turicreate.random_forest_regression.create

turicreate.random_forest_regression.create(dataset, target, features=None, max_iterations=10, validation_set='auto', verbose=True, random_seed=None, metric='auto', **kwargs)

Create a RandomForestRegression to predict a scalar target variable using one or more features. In addition to standard numeric and categorical types, features can also be extracted automatically from list- or dictionary-type SFrame columns.

Parameters:
dataset : SFrame

A training dataset containing feature columns and a target column. Only numerical typed (int, float) target column is allowed.

target : str

The name of the column in dataset that is the prediction target. This column must have a numeric type.

features : list[str], optional

A list of columns names of features used for training the model. Defaults to None, using all columns.

max_iterations : int, optional

The number of iterations to perform.

max_depth : float, optional

Maximum depth of a tree.

min_loss_reduction : float, optional (non-negative)

Minimum loss reduction required to make a further partition/split a node during the tree learning phase. Larger (more positive) values can help prevent overfitting by avoiding splits that do not sufficiently reduce the loss function.

min_child_weight : float, optional (non-negative)

Controls the minimum weight of each leaf node. Larger values result in more conservative tree learning and help prevent overfitting. Formally, this is minimum sum of instance weights (hessians) in each node. If the tree learning algorithm results in a leaf node with the sum of instance weights less than min_child_weight, tree building will terminate.

row_subsample : float, optional

Subsample the ratio of the training set in each iteration of tree construction. This is called the bagging trick and usually can help prevent overfitting. Setting it to 0.5 means that model randomly collected half of the examples (rows) to grow each tree.

column_subsample : float, optional

Subsample ratio of the columns in each iteration of tree construction. Like row_subsample, this also usually can help prevent overfitting. Setting it to 0.5 means that model randomly collected half of the columns to grow each tree.

validation_set : SFrame, optional

A dataset for monitoring the model’s generalization performance. For each row of the progress table, the chosen metrics are computed for both the provided training dataset and the validation_set. The format of this SFrame must be the same as the training set. By default this argument is set to ‘auto’ and a validation set is automatically sampled and used for progress printing. If validation_set is set to None, then no additional metrics are computed. This is computed once per full iteration. Large differences in model accuracy between the training data and validation data is indicative of overfitting. The default value is ‘auto’.

verbose : boolean, optional

If True, print progress information during training.

random_seed : int, optional

Seeds random operations such as column and row subsampling, such that results are reproducible.

metric : str or list[str], optional

Performance metric(s) that are tracked during training. When specified, the progress table will display the tracked metric(s) on training and validation set. Supported metrics are: {‘rmse’, ‘max_error’}

kwargs : dict, optional

Additional arguments for training the model.

  • model_checkpoint_path : str, default None
    If specified, checkpoint the model training to the given path every n iterations, where n is specified by model_checkpoint_interval. For instance, if model_checkpoint_interval is 5, and model_checkpoint_path is set to /tmp/model_tmp, the checkpoints will be saved into /tmp/model_tmp/model_checkpoint_5, /tmp/model_tmp/model_checkpoint_10, … etc. Training can be resumed by setting resume_from_checkpoint to one of these checkpoints.
  • model_checkpoint_interval : int, default 5
    If model_check_point_path is specified, save the model to the given path every n iterations.
  • resume_from_checkpoint : str, default None
    Continues training from a model checkpoint. The model must take exact the same training data as the checkpointed model.
Returns:
out : RandomForestRegression

A trained random forest model for regression tasks.

References

Examples

Setup the data:

>>> url = 'https://static.turi.com/datasets/xgboost/mushroom.csv'
>>> data = turicreate.SFrame.read_csv(url)
>>> data['label'] = data['label'] == 'p'

Split the data into training and test data:

>>> train, test = data.random_split(0.8)

Create the model:

>>> model = turicreate.random_forest_regression.create(train, target='label')

Make predictions and evaluate the model:

>>> predictions = model.predict(test)
>>> results = model.evaluate(test)