# tf.contrib.learn.DNNClassifier

### class tf.contrib.learn.DNNClassifier

See the guide: Learn (contrib) > Estimators

A classifier for TensorFlow DNN models.

Example:

sparse_feature_a = sparse_column_with_hash_bucket(...)
sparse_feature_b = sparse_column_with_hash_bucket(...)

sparse_feature_a_emb = embedding_column(sparse_id_column=sparse_feature_a,
...)
sparse_feature_b_emb = embedding_column(sparse_id_column=sparse_feature_b,
...)

estimator = DNNClassifier(
feature_columns=[sparse_feature_a_emb, sparse_feature_b_emb],
hidden_units=[1024, 512, 256])

# regularization.
estimator = DNNClassifier(
feature_columns=[sparse_feature_a_emb, sparse_feature_b_emb],
hidden_units=[1024, 512, 256],
learning_rate=0.1,
l1_regularization_strength=0.001
))

# Input builders
def input_fn_train: # returns x, y (where y represents label's class index).
pass
estimator.fit(input_fn=input_fn_train)

def input_fn_eval: # returns x, y (where y represents label's class index).
pass
estimator.evaluate(input_fn=input_fn_eval)
estimator.predict(x=x) # returns predicted labels (i.e. label's class index).


Input of fit and evaluate should have following features, otherwise there will be a KeyError:

• if weight_column_name is not None, a feature with key=weight_column_name whose value is a Tensor.
• for each column in feature_columns:
• if column is a SparseColumn, a feature with key=column.name whose value is a SparseTensor.
• if column is a WeightedSparseColumn, two features: the first with key the id column name, the second with key the weight column name. Both features' value must be a SparseTensor.
• if column is a RealValuedColumn, a feature with key=column.name whose value is a Tensor.

## Properties

### bias_

DEPRECATED FUNCTION

THIS FUNCTION IS DEPRECATED. It will be removed after 2016-10-30. Instructions for updating: This method will be removed after the deprecation date. To inspect variables, use get_variable_names() and get_variable_value().

### weights_

DEPRECATED FUNCTION

THIS FUNCTION IS DEPRECATED. It will be removed after 2016-10-30. Instructions for updating: This method will be removed after the deprecation date. To inspect variables, use get_variable_names() and get_variable_value().

## Methods

### __init__(hidden_units, feature_columns, model_dir=None, n_classes=2, weight_column_name=None, optimizer=None, activation_fn=tf.nn.relu, dropout=None, gradient_clip_norm=None, enable_centered_bias=False, config=None, feature_engineering_fn=None, embedding_lr_multipliers=None, input_layer_min_slice_size=None)

Initializes a DNNClassifier instance.

#### Args:

• hidden_units: List of hidden units per layer. All layers are fully connected. Ex. [64, 32] means first layer has 64 nodes and second one has 32.
• 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. It must be greater than 1. Note: Class labels are integers representing the class index (i.e. values from 0 to n_classes-1). For arbitrary label values (e.g. string labels), convert to class indices first.
• weight_column_name: A string defining feature column name representing weights. It is used to down weight or boost examples during training. It will be multiplied by the loss of the example.
• optimizer: An instance of tf.Optimizer used to train the model. If None, will use an Adagrad optimizer.
• activation_fn: Activation function applied to each layer. If None, will use tf.nn.relu.
• dropout: When not None, the probability we will drop out a given coordinate.
• gradient_clip_norm: A float > 0. If provided, gradients are clipped to their global norm with this clipping ratio. See tf.clip_by_global_norm for more details.
• enable_centered_bias: A bool. If True, estimator will learn a centered bias variable for each class. Rest of the model structure learns the residual after centered bias.
• config: RunConfig object to configure the runtime settings.
• feature_engineering_fn: Feature engineering function. Takes features and labels which are the output of input_fn and returns features and labels which will be fed into the model.
• embedding_lr_multipliers: Optional. A dictionary from EmbeddingColumn to a float multiplier. Multiplier will be used to multiply with learning rate for the embedding variables.
• input_layer_min_slice_size: Optional. The min slice size of input layer partitions. If not provided, will use the default of 64M.

#### Returns:

A DNNClassifier estimator.

#### Raises:

• ValueError: If n_classes < 2.

### evaluate(*args, **kwargs)

See Evaluable. (deprecated arguments)

SOME ARGUMENTS ARE DEPRECATED. They will be removed after 2016-12-01. Instructions for updating: Estimator is decoupled from Scikit Learn interface by moving into separate class SKCompat. Arguments x, y and batch_size are only available in the SKCompat class, Estimator will only accept input_fn. Example conversion: est = Estimator(...) -> est = SKCompat(Estimator(...))

#### Raises:

• ValueError: If at least one of x or y is provided, and at least one of input_fn or feed_fn is provided. Or if metrics is not None or dict.

### export(export_dir, input_fn=None, input_feature_key=None, use_deprecated_input_fn=True, signature_fn=None, default_batch_size=1, exports_to_keep=None)

See BaseEstimator.export.

### export_savedmodel(*args, **kwargs)

Exports inference graph as a SavedModel into given dir. (experimental)

THIS FUNCTION IS EXPERIMENTAL. It may change or be removed at any time, and without warning.

#### Args:

• export_dir_base: A string containing a directory to write the exported graph and checkpoints.
• input_fn: A function that takes no argument and returns an InputFnOps.
• default_output_alternative_key: the name of the head to serve when none is specified.
• assets_extra: A dict specifying how to populate the assets.extra directory within the exported SavedModel. Each key should give the destination path (including the filename) relative to the assets.extra directory. The corresponding value gives the full path of the source file to be copied. For example, the simple case of copying a single file without renaming it is specified as {'my_asset_file.txt': '/path/to/my_asset_file.txt'}.
• as_text: whether to write the SavedModel proto in text format.
• exports_to_keep: Number of exports to keep.

