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H2O AutoML Examples in Python and Scala [Code Snippets]

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H2O AutoML Examples in Python and Scala [Code Snippets]

If you want to automate your machine learning workflow, look no further than H2O AutoML. It trains and tunes models, uses performance-based stopping criteria, and more.

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AutoML is included in H2O versions 3.14.0.1 and above. You can learn more about AutoML here.

H2O AutoML can be used to automate a large portion of the machine learning workflow, which includes automatic training and tuning of many models within a user-specified time limit. The user can also use performance metric-based stopping criteria for the AutoML process rather than a specific time constraint. Stacked ensembles will be automatically trained on the collection's individual models to produce a highly predictive ensemble model which, in most cases, will be the top performing model in the AutoML Leaderboard.

Here is the full working Python code, taken from here:

import h2o
from h2o.automl import H2OAutoML

h2o.init()
df = h2o.import_file("https://raw.githubusercontent.com/h2oai/sparkling-water/master/examples/smalldata/prostate.csv")
train, test = df.split_frame(ratios=[.9])
# Identify predictors and response
x = train.columns
y = "CAPSULE"
x.remove(y)

# For binary classification, response should be a factor
train[y] = train[y].asfactor()
test[y] = test[y].asfactor()

# Run AutoML for 60 seconds
aml = H2OAutoML(max_runtime_secs = 60)
aml.train(x = x, y = y, training_frame = train, leaderboard_frame = test)

# View the AutoML Leaderboard
aml.leaderboard
aml.leader

# To generate predictions on a test set, use `"H2OAutoML"` object, or on the leader model object directly as below:
preds = aml.predict(test)
# or
preds = aml.leader.predict(test)

Here is the full working Scala code:

import ai.h2o.automl.AutoML;
import ai.h2o.automl.AutoMLBuildSpec
import org.apache.spark.h2o._
val h2oContext = H2OContext.getOrCreate(sc)
import h2oContext._
import java.io.File
import h2oContext.implicits._
import water.Key
val prostateData = new H2OFrame(new File("/Users/avkashchauhan/src/github.com/h2oai/sparkling-water/examples/smalldata/prostate.csv"))
val autoMLBuildSpec = new AutoMLBuildSpec()
autoMLBuildSpec.input_spec.training_frame = prostateData
autoMLBuildSpec.input_spec.response_column = "CAPSULE";
autoMLBuildSpec.build_control.loss = "AUTO"
autoMLBuildSpec.build_control.stopping_criteria.set_max_runtime_secs(5)
import java.util.Date;
val aml = AutoML.makeAutoML(Key.make(), new Date(), autoMLBuildSpec)
AutoML.startAutoML(aml)
// Note: In some cases the above call is non-blocking
// So using the following alternative function will block the next commmand, untill the exection of action command
AutoML.startAutoML(autoMLBuildSpec).get()  ## This is forced blocking call
aml.leader
aml.leaderboard

If you want to see the full code execution, see here.

That's it. Enjoy!

TrueSight is an AIOps platform, powered by machine learning and analytics, that elevates IT operations to address multi-cloud complexity and the speed of digital transformation.

Topics:
h2o ,machine learning ,scala ,python ,ai ,automation

Published at DZone with permission of Avkash Chauhan, DZone MVB. See the original article here.

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