tfdf.keras.DistributedGradientBoostedTreesModel

Distributed Gradient Boosted Trees learning algorithm.

Inherits From: DistributedGradientBoostedTreesModel, CoreModel

Exact distributed version of the Gradient Boosted Tree learning algorithm. See the documentation of the non-distributed Gradient Boosted Tree learning algorithm for an introduction to GBTs.

Usage example:

import tensorflow_decision_forests as tfdf
import pandas as pd

dataset = pd.read_csv("project/dataset.csv")
tf_dataset = tfdf.keras.pd_dataframe_to_tf_dataset(dataset, label="my_label")

model = tfdf.keras.DistributedGradientBoostedTreesModel()
model.fit(tf_dataset)

print(model.summary())

Hyper-parameter tuning:

import tensorflow_decision_forests as tfdf
import pandas as pd

dataset = pd.read_csv("project/dataset.csv")
tf_dataset = tfdf.keras.pd_dataframe_to_tf_dataset(dataset, label="my_label")

tuner = tfdf.tuner.RandomSearch(num_trials=20)

# Hyper-parameters to optimize.
tuner.discret("max_depth", [4, 5, 6, 7])

model = tfdf.keras.DistributedGradientBoostedTreesModel(tuner=tuner)
model.fit(tf_dataset)

print(model.summary())

task Task to solve (e.g. Task.CLASSIFICATION, Task.REGRESSION, Task.RANKING, Task.CATEGORICAL_UPLIFT, Task.NUMERICAL_UPLIFT).
features Specify the list and semantic of the input features of the model. If not specified, all the available features will be used. If specified and if exclude_non_specified_features=True, only the features in features will be used by the model. If "preprocessing" is used, features corresponds to the output of the preprocessing. In this case, it is recommended for the preprocessing to return a dictionary of tensors.
exclude_non_specified_features If true, only use the features specified in features.
preprocessing Functional keras model or @tf.function to apply on the input feature before the model to train. This preprocessing model can consume and return tensors, list of tensors or dictionary of tensors. If specified, the model only "sees" the output of the preprocessing (and not the raw input). Can be used to prepare the features or to stack multiple models on top of each other. Unlike preprocessing done in the tf.dataset, the operation in "preprocessing" are serialized with the model.
postprocessing Like "preprocessing" but applied on the model output.
ranking_group Only for task=Task.RANKING. Name of a tf.string feature that identifies queries in a query/document ranking task. The ranking group is not added automatically for the set of features if exclude_non_specified_features=false.
uplift_treatment Only for task=Task.CATEGORICAL_UPLIFT or task=Task.NUMERICAL_UPLIFT. Name of an integer feature that identifies the treatment in an uplift problem. The value 0 is reserved for the control treatment.
temp_directory Temporary directory used to store the model Assets after the training, and possibly as a work directory during the training. This temporary directory is necessary for the model to be exported after training e.g. model.save(path). If not specified, temp_directory is set to a temporary directory using tempfile.TemporaryDirectory. This directory is deleted when the model python object is garbage-collected.
verbose Verbosity mode. 0 = silent, 1 = small details, 2 = full details.
hyperparameter_template Override the default value of the hyper-parameters. If None (default) the default parameters of the library are used. If set, default_hyperparameter_template refers to one of the following preconfigured hyper-parameter sets. Those sets outperforms the default hyper-parameters (either generally or in specific scenarios). You can omit the version (e.g. remove "@v5") to use the last version of the template. In this case, the hyper-parameter can change in between releases (not recommended for training in production).
advanced_arguments Advanced control of the model that most users won't need to use. See AdvancedArguments for details.
num_threads Number of threads used to train the model. Different learning algorithms use multi-threading differently and with different degree of efficiency. If None, num_threads will be automatically set to the number of processors (up to a maximum of 32; or set to 6 if the number of processors is not available). Making num_threads significantly larger than the number of processors can slow-down the training speed. The default value logic might change in the future.
name The name of the model.
max_vocab_count Default maximum size of the vocabulary for CATEGORICAL and CATEGORICAL_SET features stored as strings. If more unique values exist, only the most frequent values are kept, and the remaining values are considered as out-of-vocabulary. The value max_vocab_count defined in a FeatureUsage (if any) takes precedence.
try_resume_training If true, the model training resumes from the checkpoint stored in the temp_directory directory. If temp_directory does not contain any model checkpoint, the training start from the beginning. Resuming training is useful in the following situations: (1) The training was interrupted by the user (e.g. ctrl+c or "stop" button in a notebook). (2) the training job was interrupted (e.g. rescheduling), ond (3) the hyper-parameter of the model were changed such that an initially completed training is now incomplete (e.g. increasing the number of trees). Note: Training can only be resumed if the training datasets is exactly the same (i.e. no reshuffle in the tf.data.Dataset).
check_dataset If set to true, test if the dataset is well configured for the training: (1) Check if the dataset does contains any repeat operations, (2) Check if the dataset does contain a batch operation, (3) Check if the dataset has a large enough batch size (min 100 if the dataset contains more than 1k examples or if the number of examples is not available) If set to false, do not run any test.
tuner If set, automatically optimize the hyperparameters of the model using this tuner. If the model is trained with distribution (i.e. the model definition is wrapper in a TF Distribution strategy, the tuning is distributed.
discretize_numerical_features If true, discretize all the numerical features before training. Discretized numerical features are faster to train with, but they can have a negative impact on the model quality. Using discretize_numerical_features=True is equivalent as setting the feature semantic DISCRETIZED_NUMERICAL in the feature argument. See the definition of DISCRETIZED_NUMERICAL for more details.
num_discretize_numerical_bins Number of bins used when disretizing numerical features. The value num_discretized_numerical_bins defined in a FeatureUsage (if any) takes precedence.
apply_link_function If true, applies the link function (a.k.a. activation function), if any, before returning the model prediction. If false, returns the pre-link function model output. For example, in the case of binary classification, the pre-link function output is a logic while the post-link function is a probability. Default: True.
force_numerical_discretization If false, only the numerical column safisfying "max_unique_values_for_discretized_numerical" will be discretized. If true, all the numerical columns will be discretized. Columns with more than "max_unique_values_for_discretized_numerical" unique values will be approximated with "max_unique_values_for_discretized_numerical" bins. This parameter will impact the model training. Default: False.
max_depth Maximum depth of the tree. max_depth=1 means that all trees will be roots. Negative values are ignored. Default: 6.
max_unique_values_for_discretized_numerical Maximum number of unique value of a numerical feature to allow its pre-discretization. In case of large datasets, discretized numerical features with a small number of unique values are more efficient to learn than classical / non-discretized numerical features. This parameter does not impact the final model. However, it can speed-up or slown the training. Default: 16000.
maximum_model_size_in_memory_in_bytes Limit the size of the model when stored in ram. Different algorithms can enforce this limit differently. Note that when models are compiled into an inference, the size of the inference engine is generally much smaller than the original model. Default: -1.0.
maximum_training_duration_seconds Maximum training duration of the model expressed in seconds. Each learning algorithm is free to use this parameter at it sees fit. Enabling maximum training duration makes the model training non-deterministic. Default: -1.0.
min_examples Minimum number of examples in a node. Default: 5.
num_candidate_attributes Number of unique valid attributes tested for each node. An attribute is valid if it has at least a valid split. If num_candidate_attributes=0, the value is set to the classical default value for Random Forest: sqrt(number of input attributes) in case of classification and number_of_input_attributes / 3 in case of regression. If num_candidate_attributes=-1, all the attributes are tested. Default: -1.
num_candidate_attributes_ratio Ratio of attributes tested at each node. If set, it is equivalent to num_candidate_attributes = number_of_input_features x num_candidate_attributes_ratio. The possible values are between ]0, and 1] as well as -1. If not set or equal to -1, the num_candidate_attributes is used. Default: -1.0.
num_trees Maximum number of decision trees. The effective number of trained tree can be smaller if early stopping is enabled. Default: 300.
pure_serving_model Clear the model from any information that is not required for model serving. This includes debugging, model interpretation and other meta-data. The size of the serialized model can be reduced significatively (50% model size reduction is common). This parameter has no impact on the quality, serving speed or RAM usage of model serving. Default: False.
random_seed Random seed for the training of the model. Learners are expected to be deterministic by the random seed. Default: 123456.
shrinkage Coefficient applied to each tree prediction. A small value (0.02) tends to give more accurate results (assuming enough trees are trained), but results in larger models. Analogous to neural network learning rate. Default: 0.1.
use_hessian_gain Use true, uses a formulation of split gain with a hessian term i.e. optimizes the splits to minimize the variance of "gradient / hessian. Available for all losses except regression. Default: False.
worker_logs If true, workers will print training logs. Default: True.
activity_regularizer Optional regularizer function for the output of this layer.
compute_dtype The dtype of the layer's computations.

