api/python/pyspark.ml.html#pyspark.ml.clustering.KMeans) for more details. + +{% include_example python/ml/kmeans_example.py %} +</div> </div> diff --git a/examples/src/main/java/org/apache/spark/examples/ml/JavaKMeansExample.java b/examples/src/main/java/org/apache/spark/examples/ml/JavaKMeansExample.java index 65e29ade29..2489a9b80b 100644 --- a/examples/src/main/java/org/apache/spark/examples/ml/JavaKMeansExample.java +++ b/examples/src/main/java/org/apache/spark/examples/ml/JavaKMeansExample.java @@ -17,77 +17,45 @@ package org.apache.spark.examples.ml; -import java.util.regex.Pattern; - -import org.apache.spark.api.java.JavaRDD; -import org.apache.spark.api.java.function.Function; -import org.apache.spark.sql.Dataset; -import org.apache.spark.sql.SparkSession; -import org.apache.spark.sql.catalyst.expressions.GenericRow; // $example on$ import org.apache.spark.ml.clustering.KMeansModel; import org.apache.spark.ml.clustering.KMeans; 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.Dataset; import org.apache.spark.sql.Row; -import org.apache.spark.sql.types.Metadata; -import org.apache.spark.sql.types.StructField; -import org.apache.spark.sql.types.StructType; // $example off$ +import org.apache.spark.sql.SparkSession; /** - * An example demonstrating a k-means clustering. + * An example demonstrating k-means clustering. * Run with * <pre> - * bin/run-example ml.JavaKMeansExample <file> <k> + * bin/run-example ml.JavaKMeansExample * </pre> */ public class JavaKMeansExample { - private static class ParsePoint 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) { - if (args.length != 2) { - System.err.println("Usage: ml.JavaKMeansExample <file> <k>"); - System.exit(1); - } - String inputFile = args[0]; - int k = Integer.parseInt(args[1]); - - // Parses the arguments + // Create a SparkSession. SparkSession spark = SparkSession .builder() .appName("JavaKMeansExample") .getOrCreate(); // $example on$ - // Loads data - JavaRDD<Row> points = spark.read().text(inputFile).javaRDD().map(new ParsePoint()); - StructField[] fields = {new StructField("features", new VectorUDT(), false, Metadata.empty())}; - StructType schema = new StructType(fields); - Dataset<Row> dataset = spark.createDataFrame(points, schema); + // Loads data. + Dataset<Row> dataset = spark.read().format("libsvm").load("data/mllib/sample_kmeans_data.txt"); - // Trains a k-means model - KMeans kmeans = new KMeans() - .setK(k); + // Trains a k-means model. + KMeans kmeans = new KMeans().setK(2).setSeed(1L); KMeansModel model = kmeans.fit(dataset); - // Shows the result + // Evaluate clustering by computing Within Set Sum of Squared Errors. + double WSSSE = model.computeCost(dataset); + System.out.println("Within Set Sum of Squared Errors = " + WSSSE); + + // Shows the result. Vector[] centers = model.clusterCenters(); System.out.println("Cluster Centers: "); for (Vector center: centers) { diff --git a/examples/src/main/python/ml/kmeans_example.py b/examples/src/main/python/ml/kmeans_example.py index 7382396955..4b8b7291f9 100644 --- a/examples/src/main/python/ml/kmeans_example.py +++ b/examples/src/main/python/ml/kmeans_example.py @@ -17,55 +17,45 @@ from __future__ import print_function -import sys +# $example on$ +from pyspark.ml.clustering import KMeans +# $example off$ -import numpy as np -from pyspark.ml.clustering import KMeans, KMeansModel -from pyspark.mllib.linalg import VectorUDT, _convert_to_vector from pyspark.sql import SparkSession -from pyspark.sql.types import Row, StructField, StructType """ -A simple example demonstrating a k-means clustering. +An example demonstrating k-means