tf.contrib.learn.Estimator

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Estimator class is the basic TensorFlow model trainer/evaluator.

Inherits From: BaseEstimator

tf.contrib.learn.Estimator(
    model_fn=None, model_dir=None, config=None, params=None,
    feature_engineering_fn=None
)

THIS CLASS IS DEPRECATED. See contrib/learn/README.md for general migration instructions.

model_fn Model function. Follows the signature:

  • Args:
  • features: single Tensor or dict of Tensors (depending on data passed to fit),
  • labels: Tensor or dict of Tensors (for multi-head models). If mode is ModeKeys.INFER, labels=None will be passed. If the model_fn's signature does not accept mode, the model_fn must still be able to handle labels=None.
  • mode: Optional. Specifies if this training, evaluation or prediction. See ModeKeys.
  • params: Optional dict of hyperparameters. Will receive what is passed to Estimator in params parameter. This allows to configure Estimators from hyper parameter tuning.
  • config: Optional configuration object. Will receive what is passed to Estimator in config parameter, or the default config. Allows updating things in your model_fn based on configuration such as num_ps_replicas.

  • model_dir: Optional directory where model parameters, graph etc are saved. Will receive what is passed to Estimator in model_dir parameter, or the default model_dir. Allows updating things in your model_fn that expect model_dir, such as training hooks.

  • Returns: ModelFnOps

Also supports a legacy signature which returns tuple of:

  • predictions: Tensor, SparseTensor or dictionary of same. Can also be any type that is convertible to a Tensor or SparseTensor, or dictionary of same.
  • loss: Scalar loss Tensor.
  • train_op: Training update Tensor or Operation.

Supports next three signatures for the function:

  • (features, labels) -> (predictions, loss, train_op)
  • (features, labels, mode) -> (predictions, loss, train_op)
  • (features, labels, mode, params) -> (predictions, loss, train_op)
  • (features, labels, mode, params, config) -> (predictions, loss, train_op)
  • (features, labels, mode, params, config, model_dir) -> (predictions, loss, train_op)
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.
config Configuration object.
params dict of hyper parameters that will be passed into model_fn. Keys are names of parameters, values are basic python types.
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 model_fn. Please check model_fn for a definition of features and labels.

ValueError parameters of model_fn don't match params.

config

model_dir Returns a path in which the eval process will look for checkpoints.
model_fn Returns the model_fn which is bound to self.params.

Methods

evaluate

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evaluate(
    x=None, y=None, input_fn=None, feed_fn=None, batch_size=None, steps=None,
    metrics=None, name=None, checkpoint_path=None, hooks=None, log_progress=True
)

See Evaluable. (deprecated arguments)

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

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export(
    export_dir, input_fn=export._default_input_fn, input_feature_key=None,
    use_deprecated_input_fn=True, signature_fn=None, prediction_key=None,
    default_batch_size=1, exports_to_keep=None, checkpoint_path=None
)

Exports inference graph into given dir. (deprecated)

Args
export_dir A string containing a directory to write the exported graph and checkpoints.
input_fn If use_deprecated_input_fn is true, then a function that given Tensor of Example strings, parses it into features that are then passed to the model. Otherwise, a function that takes no argument and returns a tuple of (features, labels), where features is a dict of string key to Tensor and labels is a Tensor that's currently not used (and so can be None).
input_feature_key Only used if use_deprecated_input_fn is false. String key into the features dict returned by input_fn that corresponds to a the raw Example strings Tensor that the exported model will take as input. Can only be None if you're using a custom signature_fn that does not use the first arg (examples).
use_deprecated_input_fn Determines the signature format of input_fn.
signature_fn Function that returns a default signature and a named signature map, given Tensor of Example strings, dict of Tensors for features and Tensor or dict of Tensors for predictions.
prediction_key The key for a tensor in the predictions dict (output from the model_fn) to use as the predictions input to the signature_fn. Optional. If None, predictions will pass to signature_fn without filtering.
default_batch_size Default batch size of the Example placeholder.
exports_to_keep Number of exports to keep.
checkpoint_path the checkpoint path of the model to be exported. If it is None (which is default), will use the latest checkpoint in export_dir.

Returns
The string path to the exported directory. NB: this functionality was added ca. 2016/09/25; clients that depend on the return value may need to handle the case where this function returns None because subclasses are not returning a value.

export_savedmodel

View source

export_savedmodel(
    export_dir_base, serving_input_fn, default_output_alternative_key=None,
    assets_extra=None, as_text=False, checkpoint_path=None,
    graph_rewrite_specs=(GraphRewriteSpec((tag_constants.SERVING,), ()),),
    strip_default_attrs=False
)

Exports inference graph as a SavedModel into given dir.

Args
export_dir_base A string containing a directory to write the exported graph and checkpoints.
serving_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. Not needed for single-headed models.
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.
checkpoint_path The checkpoint path to export. If None (the default), the most recent checkpoint found within the model directory is chosen.
graph_rewrite_specs an iterable of GraphRewriteSpec. Each element will produce a separate MetaGraphDef within the exported SavedModel, tagged and rewritten as specified. Defaults to a single entry using the default serving tag ("serve") and no rewriting.
strip_default_attrs Boolean. If True, default-valued attributes will be removed from the NodeDefs. For a detailed guide, see Stripping Default-Valued Attributes.

Returns
The string path to the exported directory.

Raises
ValueError if an unrecognized export_type is requested.

fit

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fit(
    x=None, y=None, input_fn=None, steps=None, batch_size=None, monitors=None,
    max_steps=None
)

See Trainable. (deprecated arguments)

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

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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

View source

get_variable_names()

Returns list of all variable names in this model.

Returns
List of names.

get_variable_value

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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

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partial_fit(
    x=None, y=None, input_fn=None, steps=1, batch_size=None, monitors=None
)

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

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

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predict(
    x=None, input_fn=None, batch_size=None, outputs=None, as_iterable=True,
    iterate_batches=False
)

Returns predictions for given features. (deprecated arguments)

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.
input_fn Input function. If set, x and 'batch_size' must be None.
batch_size Override default batch size. If set, 'input_fn' must be 'None'.
outputs list of str, name of the output to predict. If None, returns all.
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).
iterate_batches If True, yield the whole batch at once instead of decomposing the batch into individual samples. Only relevant when as_iterable is True.

Returns
A numpy array of predicted classes or regression values if the constructor's model_fn returns a Tensor for predictions or a dict of numpy arrays if model_fn returns a dict. Returns an iterable of predictions if as_iterable is True.

Raises
ValueError If x and input_fn are both provided or both None.

set_params

View source

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.

Returns
self

Raises
ValueError If params contain invalid names.