This is equivalent to Layer.dtype_policy.compute_dtype. Unless mixed precision is used, this is the same as Layer.dtype, the dtype of the weights.

Layers automatically cast their inputs to the compute dtype, which causes computations and the output to be in the compute dtype as well. This is done by the base Layer class in Layer.call, so you do not have to insert these casts if implementing your own layer.

Layers often perform certain internal computations in higher precision when compute_dtype is float16 or bfloat16 for numeric stability. The output will still typically be float16 or bfloat16 in such cases.

distribute_strategy The tf.distribute.Strategy this model was created under.
dtype The dtype of the layer weights.

This is equivalent to Layer.dtype_policy.variable_dtype. Unless mixed precision is used, this is the same as Layer.compute_dtype, the dtype of the layer's computations.

dtype_policy The dtype policy associated with this layer.

This is an instance of a tf.keras.mixed_precision.Policy.

dynamic Whether the layer is dynamic (eager-only); set in the constructor.
input Retrieves the input tensor(s) of a layer.

Only applicable if the layer has exactly one input, i.e. if it is connected to one incoming layer.

input_spec InputSpec instance(s) describing the input format for this layer.

When you create a layer subclass, you can set self.input_spec to enable the layer to run input compatibility checks when it is called. Consider a Conv2D layer: it can only be called on a single input tensor of rank 4. As such, you can set, in __init__():

self.input_spec = tf.keras.layers.InputSpec(ndim=4)

Now, if you try to call the layer on an input that isn't rank 4 (for instance, an input of shape (2,), it will raise a nicely-formatted error:

ValueError: Input 0 of layer conv2d is incompatible with the layer:
expected ndim=4, found ndim=1. Full shape received: [2]

Input checks that can be specified via input_spec include:

  • Structure (e.g. a single input, a list of 2 inputs, etc)
  • Shape
  • Rank (ndim)
  • Dtype

For more information, see tf.keras.layers.InputSpec.

layers

learner Name of the learning algorithm used to train the model.
learner_params Gets the dictionary of hyper-parameters passed in the model constructor.

Changing this dictionary will impact the training.

losses List of losses added using the add_loss() API.