clustering. Run with: - bin/spark-submit examples/src/main/python/ml/kmeans_example.py <input> <k> + bin/spark-submit examples/src/main/python/ml/kmeans_example.py This example requires NumPy (http://www.numpy.org/). """ -def parseVector(row): - array = np.array([float(x) for x in row.value.split(' ')]) - return _convert_to_vector(array) - - if __name__ == "__main__": - FEATURES_COL = "features" - - if len(sys.argv) != 3: - print("Usage: kmeans_example.py <file> <k>", file=sys.stderr) - exit(-1) - path = sys.argv[1] - k = sys.argv[2] - spark = SparkSession\ .builder\ .appName("PythonKMeansExample")\ .getOrCreate() - lines = spark.read.text(path).rdd - data = lines.map(parseVector) - row_rdd = data.map(lambda x: Row(x)) - schema = StructType([StructField(FEATURES_COL, VectorUDT(), False)]) - df = spark.createDataFrame(row_rdd, schema) + # $example on$ + # Loads data. + dataset = spark.read.format("libsvm").load("data/mllib/sample_kmeans_data.txt") - kmeans = KMeans().setK(2).setSeed(1).setFeaturesCol(FEATURES_COL) - model = kmeans.fit(df) - centers = model.clusterCenters() + # Trains a k-means model. + kmeans = KMeans().setK(2).setSeed(1) + model = kmeans.fit(dataset) + + # Evaluate clustering by computing Within Set Sum of Squared Errors. + wssse = model.computeCost(dataset) + print("Within Set Sum of Squared Errors = " + str(wssse)) + # Shows the result. + centers = model.clusterCenters() print("Cluster Centers: ") for center in centers: print(center) + # $example off$ spark.stop() diff --git a/examples/src/main/scala/org/apache/spark/examples/ml/KMeansExample.scala b/examples/src/main/scala/org/apache/spark/examples/ml/KMeansExample.scala index 2abd588c6f..2341b36db2 100644 --- a/examples/src/main/scala/org/apache/spark/examples/ml/KMeansExample.scala +++ b/examples/src/main/scala/org/apache/spark/examples/ml/KMeansExample.scala @@ -21,12 +21,11 @@ package org.apache.spark.examples.ml // $example on$ import org.apache.spark.ml.clustering.KMeans -import org.apache.spark.mllib.linalg.Vectors -import org.apache.spark.sql.{DataFrame, SparkSession} // $example off$ +import org.apache.spark.sql.SparkSession /** - * An example demonstrating a k-means clustering. + * An example demonstrating k-means clustering. * Run with * {{{ * bin/run-example ml.KMeansExample @@ -35,32 +34,26 @@ import org.apache.spark.sql.{DataFrame, SparkSession} object KMeansExample { def main(args: Array[String]): Unit = { - // Creates a Spark context and a SQL context + // Creates a SparkSession. val spark = SparkSession .builder .appName(s"${this.getClass.getSimpleName}") .getOrCreate() // $example on$ - // Crates a DataFrame - val dataset: DataFrame = spark.createDataFrame(Seq( - (1, Vectors.dense(0.0, 0.0, 0.0)), - (2, Vectors.dense(0.1, 0.1, 0.1)), - (3, Vectors.dense(0.2, 0.2, 0.2)), - (4, Vectors.dense(9.0, 9.0, 9.0)), - (5, Vectors.dense(9.1, 9.1, 9.1)), - (6, Vectors.dense(9.2, 9.2, 9.2)) - )).toDF("id", "features") + // Loads data. + val dataset = spark.read.format("libsvm").load("data/mllib/sample_kmeans_data.txt") - // Trains a k-means model - val kmeans = new KMeans() - .setK(2) - .setFeaturesCol("features") - .setPredictionCol("prediction") + // Trains a k-means model. + val kmeans = new KMeans().setK(2).setSeed(1L) val model = kmeans.fit(dataset) - // Shows the result - println("Final Centers: ") + // Evaluate clustering by computing Within Set Sum of Squared Errors. + val WSSSE = model.computeCost(dataset) + println(s"Within Set Sum of Squared Errors = $WSSSE") + + // Shows the result. + println("Cluster Centers: ") model.clusterCenters.foreach(println) // $example off$ |