tf.contrib.estimator.boosted_trees_classifier_train_in_memory

tf.contrib.estimator.boosted_trees_classifier_train_in_memory(
    train_input_fn,
    feature_columns,
    model_dir=None,
    n_classes=canned_boosted_trees._HOLD_FOR_MULTI_CLASS_SUPPORT,
    weight_column=None,
    label_vocabulary=None,
    n_trees=100,
    max_depth=6,
    learning_rate=0.1,
    l1_regularization=0.0,
    l2_regularization=0.0,
    tree_complexity=0.0,
    min_node_weight=0.0,
    config=None,
    train_hooks=None,
    center_bias=False
)

Defined in tensorflow/contrib/estimator/python/estimator/boosted_trees.py.

Trains a boosted tree classifier with in memory dataset.

Example:

bucketized_feature_1 = bucketized_column(
  numeric_column('feature_1'), BUCKET_BOUNDARIES_1)
bucketized_feature_2 = bucketized_column(
  numeric_column('feature_2'), BUCKET_BOUNDARIES_2)

def train_input_fn():
  dataset = create-dataset-from-training-data
  # This is tf.data.Dataset of a tuple of feature dict and label.
  #   e.g. Dataset.zip((Dataset.from_tensors({'f1': f1_array, ...}),
  #                     Dataset.from_tensors(label_array)))
  # The returned Dataset shouldn't be batched.
  # If Dataset repeats, only the first repetition would be used for training.
  return dataset

classifier = boosted_trees_classifier_train_in_memory(
    train_input_fn,
    feature_columns=[bucketized_feature_1, bucketized_feature_2],
    n_trees=100,
    ... <some other params>
)

def input_fn_eval():
  ...
  return dataset

metrics = classifier.evaluate(input_fn=input_fn_eval, steps=10)

Args:

  • train_input_fn: the input function returns a dataset containing a single epoch of unbatched features and labels.
  • feature_columns: An iterable containing all the feature columns used by the model. All items in the set should be instances of classes derived from FeatureColumn.
  • model_dir: Directory to save model parameters, graph and etc. This can also be used to load checkpoints from the directory into a estimator to continue training a previously saved model.
  • n_classes: number of label classes. Default is binary classification. Multiclass support is not yet implemented.
  • weight_column: A string or a _NumericColumn created by tf.feature_column.numeric_column defining feature column representing weights. It is used to downweight or boost examples during training. It will be multiplied by the loss of the example. If it is a string, it is used as a key to fetch weight tensor from the features. If it is a _NumericColumn, raw tensor is fetched by key weight_column.key, then weight_column.normalizer_fn is applied on it to get weight tensor.
  • label_vocabulary: A list of strings represents possible label values. If given, labels must be string type and have any value in label_vocabulary. If it is not given, that means labels are already encoded as integer or float within [0, 1] for n_classes=2 and encoded as integer values in {0, 1,..., n_classes-1} for n_classes>2 . Also there will be errors if vocabulary is not provided and labels are string.
  • n_trees: number trees to be created.
  • max_depth: maximum depth of the tree to grow.
  • learning_rate: shrinkage parameter to be used when a tree added to the model.
  • l1_regularization: regularization multiplier applied to the absolute weights of the tree leafs.
  • l2_regularization: regularization multiplier applied to the square weights of the tree leafs.
  • tree_complexity: regularization factor to penalize trees with more leaves.
  • min_node_weight: minimum hessian a node must have for a split to be considered. The value will be compared with sum(leaf_hessian)/ (batch_size * n_batches_per_layer).
  • config: RunConfig object to configure the runtime settings.
  • train_hooks: a list of Hook instances to be passed to estimator.train()
  • center_bias: Whether bias centering needs to occur. Bias centering refers to the first node in the very first tree returning the prediction that is aligned with the original labels distribution. For example, for regression problems, the first node will return the mean of the labels. For binary classification problems, it will return a logit for a prior probability of label 1.

Returns:

a BoostedTreesClassifier instance created with the given arguments and trained with the data loaded up on memory from the input_fn.

Raises:

  • ValueError: when wrong arguments are given or unsupported functionalities are requested.