#### Returns:

The string path to the exported directory.

#### Raises:

• ValueError: if an unrecognized export_type is requested.

### fit(*args, **kwargs)

See Trainable. (deprecated arguments)

SOME ARGUMENTS ARE DEPRECATED. They will be removed after 2016-12-01. Instructions for updating: Estimator is decoupled from Scikit Learn interface by moving into separate class SKCompat. Arguments x, y and batch_size are only available in the SKCompat class, Estimator will only accept input_fn. Example conversion: est = Estimator(...) -> est = SKCompat(Estimator(...))

#### Raises:

• ValueError: If x or y are not None while input_fn is not None.
• ValueError: If both steps and max_steps are not None.

### get_params(deep=True)

Get parameters for this estimator.

#### Args:

• deep: boolean, optional

If True, will return the parameters for this estimator and contained subobjects that are estimators.

#### Returns:

params : mapping of string to any Parameter names mapped to their values.

### get_variable_names()

Returns list of all variable names in this model.

List of names.

### get_variable_value(name)

Returns value of the variable given by name.

#### Args:

• name: string, name of the tensor.

#### Returns:

Numpy array - value of the tensor.

### partial_fit(*args, **kwargs)

Incremental fit on a batch of samples. (deprecated arguments)

SOME ARGUMENTS ARE DEPRECATED. They will be removed after 2016-12-01. Instructions for updating: Estimator is decoupled from Scikit Learn interface by moving into separate class SKCompat. Arguments x, y and batch_size are only available in the SKCompat class, Estimator will only accept input_fn. Example conversion: est = Estimator(...) -> est = SKCompat(Estimator(...))

This method is expected to be called several times consecutively on different or the same chunks of the dataset. This either can implement iterative training or out-of-core/online training.

This is especially useful when the whole dataset is too big to fit in memory at the same time. Or when model is taking long time to converge, and you want to split up training into subparts.

#### Args:

• x: Matrix of shape [n_samples, n_features...]. Can be iterator that returns arrays of features. The training input samples for fitting the model. If set, input_fn must be None.
• y: Vector or matrix [n_samples] or [n_samples, n_outputs]. Can be iterator that returns array of labels. The training label values (class labels in classification, real numbers in regression). If set, input_fn must be None.
• input_fn: Input function. If set, x, y, and batch_size must be None.
• steps: Number of steps for which to train model. If None, train forever.
• batch_size: minibatch size to use on the input, defaults to first dimension of x. Must be None if input_fn is provided.
• monitors: List of BaseMonitor subclass instances. Used for callbacks inside the training loop.

#### Returns:

self, for chaining.

#### Raises:

• ValueError: If at least one of x and y is provided, and input_fn is provided.

### predict(*args, **kwargs)

Returns predicted classes for given features. (deprecated arguments)

SOME ARGUMENTS ARE DEPRECATED. They will be removed after 2016-09-15. Instructions for updating: The default behavior of predict() is changing. The default value for as_iterable will change to True, and then the flag will be removed altogether. The behavior of this flag is described below.

#### Args:

• x: features.
• input_fn: Input function. If set, x must be None.
• batch_size: Override default batch size.
• as_iterable: If True, return an iterable which keeps yielding predictions for each example until inputs are exhausted. Note: The inputs must terminate if you want the iterable to terminate (e.g. be sure to pass num_epochs=1 if you are using something like read_batch_features).

#### Returns:

Numpy array of predicted classes with shape [batch_size] (or an iterable of predicted classes if as_iterable is True). Each predicted class is represented by its class index (i.e. integer from 0 to n_classes-1).

### predict_classes(*args, **kwargs)

Returns predicted classes for given features. (deprecated arguments)

SOME ARGUMENTS ARE DEPRECATED. They will be removed after 2016-09-15. Instructions for updating: The default behavior of predict() is changing. The default value for as_iterable will change to True, and then the flag will be removed altogether. The behavior of this flag is described below.

#### Args:

• x: features.
• input_fn: Input function. If set, x must be None.
• batch_size: Override default batch size.
• as_iterable: If True, return an iterable which keeps yielding predictions for each example until inputs are exhausted. Note: The inputs must terminate if you want the iterable to terminate (e.g. be sure to pass num_epochs=1 if you are using something like read_batch_features).

#### Returns:

Numpy array of predicted classes with shape [batch_size] (or an iterable of predicted classes if as_iterable is True). Each predicted class is represented by its class index (i.e. integer from 0 to n_classes-1).

### predict_proba(*args, **kwargs)

Returns prediction probabilities for given features. (deprecated arguments)

SOME ARGUMENTS ARE DEPRECATED. They will be removed after 2016-09-15. Instructions for updating: The default behavior of predict() is changing. The default value for as_iterable will change to True, and then the flag will be removed altogether. The behavior of this flag is described below.

#### Args:

• x: features.
• input_fn: Input function. If set, x and y must be None.
• batch_size: Override default batch size.
• as_iterable: If True, return an iterable which keeps yielding predictions for each example until inputs are exhausted. Note: The inputs must terminate if you want the iterable to terminate (e.g. be sure to pass num_epochs=1 if you are using something like read_batch_features).

#### Returns:

Numpy array of predicted probabilities with shape [batch_size, n_classes] (or an iterable of predicted probabilities if as_iterable is True).

### set_params(**params)

Set the parameters of this estimator.

The method works on simple estimators as well as on nested objects (such as pipelines). The former have parameters of the form <component>__<parameter> so that it's possible to update each component of a nested object.

#### Args:

**params: Parameters.

self

#### Raises:

• ValueError: If params contain invalid names.