Variable regularization tensors are created when this property is accessed, so it is eager safe: accessing losses under a tf.GradientTape will propagate gradients back to the corresponding variables.

class MyLayer(tf.keras.layers.Layer):
  def call(self, inputs):
    self.add_loss(tf.abs(tf.reduce_mean(inputs)))
    return inputs
l = MyLayer()
l(np.ones((10, 1)))
l.losses
[1.0]
inputs = tf.keras.Input(shape=(10,))
x = tf.keras.layers.Dense(10)(inputs)
outputs = tf.keras.layers.Dense(1)(x)
model = tf.keras.Model(inputs, outputs)
# Activity regularization.
len(model.losses)
0
model.add_loss(tf.abs(tf.reduce_mean(x)))
len(model.losses)
1
inputs = tf.keras.Input(shape=(10,))
d = tf.keras.layers.Dense(10, kernel_initializer='ones')
x = d(inputs)
outputs = tf.keras.layers.Dense(1)(x)
model = tf.keras.Model(inputs, outputs)
# Weight regularization.
model.add_loss(lambda: tf.reduce_mean(d.kernel))
model.losses
[<tf.Tensor: shape=(), dtype=float32, numpy=1.0>]

metrics Returns the model's metrics added using compile(), add_metric() APIs.

inputs = tf.keras.layers.Input(shape=(3,))
outputs = tf.keras.layers.Dense(2)(inputs)
model = tf.keras.models.Model(inputs=inputs, outputs=outputs)
model.compile(optimizer="Adam", loss="mse", metrics=["mae"])
[m.name for m in model.metrics]
[]
x = np.random.random((2, 3))
y = np.random.randint(0, 2, (2, 2))
model.fit(x, y)
[m.name for m in model.metrics]
['loss', 'mae']
inputs = tf.keras.layers.Input(shape=(3,))
d = tf.keras.layers.Dense(2, name='out')
output_1 = d(inputs)
output_2 = d(inputs)
model = tf.keras.models.Model(
   inputs=inputs, outputs=[output_1, output_2])
model.add_metric(
   tf.reduce_sum(output_2), name='mean', aggregation='mean')
model.compile(optimizer="Adam", loss="mse", metrics=["mae", "acc"])
model.fit(x, (y, y))
[m.name for m in model.metrics]
['loss', 'out_loss', 'out_1_loss', 'out_mae', 'out_acc', 'out_1_mae',
'out_1_acc', 'mean']

metrics_names Returns the model's display labels for all outputs.

inputs = tf.keras.layers.Input(shape=(3,))
outputs = tf.keras.layers.Dense(2)(inputs)
model = tf.keras.models.Model(inputs=inputs, outputs=outputs)
model.compile(optimizer="Adam", loss="mse", metrics=["mae"])
model.metrics_names
[]
x = np.random.random((2, 3))
y = np.random.randint(0, 2, (2, 2))
model.fit(x, y)
model.metrics_names
['loss', 'mae']
inputs = tf.keras.layers.Input(shape=(3,))
d = tf.keras.layers.Dense(2, name='out')
output_1 = d(inputs)
output_2 = d(inputs)
model = tf.keras.models.Model(
   inputs=inputs, outputs=[output_1, output_2])
model.compile(optimizer="Adam", loss="mse", metrics=["mae", "acc"])
model.fit(x, (y, y))
model.metrics_names
['loss', 'out_loss', 'out_1_loss', 'out_mae', 'out_acc', 'out_1_mae',
'out_1_acc']

name_scope Returns a tf.name_scope instance for this class.
non_trainable_weights List of all non-trainable weights tracked by this layer.

Non-trainable weights are not updated during training. They are expected to be updated manually in call().

num_training_examples Number of training examples.
num_validation_examples Number of validation examples.
output Retrieves the output tensor(s) of a layer.

Only applicable if the layer has exactly one output, i.e. if it is connected to one incoming layer.

run_eagerly Settable attribute indicating whether the model should run eagerly.

Running eagerly means that your model will be run step by step, like Python code. Your model might run slower, but it should become easier for you to debug it by stepping into individual layer calls.

By default, we will attempt to compile your model to a static graph to deliver the best execution performance.

submodules Sequence of all sub-modules.

Submodules are modules which are properties of this module, or found as properties of modules which are properties of this module (and so on).

a = tf.Module()
b = tf.Module()
c = tf.Module()
a.b = b
b.c = c
list(a.submodules) == [b, c]
True
list(b.submodules) == [c]
True
list(c.submodules) == []
True

supports_masking Whether this layer supports computing a mask using compute_mask.
trainable

trainable_weights List of all trainable weights tracked by this layer.

Trainable weights are updated via gradient descent during training.

training_model_id Identifier of the model.
variable_dtype Alias of Layer.dtype, the dtype of the weights.
weights Returns the list of all layer variables/weights.

Methods

add_loss

Add loss tensor(s), potentially dependent on layer inputs.

Some losses (for instance, activity regularization losses) may be dependent on the inputs passed when calling a layer. Hence, when reusing the same layer on different inputs a and b, some entries in layer.losses may be dependent on a and some on b. This method automatically keeps track of dependencies.

This method can be used inside a subclassed layer or model's call function, in which case losses should be a Tensor or list of Tensors.

Example:

class MyLayer(tf.keras.layers.Layer):
  def call(self, inputs):
    self.add_loss(tf.abs(tf.reduce_mean(inputs)))
    return inputs

This method can also be called directly on a Functional Model during construction. In this case, any loss Tensors passed to this Model must be symbolic and be able to be traced back to the model's Inputs. These losses become part of the model's topology and are tracked in get_config.

