Train AutoML Model in Sparkling Water
-------------------------------------

Sparkling Water provides API in Scala and Python for H2O AutoML.
The following sections describe how to train an AutoML model in Sparkling Water in both languages. See also :ref:`parameters_H2OAutoML`.

.. content-tabs::

    .. tab-container:: Scala
        :title: Scala

        First, let's start Sparkling Shell as

        .. code:: shell

            ./bin/sparkling-shell

        Start H2O cluster inside the Spark environment

        .. code:: scala

            import ai.h2o.sparkling._
            import java.net.URI
            val hc = H2OContext.getOrCreate()

        Parse the data using H2O and convert them to Spark Frame

        .. code:: scala

	        import org.apache.spark.SparkFiles
            spark.sparkContext.addFile("https://raw.githubusercontent.com/h2oai/sparkling-water/master/examples/smalldata/prostate/prostate.csv")
	        val rawSparkDF = spark.read.option("header", "true").option("inferSchema", "true").csv(SparkFiles.get("prostate.csv"))
            val sparkDF = rawSparkDF.withColumn("CAPSULE", $"CAPSULE" cast "string")
            val Array(trainingDF, testingDF) = sparkDF.randomSplit(Array(0.8, 0.2))

        Create an H2OAutoML instance and configure it according to your use case via provided setters. If feature columns are not specified explicitly,
        all columns excluding label, fold, weight, and ignored columns are considered as features.

        .. code:: scala

            import ai.h2o.sparkling.ml.algos.H2OAutoML
            val automl = new H2OAutoML()
            automl.setLabelCol("CAPSULE")
            automl.setIgnoredCols(Array("ID"))

        By default, the ``H2OAutoML`` algorithm distinguishes between a classification and regression problem based on the type of
        the label column of the training dataset. If the label column is a string column, a classification model will be trained.
        If the label column is a numeric column, a regression model will be trained. If you don't want to be worried about
        column data types, you can explicitly identify the problem by using ``ai.h2o.sparkling.ml.algos.classification.H2OAutoMLClassifier``
        or ``ai.h2o.sparkling.ml.algos.regression.H2OAutoMLRegressor`` instead.

        By default, AutoML goes through a huge space of H2O algorithms and their hyper-parameters which requires some time. If you wish to speed up
        the training phase, you can exclude some H2O algorithms and limit the number of trained models.

        .. code:: scala

            automl.setExcludeAlgos(Array("GLM"))
            automl.setMaxModels(10)

        Train the AutoML model. The training phase returns the best model according to the sortMetric. If it's not specified, the sortMetric is chosen automatically.

        .. code:: scala

            automl.setSortMetric("AUC")
            val model = automl.fit(trainingDF)

        You can also get raw model details by calling the ``getModelDetails()`` method available on the model as:

        .. code:: scala

            model.getModelDetails()

        Run Predictions

        .. code:: scala

            model.transform(testingDF).show(false)

        If you are curious to see information about other models created during the AutoML training process, you can get
        a model leaderboard represented by Spark DataFrame.

        .. code:: scala

            val leaderboard = automl.getLeaderboard()
            leaderboard.show(false)

        By default, the leaderboard contains the model name (*model_id*) and various performance metrics like AUC, RMSE, etc.
        If you want to see more information about models, you can add extra columns to the leaderboard by passing column names
        to the ``getLeaderboard()`` method.

        .. code:: scala

            val leaderboard = automl.getLeaderboard("training_time_ms", "predict_time_per_row_ms")
            leaderboard.show(false)

        Extra columns don't have to be specified explicitly. You can specify the addition of all possible extra columns as:

        .. code:: scala

            val leaderboard = automl.getLeaderboard("ALL")
            leaderboard.show(false)

        All models from the leaderboard can be accessed and used for scoring:

        .. code:: scala

            val models = automl.getAllModels()
            models.foreach(_.transform(testingDF).show(false))


    .. tab-container:: Python
        :title: Python

        First, let's start PySparkling Shell as

        .. code:: shell

            ./bin/pysparkling

        Start H2O cluster inside the Spark environment

        .. code:: python

            from pysparkling import *
            hc = H2OContext.getOrCreate()

        Parse the data using H2O and convert them to Spark Frame

        .. code:: python

            import h2o
            frame = h2o.import_file("https://raw.githubusercontent.com/h2oai/sparkling-water/master/examples/smalldata/prostate/prostate.csv")
            sparkDF = hc.asSparkFrame(frame)
            sparkDF = sparkDF.withColumn("CAPSULE", sparkDF.CAPSULE.cast("string"))
            [trainingDF, testingDF] = sparkDF.randomSplit([0.8, 0.2])

        Create an H2OAutoML instance and configure it according to your use case via provided setters or named constructor parameters.
        If feature columns are not specified explicitly, all columns excluding label, fold, weight, and ignored columns are considered as features.

        .. code:: python

            from pysparkling.ml import H2OAutoML
            automl = H2OAutoML(labelCol="CAPSULE", ignoredCols=["ID"])

        By default, the ``H2OAutoML`` algorithm distinguishes between a classification and regression problem based on the type of
        the label column of the training dataset. If the label column is a string column, a classification model will be trained.
        If the label column is a numeric column, a regression model will be trained. If you don't want be worried about
        column data types, you can explicitly identify the problem by using ``H2OAutoMLClassifier`` or ``H2OAutoMLRegressor`` instead.

        By default, AutoML goes through a huge space of H2O algorithms and their hyper-parameters which requires some time. If you wish to speed up
        the training phase, you can exclude some H2O algorithms and limit the number of trained models.

        .. code:: python

            automl.setExcludeAlgos(["GLM"])
            automl.setMaxModels(10)

        Train the AutoML model. The training phase returns the best model according to the sortMetric. If it's not specified, the sortMetric is chosen automatically.

        .. code:: python

            automl.setSortMetric("AUC")
            model = automl.fit(trainingDF)

        You can also get raw model details by calling the ``getModelDetails()`` method available on the model as:

        .. code:: python

            model.getModelDetails()

        Run Predictions

        .. code:: python

            model.transform(testingDF).show(truncate = False)

        If you are curious to see information about other models created during the AutoML training process, you can get
        a model leaderboard represented by Spark DataFrame.

        .. code:: python

            leaderboard = automl.getLeaderboard()
            leaderboard.show(truncate = False)

        By default, the leaderboard contains the model name (*model_id*) and various performance metrics like AUC, RMSE, etc.
        If you want to see more information about models, you can add extra columns to the leaderboard by passing column names
        to the ``getLeaderboard()`` method.

        .. code:: python

            leaderboard = automl.getLeaderboard("training_time_ms", "predict_time_per_row_ms")
            leaderboard.show(truncate = False)

        Extra columns don't have to be specified explicitly. You can specify the addition of all possible extra columns as:

        .. code:: python

            leaderboard = automl.getLeaderboard("ALL")
            leaderboard.show(truncate = False)

        All models from the leaderboard can be accessed and used for scoring:

        .. code:: python

            models = automl.getAllModels()
            for model in models:
                model.transform(testingDF).show(truncate = False)