diff --git a/examples/src/main/python/mllib/dataset_example.py b/examples/src/main/python/ml/dataframe_example.py similarity index 53% rename from examples/src/main/python/mllib/dataset_example.py rename to examples/src/main/python/ml/dataframe_example.py index e23ecc0c5d302..d2644ca335654 100644 --- a/examples/src/main/python/mllib/dataset_example.py +++ b/examples/src/main/python/ml/dataframe_example.py @@ -16,8 +16,8 @@ # """ -An example of how to use DataFrame as a dataset for ML. Run with:: - bin/spark-submit examples/src/main/python/mllib/dataset_example.py +An example of how to use DataFrame for ML. Run with:: + bin/spark-submit examples/src/main/python/ml/dataframe_example.py """ from __future__ import print_function @@ -28,36 +28,48 @@ from pyspark import SparkContext from pyspark.sql import SQLContext -from pyspark.mllib.util import MLUtils from pyspark.mllib.stat import Statistics - -def summarize(dataset): - print("schema: %s" % dataset.schema().json()) - labels = dataset.map(lambda r: r.label) - print("label average: %f" % labels.mean()) - features = dataset.map(lambda r: r.features) - summary = Statistics.colStats(features) - print("features average: %r" % summary.mean()) - if __name__ == "__main__": if len(sys.argv) > 2: - print("Usage: dataset_example.py ", file=sys.stderr) + print("Usage: dataframe_example.py ", file=sys.stderr) exit(-1) - sc = SparkContext(appName="DatasetExample") + sc = SparkContext(appName="DataFrameExample") sqlContext = SQLContext(sc) if len(sys.argv) == 2: input = sys.argv[1] else: input = "data/mllib/sample_libsvm_data.txt" - points = MLUtils.loadLibSVMFile(sc, input) - dataset0 = sqlContext.inferSchema(points).setName("dataset0").cache() - summarize(dataset0) + + # Load input data + print("Loading LIBSVM file with UDT from " + input + ".") + df = sqlContext.read.format("libsvm").load(input).cache() + print("Schema from LIBSVM:") + df.printSchema() + print("Loaded training data as a DataFrame with " + + str(df.count()) + " records.") + + # Show statistical summary of labels. + labelSummary = df.describe("label") + labelSummary.show() + + # Convert features column to an RDD of vectors. + features = df.select("features").map(lambda r: r.features) + summary = Statistics.colStats(features) + print("Selected features column with average values:\n" + + str(summary.mean())) + + # Save the records in a parquet file. tempdir = tempfile.NamedTemporaryFile(delete=False).name os.unlink(tempdir) - print("Save dataset as a Parquet file to %s." % tempdir) - dataset0.saveAsParquetFile(tempdir) - print("Load it back and summarize it again.") - dataset1 = sqlContext.parquetFile(tempdir).setName("dataset1").cache() - summarize(dataset1) + print("Saving to " + tempdir + " as Parquet file.") + df.write.parquet(tempdir) + + # Load the records back. + print("Loading Parquet file with UDT from " + tempdir) + newDF = sqlContext.read.parquet(tempdir) + print("Schema from Parquet:") + newDF.printSchema() shutil.rmtree(tempdir) + + sc.stop() diff --git a/examples/src/main/scala/org/apache/spark/examples/ml/DataFrameExample.scala b/examples/src/main/scala/org/apache/spark/examples/ml/DataFrameExample.scala index 424f00158c2f2..0a477abae5679 100644 --- a/examples/src/main/scala/org/apache/spark/examples/ml/DataFrameExample.scala +++ b/examples/src/main/scala/org/apache/spark/examples/ml/DataFrameExample.scala @@ -44,10 +44,10 @@ object DataFrameExample { def main(args: Array[String]) { val defaultParams = Params() - val parser = new OptionParser[Params]("DatasetExample") { - head("Dataset: an example app using DataFrame as a Dataset for ML.") + val parser = new OptionParser[Params]("DataFrameExample") { + head("DataFrameExample: an example app using DataFrame for ML.") opt[String]("input") - .text(s"input path to dataset") + .text(s"input path to dataframe") .action((x, c) => c.copy(input = x)) checkConfig { params => success @@ -88,7 +88,7 @@ object DataFrameExample { // Save the records in a parquet file. val tmpDir = Files.createTempDir() tmpDir.deleteOnExit() - val outputDir = new File(tmpDir, "dataset").toString + val outputDir = new File(tmpDir, "dataframe").toString println(s"Saving to $outputDir as Parquet file.") df.write.parquet(outputDir)