Example:

inputs = tf.keras.Input(shape=(10,))
x = tf.keras.layers.Dense(10)(inputs)
outputs = tf.keras.layers.Dense(1)(x)
model = tf.keras.Model(inputs, outputs)
# Activity regularization.
model.add_loss(tf.abs(tf.reduce_mean(x)))

If this is not the case for your loss (if, for example, your loss references a Variable of one of the model's layers), you can wrap your loss in a zero-argument lambda. These losses are not tracked as part of the model's topology since they can't be serialized.

Example:

inputs = tf.keras.Input(shape=(10,))
d = tf.keras.layers.Dense(10)
x = d(inputs)
outputs = tf.keras.layers.Dense(1)(x)
model = tf.keras.Model(inputs, outputs)
# Weight regularization.
model.add_loss(lambda: tf.reduce_mean(d.kernel))

Args
losses Loss tensor, or list/tuple of tensors. Rather than tensors, losses may also be zero-argument callables which create a loss tensor.
**kwargs Used for backwards compatibility only.

add_metric

Adds metric tensor to the layer.

This method can be used inside the call() method of a subclassed layer or model.

class MyMetricLayer(tf.keras.layers.Layer):
  def __init__(self):
    super(MyMetricLayer, self).__init__(name='my_metric_layer')
    self.mean = tf.keras.metrics.Mean(name='metric_1')

  def call(self, inputs):
    self.add_metric(self.mean(inputs))
    self.add_metric(tf.reduce_sum(inputs), name='metric_2')
    return inputs

This method can also be called directly on a Functional Model during construction. In this case, any tensor passed to this Model must be symbolic and be able to be traced back to the model's Inputs. These metrics become part of the model's topology and are tracked when you save the model via save().

inputs = tf.keras.Input(shape=(10,))
x = tf.keras.layers.Dense(10)(inputs)
outputs = tf.keras.layers.Dense(1)(x)
model = tf.keras.Model(inputs, outputs)
model.add_metric(math_ops.reduce_sum(x), name='metric_1')
inputs = tf.keras.Input(shape=(10,))
x = tf.keras.layers.Dense(10)(inputs)
outputs = tf.keras.layers.Dense(1)(x)
model = tf.keras.Model(inputs, outputs)
model.add_metric(tf.keras.metrics.Mean()(x), name='metric_1')

Args
value Metric tensor.
name String metric name.
**kwargs Additional keyword arguments for backward compatibility. Accepted values: aggregation - When the value tensor provided is not the result of calling a keras.Metric instance, it will be aggregated by default using a keras.Metric.Mean.

build

Builds the model based on input shapes received.

This is to be used for subclassed models, which do not know at instantiation time what their inputs look like.

This method only exists for users who want to call model.build() in a standalone way (as a substitute for calling the model on real data to build it). It will never be called by the framework (and thus it will never throw unexpected errors in an unrelated workflow).

Args
input_shape Single tuple, TensorShape instance, or list/dict of shapes, where shapes are tuples, integers, or TensorShape instances.

Raises
ValueError

  1. In case of invalid user-provided data (not of type tuple, list, TensorShape, or dict).
  2. If the model requires call arguments that are agnostic to the input shapes (positional or keyword arg in call signature).
  3. If not all layers were properly built.
  4. If float type inputs are not supported within the layers.

In each of these cases, the user should build their model by calling it on real tensor data.

call

View source

Inference of the model.

This method is used for prediction and evaluation of a trained model.

Args
inputs Input tensors.
training Is the model being trained. Always False.

Returns
Model predictions.

call_get_leaves

View source

Computes the index of the active leaf in each tree.

The active leaf is the leave that that receive the example during inference.

The returned value "leaves[i,j]" is the index of the active leave for the i-th example and the j-th tree. Leaves are indexed by depth first exploration with the negative child visited before the positive one (similarly as "iterate_on_nodes()" iteration). Leaf indices are also available with LeafNode.leaf_idx.

Args
inputs Input tensors. Same signature as the model's "call(inputs)".

Returns
Index of the active leaf for each tree in the model.

capabilities

View source

Lists the capabilities of the learning algorithm.

collect_data_step

View source

Collect examples e.g. training or validation.

compile

View source

Configure the model for training.

Unlike for most Keras model, calling "compile" is optional before calling "fit".

Args
metrics List of metrics to be evaluated by the model during training and testing.
weighted_metrics List of metrics to be evaluated and weighted by sample_weight or class_weight during training and testing.

Raises
ValueError Invalid arguments.

compute_loss

Compute the total loss, validate it, and return it.

Subclasses can optionally override this method to provide custom loss computation logic.

Example:

class MyModel(tf.keras.Model):

  def __init__(self, *args, **kwargs):
    super(MyModel, self).__init__(*args, **kwargs)
    self.loss_tracker = tf.keras.metrics.Mean(name='loss')

  def compute_loss(self, x, y, y_pred, sample_weight):
    loss = tf.reduce_mean(tf.math.squared_difference(y_pred, y))
    loss += tf.add_n(self.losses)
    self.loss_tracker.update_state(loss)
    return loss

  def reset_metrics(self):
    self.loss_tracker.reset_states()

  @property
  def metrics(self):
    return [self.loss_tracker]

tensors = tf.random.uniform((10, 10)), tf.random.uniform((10,))
dataset = tf.data.Dataset.from_tensor_slices(tensors).repeat().batch(1)

inputs = tf.keras.layers.Input(shape=(10,), name='my_input')
outputs = tf.keras.layers.Dense(10)(inputs)
model = MyModel(inputs, outputs)
model.add_loss(tf.reduce_sum(outputs))

optimizer = tf.keras.optimizers.SGD()
model.compile(optimizer, loss='mse', steps_per_execution=10)
model.fit(dataset, epochs=2, steps_per_epoch=10)
print('My custom loss: ', model.loss_tracker.result().numpy())

Args
x Input data.
y Target data.
y_pred Predictions returned by the model (output of model(x))
sample_weight Sample weights for weighting the loss function.

