eps_sdev.rst

eps_sdev

• Available in: Naïve-Bayes
• Hyperparameter: yes

Description

This option specifies the threshold value for standard deviation. If this threshold is not met, then the min_sdev value is used.

This option is not set by default. When specified, this value must be greater than 0.

Related Parameters

• min_sdev

Example

.. tabs::
   .. code-tab:: r R

        library(h2o)
        h2o.init()

        # import the cars dataset
        cars <- h2o.importFile("https://s3.amazonaws.com/h2o-public-test-data/smalldata/junit/cars_20mpg.csv")

        # Specify model-building exercise (1:binomial, 2:multinomial)
        problem <- sample(1:2, 1)

        # Specify response column based on predictor value and problem type
        predictors <- c("displacement","power","weight","acceleration","year")
        if ( problem == 1 ) { response_col <- "economy_20mpg" } else { response_col <- "cylinders" }

        # Convert the response column to a factor
        cars[, response_col] <- as.factor(cars[, response_col])

        # Specify model parameters
        laplace <- c(1)
        min_sdev <- c(0.1)
        eps_sdev <- c(0.5)

        # Build the model
        cars_naivebayes <- h2o.naiveBayes(x = predictors, y = response_col, training_frame = cars,
                                          eps_sdev = eps_sdev, min_sdev = min_sdev, laplace = laplace)
        print(cars_naivebayes)

        # Specify grid search parameters
        grid_space <- list()
        grid_space$laplace <- c(1, 2)
        grid_space$min_sdev <- c(0.1, 0.2)
        grid_space$eps_sdev <- c(0.5, 0.6)

        # Specify response column based on predictor value and problem type
        predictors <- c("displacement","power","weight","acceleration","year")
        if ( problem == 1 ) { response_col <- "economy_20mpg"} else { response_col <- "cylinders" }

        # Convert the response column to a factor
        cars[, response_col] <- as.factor(cars[, response_col])

        # Construct the grid of naive bayes models
        cars_naivebayes_grid <- h2o.grid("naivebayes", grid_id = "naiveBayes_grid_cars_test",
                                         x = predictors, y = response_col, training_frame = cars,
                                         hyper_params = grid_space)
        print(cars_naivebayes_grid)

   .. code-tab:: python

        import h2o
        h2o.init()
        import random
        from h2o.estimators.naive_bayes import H2ONaiveBayesEstimator
        from h2o.grid.grid_search import H2OGridSearch

        # import the cars dataset:
        cars = h2o.import_file("https://s3.amazonaws.com/h2o-public-test-data/smalldata/junit/cars_20mpg.csv")

        # Specify model-building exercise (1:binomial, 2:multinomial)
        problem = random.sample(["binomial","multinomial"],1)

        # Specify response column based on predictor value and problem type
        predictors = ["displacement","power","weight","acceleration","year"]
        if problem == "binomial":
            response_col = "economy_20mpg"
        else:
            response_col = "cylinders"

        # Convert the response column to a factor
        cars[response_col] = cars[response_col].asfactor()

        # Train the model
        cars_nb = H2ONaiveBayesEstimator(min_sdev=0.1, eps_sdev=0.5, seed=1234)
        cars_nb.train(x=predictors, y=response_col, training_frame=cars)
        cars_nb.show()

        # Predict on training data
        cars_pred = cars_nb.predict(cars)
        cars_pred.head()

        # Specify grid search parameters
        hyper_params = {'laplace':[1,2], 'min_sdev':[0.1,0.2], 'eps_sdev':[0.5,0.6]}

        # Construct the grid of naive bayes models
        cars_nb = H2ONaiveBayesEstimator(seed = 1234)
        cars_grid = H2OGridSearch(model=cars_nb, hyper_params=hyper_params)

        # Train using the grid
        cars_grid.train(x=predictors, y=response_col, training_frame=cars)
        cars_grid.show()