Returns
The total loss as a tf.Tensor, or None if no loss results (which is the case when called by Model.test_step).

compute_mask

Computes an output mask tensor.

Args
inputs Tensor or list of tensors.
mask Tensor or list of tensors.

Returns
None or a tensor (or list of tensors, one per output tensor of the layer).

compute_metrics

Update metric states and collect all metrics to be returned.

Subclasses can optionally override this method to provide custom metric updating and collection logic.

Example:

class MyModel(tf.keras.Sequential):

  def compute_metrics(self, x, y, y_pred, sample_weight):

    # This super call updates `self.compiled_metrics` and returns results
    # for all metrics listed in `self.metrics`.
    metric_results = super(MyModel, self).compute_metrics(
        x, y, y_pred, sample_weight)

    # Note that `self.custom_metric` is not listed in `self.metrics`.
    self.custom_metric.update_state(x, y, y_pred, sample_weight)
    metric_results['custom_metric_name'] = self.custom_metric.result()
    return metric_results

Args
x Input data.
y Target data.
y_pred Predictions returned by the model (output of model.call(x))
sample_weight Sample weights for weighting the loss function.

Returns
A dict containing values that will be passed to tf.keras.callbacks.CallbackList.on_train_batch_end(). Typically, the values of the metrics listed in self.metrics are returned. Example: {'loss': 0.2, 'accuracy': 0.7}.

compute_output_shape

Computes the output shape of the layer.

This method will cause the layer's state to be built, if that has not happened before. This requires that the layer will later be used with inputs that match the input shape provided here.

Args
input_shape Shape tuple (tuple of integers) or list of shape tuples (one per output tensor of the layer). Shape tuples can include None for free dimensions, instead of an integer.

Returns
An input shape tuple.

count_params

Count the total number of scalars composing the weights.

Returns
An integer count.

Raises
ValueError if the layer isn't yet built (in which case its weights aren't yet defined).

evaluate

Returns the loss value & metrics values for the model in test mode.

Computation is done in batches (see the batch_size arg.)

Args
x Input data. It could be:

  • A Numpy array (or array-like), or a list of arrays (in case the model has multiple inputs).
  • A TensorFlow tensor, or a list of tensors (in case the model has multiple inputs).
  • A dict mapping input names to the corresponding array/tensors, if the model has named inputs.
  • A tf.data dataset. Should return a tuple of either (inputs, targets) or (inputs, targets, sample_weights).
  • A generator or keras.utils.Sequence returning (inputs, targets) or (inputs, targets, sample_weights). A more detailed description of unpacking behavior for iterator types (Dataset, generator, Sequence) is given in the Unpacking behavior for iterator-like inputs section of Model.fit.
y Target data. Like the input data x, it could be either Numpy array(s) or TensorFlow tensor(s). It should be consistent with x (you cannot have Numpy inputs and tensor targets, or inversely). If x is a dataset, generator or keras.utils.Sequence instance, y should not be specified (since targets will be obtained from the iterator/dataset).
batch_size Integer or None. Number of samples per batch of computation. If unspecified, batch_size will default to 32. Do not specify the batch_size if your data is in the form of a dataset, generators, or keras.utils.Sequence instances (since they generate batches).
verbose "auto", 0, 1, or 2. Verbosity mode. 0 = silent, 1 = progress bar, 2 = single line. "auto" defaults to 1 for most cases, and to 2 when used with ParameterServerStrategy. Note that the progress bar is not particularly useful when logged to a file, so verbose=2 is recommended when not running interactively (e.g. in a production environment).
sample_weight Optional Numpy array of weights for the test samples, used for weighting the loss function. You can either pass a flat (1D) Numpy array with the same length as the input samples (1:1 mapping between weights and samples), or in the case of temporal data, you can pass a 2D array with shape (samples, sequence_length), to apply a different weight to every timestep of every sample. This argument is not supported when x is a dataset, instead pass sample weights as the third element of x.
steps Integer or None. Total number of steps (batches of samples) before declaring the evaluation round finished. Ignored with the default value of None. If x is a tf.data dataset and steps is None, 'evaluate' will run until the dataset is exhausted. This argument is not supported with array inputs.
callbacks List of keras.callbacks.Callback instances. List of callbacks to apply during evaluation. See callbacks.
max_queue_size Integer. Used for generator or keras.utils.Sequence input only. Maximum size for the generator queue. If unspecified, max_queue_size will default to 10.
workers Integer. Used for generator or keras.utils.Sequence input only. Maximum number of processes to spin up when using process-based threading. If unspecified, workers will default to 1.
use_multiprocessing Boolean. Used for generator or keras.utils.Sequence input only. If True, use process-based threading. If unspecified, use_multiprocessing will default to False. Note that because this implementation relies on multiprocessing, you should not pass non-picklable arguments to the generator as they can't be passed easily to children processes.
return_dict If True, loss and metric results are returned as a dict, with each key being the name of the metric. If False, they are returned as a list.
**kwargs Unused at this time.

See the discussion of Unpacking behavior for iterator-like inputs for Model.fit.

Returns
Scalar test loss (if the model has a single output and no metrics) or list of scalars (if the model has multiple outputs and/or metrics). The attribute model.metrics_names will give you the display labels for the scalar outputs.

Raises
RuntimeError If model.evaluate is wrapped in a tf.function.

fit

View source

Trains the model.

Local training

It is recommended to use a Pandas Dataframe dataset and to convert it to a TensorFlow dataset with "pd_dataframe_to_tf_dataset()":

pd_dataset = pandas.Dataframe(...) tf_dataset = pd_dataframe_to_tf_dataset(dataset, label="my_label") model.fit(pd_dataset)

The following dataset formats are supported:

  1. "x" is a tf.data.Dataset containing a tuple "(features, labels)". "features" can be a dictionary a tensor, a list of tensors or a dictionary of tensors (recommended). "labels" is a tensor.

  2. "x" is a tensor, list of tensors or dictionary of tensors containing the input features. "y" is a tensor.

  3. "x" is a numpy-array, list of numpy-arrays or dictionary of numpy-arrays containing the input features. "y" is a numpy-array.

  1. The dataset need to be read exactly once. If you use a TensorFlow dataset, make sure NOT to add a "repeat" operation.
  2. The algorithm does not benefit from shuffling the dataset. If you use a TensorFlow dataset, make sure NOT to add a "shuffle" operation.
  3. The dataset needs to be batched (i.e. with a "batch" operation). However, the number of elements per batch has not impact on the model. Generally, it is recommended to use batches as large as possible as its speeds-up reading the dataset in TensorFlow.

Input features do not need to be normalized (e.g. dividing numerical values by the variance) or indexed (e.g. replacing categorical string values by an integer). Additionnaly, missing values can be consumed natigely.

Distributed training

Some of the learning algorithms will support distributed training with the ParameterServerStrategy.

In this case, the dataset is read asynchronously in between the workers. The distribution of the training depends on the learning algorithm.

Like for non-distributed training, the dataset should be read eactly once. The simplest solution is to divide the dataset into different files (i.e. shards) and have each of the worker read a non overlapping subset of shards.

Currently (to be changed), the validation dataset (if provided) is simply feed to the "model.evaluate()" method. Therefore, it should satify Keras' evaluate API. Notably, for distributed training, the validation dataset should be infinite (i.e. have a repeat operation).

See https://www.tensorflow.org/decision_forests/distributed_training for more details and examples.

Here is a single example of distributed training using PSS for both dataset reading and training distribution.

def dataset_fn(context, paths, training=True): ds_path = tf.data.Dataset.from_tensor_slices(paths)

if context is not None:
  # Train on at least 2 workers.
  current_worker = tfdf.keras.get_worker_idx_and_num_workers(context)
  assert current_worker.num_workers > 2

  # Split the dataset's examples among the workers.
  ds_path = ds_path.shard(
      num_shards=current_worker.num_workers,
      index=current_worker.worker_idx)

def read_csv_file(path):
  numerical = tf.constant([math.nan], dtype=tf.float32)
  categorical_string = tf.constant([""], dtype=tf.string)
  csv_columns = [
      numerical,  # age
      categorical_string,  # workclass
      numerical,  # fnlwgt
      ...
  ]
  column_names = [
    "age", "workclass", "fnlwgt", ...
  ]
  label_name = "label"
  return tf.data.experimental.CsvDataset(path, csv_columns, header=True)

ds_columns = ds_path.interleave(read_csv_file)

def map_features(*columns):
  assert len(column_names) == len(columns)
  features = {column_names[i]: col for i, col in enumerate(columns)}
  label = label_table.lookup(features.pop(label_name))
  return features, label

ds_dataset = ds_columns.map(map_features)
if not training:
  dataset = dataset.repeat(None)
ds_dataset = ds_dataset.batch(batch_size)
return ds_dataset

strategy = tf.distribute.experimental.ParameterServerStrategy(...) sharded_train_paths = [list of dataset files] with strategy.scope(): model = DistributedGradientBoostedTreesModel() train_dataset = strategy.distribute_datasets_from_function( lambda context: dataset_fn(context, sharded_train_paths))

test_dataset = strategy.distribute_datasets_from_function(
  lambda context: dataset_fn(context, sharded_test_paths))

model.fit(sharded_train_paths) evaluation = model.evaluate(test_dataset, steps=num_test_examples // batch_size)

Args
x Training dataset (See details above for the supported formats).
y Label of the training dataset. Only used if "x" does not contains the labels.
callbacks Callbacks triggered during the training. The training runs in a single epoch, itself run in a single step. Therefore, callback logic can be called equivalently before/after the fit function.
verbose Verbosity mode. 0 = silent, 1 = small details, 2 = full details.
validation_steps Number of steps in the evaluation dataset when evaluating the trained model with model.evaluate(). If not specified, evaluates the model on the entire dataset (generally recommended; not yet supported for distributed datasets).
validation_data Validation dataset. If specified, the learner might use this dataset to help training e.g. early stopping.
sample_weight Training weights. Note: training weights can also be provided as the third output in a tf.data.Dataset e.g. (features, label, weights).
steps_per_epoch [Parameter will be removed] Number of training batch to load before training the model. Currently, only supported for distributed training.
class_weight For binary classification only. Mapping class indices (integers) to a weight (float) value. Only available for non-Distributed training. For maximum compatibility, feed example weights through the tf.data.Dataset or using the weight argument of pd_dataframe_to_tf_dataset.
**kwargs Extra arguments passed to the core keras model's fit. Note that not all keras' model fit arguments are supported.

Returns
A History object. Its History.history attribute is not yet implemented for decision forests algorithms, and will return empty. All other fields are filled as usual for Keras.Mode.fit().

fit_on_dataset_path

View source

Trains the model on a dataset stored on disk.

This solution is generally more efficient and easier that loading the dataset with a tf.Dataset both for local and distributed training.

Usage example

Local training

model = model = keras.GradientBoostedTreesModel() model.fit_on_dataset_path( train_path="/path/to/dataset.csv", label_key="label", dataset_format="csv") model.save("/model/path")

Distributed training

with tf.distribute.experimental.ParameterServerStrategy(...).scope(): model = model = keras.DistributedGradientBoostedTreesModel() model.fit_on_dataset_path( train_path="/path/to/dataset@10", label_key="label", dataset_format="tfrecord+tfe") model.save("/model/path")

Args
train_path: Path to the training dataset. Support comma separated files, shard and glob notation. label_key: Name of the label column. weight_key: Name of the weighing column. ranking_key: Name of the ranking column. valid_path: Path to the validation dataset. If not provided, or if the learning algorithm does not support/need a validation dataset, valid_path is ignored. dataset_format: Format of the dataset. Should be one of the registered dataset format (see https://github.com/google/yggdrasil-decision-forests/blob/main/documentation/user_manual.md#dataset-path-and-format for more details). The format "csv" always available but it is generally only suited for small datasets.
max_num_scanned_rows_to_accumulate_statistics Maximum number of examples to scan to determine the statistics of the features (i.e. the dataspec, e.g. mean value, dictionaries). (Currently) the "first" examples of the dataset are scanned (e.g. the first examples of the dataset is a single file). Therefore, it is important that the sampled dataset is relatively uniformly sampled, notably the scanned examples should contains all the possible categorical values (otherwise the not seen value will be treated as out-of-vocabulary). If set to None, the entire dataset is scanned. This parameter has no effect if the dataset is stored in a format that already contains those values.
try_resume_training If true, tries to resume training from the model checkpoint stored in the temp_directory directory. If temp_directory does not contain any model checkpoint, start the training from the start. Works in the following three situations: (1) The training was interrupted by the user (e.g. ctrl+c). (2) the training job was interrupted (e.g. rescheduling), ond (3) the hyper-parameter of the model were changed such that an initially completed training is now incomplete (e.g. increasing the number of trees).
input_model_signature_fn A lambda that returns the (Dense,Sparse,Ragged)TensorSpec (or structure of TensorSpec e.g. dictionary, list) corresponding to input signature of the model. If not specified, the input model signature is created by "build_default_input_model_signature". For example, specify "input_model_signature_fn" if an numerical input feature (which is consumed as DenseTensorSpec(float32) by default) will be feed differently (e.g. RaggedTensor(int64)).

Returns
A History object. Its History.history attribute is not yet implemented for decision forests algorithms, and will return empty. All other fields are filled as usual for Keras.Mode.fit().

from_config

Creates a layer from its config.

This method is the reverse of get_config, capable of instantiating the same layer from the config dictionary. It does not handle layer connectivity (handled by Network), nor weights (handled by set_weights).

Args
config A Python dictionary, typically the output of get_config.

Returns
A layer instance.

get_config

Returns the config of the Model.

Config is a Python dictionary (serializable) containing the configuration of an object, which in this case is a Model. This allows the Model to be be reinstantiated later (without its trained weights) from this configuration.

Note that get_config() does not guarantee to return a fresh copy of dict every time it is called. The callers should make a copy of the returned dict if they want to modify it.

Developers of subclassed Model are advised to override this method, and continue to update the dict from super(MyModel, self).get_config() to provide the proper configuration of this Model. The default config is an empty dict. Optionally, raise NotImplementedError to allow Keras to attempt a default serialization.

Returns
Python dictionary containing the configuration of this Model.

get_layer

Retrieves a layer based on either its name (unique) or index.

If name and index are both provided, index will take precedence. Indices are based on order of horizontal graph traversal (bottom-up).

Args
name String, name of layer.
index Integer, index of layer.

Returns
A layer instance.

get_weights

Retrieves the weights of the model.

Returns
A flat list of Numpy arrays.

load_weights

View source

No-op for TensorFlow Decision Forests models.

load_weights is not supported by TensorFlow Decision Forests models. To save and restore a model, use the SavedModel API i.e. model.save(...) and tf.keras.models.load_model(...). To resume the training of an existing model, create the model with try_resume_training=True (default value) and with a similar temp_directory argument. See documentation of try_resume_training for more details.

Args
*args Passed through to base keras.Model implemenation.
**kwargs Passed through to base keras.Model implemenation.

make_inspector

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Creates an inspector to access the internal model structure.

Usage example:

inspector = model.make_inspector()
print(inspector.num_trees())
print(inspector.variable_importances())

Returns
A model inspector.

make_predict_function

View source

Prediction of the model (!= evaluation).

make_test_function

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Predictions for evaluation.

make_train_function

Creates a function that executes one step of training.

This method can be overridden to support custom training logic. This method is called by Model.fit and Model.train_on_batch.

Typically, this method directly controls tf.function and tf.distribute.Strategy settings, and delegates the actual training logic to Model.train_step.

This function is cached the first time Model.fit or Model.train_on_batch is called. The cache is cleared whenever Model.compile is called. You can skip the cache and generate again the function with force=True.

Args
force Whether to regenerate the train function and skip the cached function if available.

Returns
Function. The function created by this method should accept a tf.data.Iterator, and return a dict containing values that will be passed to tf.keras.Callbacks.on_train_batch_end, such as {'loss': 0.2, 'accuracy': 0.7}.

predefined_hyperparameters

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Returns a better than default set of hyper-parameters.

They can be used directly with the hyperparameter_template argument of the model constructor.

These hyper-parameters outperform the default hyper-parameters (either generally or in specific scenarios). Like default hyper-parameters, existing pre-defined hyper-parameters cannot change.

predict

Generates output predictions for the input samples.

Computation is done in batches. This method is designed for batch processing of large numbers of inputs. It is not intended for use inside of loops that iterate over your data and process small numbers of inputs at a time.

For small numbers of inputs that fit in one batch, directly use __call__() for faster execution, e.g., model(x), or model(x, training=False) if you have layers such as tf.keras.layers.BatchNormalization that behave differently during inference. You may pair the individual model call with a tf.function for additional performance inside your inner loop. If you need access to numpy array values instead of tensors after your model call, you can use tensor.numpy() to get the numpy array value of an eager tensor.

Also, note the fact that test loss is not affected by regularization layers like noise and dropout.

Args
x Input samples. It could be:

  • A Numpy array (or array-like), or a list of arrays (in case the model has multiple inputs).
  • A TensorFlow tensor, or a list of tensors (in case the model has multiple inputs).
  • A tf.data dataset.
  • A generator or keras.utils.Sequence instance. A more detailed description of unpacking behavior for iterator types (Dataset, generator, Sequence) is given in the Unpacking behavior for iterator-like inputs section of Model.fit.
batch_size Integer or None. Number of samples per batch. If unspecified, batch_size will default to 32. Do not specify the batch_size if your data is in the form of dataset, generators, or keras.utils.Sequence instances (since they generate batches).
verbose "auto", 0, 1, or 2. Verbosity mode. 0 = silent, 1 = progress bar, 2 = single line. "auto" defaults to 1 for most cases, and to 2 when used with ParameterServerStrategy. Note that the progress bar is not particularly useful when logged to a file, so verbose=2 is recommended when not running interactively (e.g. in a production environment).
steps Total number of steps (batches of samples) before declaring the prediction round finished. Ignored with the default value of None. If x is a tf.data dataset and steps is None, predict() will run until the input dataset is exhausted.
callbacks List of keras.callbacks.Callback instances. List of callbacks to apply during prediction. See callbacks.
max_queue_size Integer. Used for generator or keras.utils.Sequence input only. Maximum size for the generator queue. If unspecified, max_queue_size will default to 10.
workers Integer. Used for generator or keras.utils.Sequence input only. Maximum number of processes to spin up when using process-based threading. If unspecified, workers will default to 1.
use_multiprocessing Boolean. Used for generator or keras.utils.Sequence input only. If True, use process-based threading. If unspecified, use_multiprocessing will default to False. Note that because this implementation relies on multiprocessing, you should not pass non-picklable arguments to the generator as they can't be passed easily to children processes.

See the discussion of Unpacking behavior for iterator-like inputs for Model.fit. Note that Model.predict uses the same interpretation rules as Model.fit and Model.evaluate, so inputs must be unambiguous for all three methods.

Returns
Numpy array(s) of predictions.

Raises
RuntimeError If model.predict is wrapped in a tf.function.
ValueError In case of mismatch between the provided input data and the model's expectations, or in case a stateful model receives a number of samples that is not a multiple of the batch size.

predict_get_leaves

View source

Gets the index of the active leaf of each tree.

The active leaf is the leave that that receive the example during inference.

The returned value "leaves[i,j]" is the index of the active leave for the i-th example and the j-th tree. Leaves are indexed by depth first exploration with the negative child visited before the positive one (similarly as "iterate_on_nodes()" iteration). Leaf indices are also available with LeafNode.leaf_idx.

Args
x Input samples as a tf.data.Dataset.

Returns
Index of the active leaf for each tree in the model.

predict_on_batch

Returns predictions for a single batch of samples.

Args
x Input data. It could be:

  • A Numpy array (or array-like), or a list of arrays (in case the model has multiple inputs).
  • A TensorFlow tensor, or a list of tensors (in case the model has multiple inputs).

Returns
Numpy array(s) of predictions.

Raises
RuntimeError If model.predict_on_batch is wrapped in a tf.function.

predict_step

The logic for one inference step.

This method can be overridden to support custom inference logic. This method is called by Model.make_predict_function.

This method should contain the mathematical logic for one step of inference. This typically includes the forward pass.

Configuration details for how this logic is run (e.g. tf.function and tf.distribute.Strategy settings), should be left to Model.make_predict_function, which can also be overridden.

Args
data A nested structure of Tensors.

Returns
The result of one inference step, typically the output of calling the Model on data.

reset_metrics

Resets the state of all the metrics in the model.

Examples:

inputs = tf.keras.layers.Input(shape=(3,))
outputs = tf.keras.layers.Dense(2)(inputs)
model = tf.keras.models.Model(inputs=inputs, outputs=outputs)
model.compile(optimizer="Adam", loss="mse", metrics=["mae"])
x = np.random.random((2, 3))
y = np.random.randint(0, 2, (2, 2))
_ = model.fit(x, y, verbose=0)
assert all(float(m.result()) for m in model.metrics)
model.reset_metrics()
assert all(float(m.result()) == 0 for m in model.metrics)

reset_states

save

View source

Saves the model as a TensorFlow SavedModel.

The exported SavedModel contains a standalone Yggdrasil Decision Forests model in the "assets" sub-directory. The Yggdrasil model can be used directly using the Yggdrasil API. However, this model does not contain the "preprocessing" layer (if any).

Args
filepath Path to the output model.
overwrite If true, override an already existing model. If false, raise an error if a model already exist.
**kwargs Arguments passed to the core keras model's save.

save_spec

Returns the tf.TensorSpec of call inputs as a tuple (args, kwargs).

This value is automatically defined after calling the model for the first time. Afterwards, you can use it when exporting the model for serving:

model = tf.keras.Model(...)

@tf.function
def serve(*args, **kwargs):
  outputs = model(*args, **kwargs)
  # Apply postprocessing steps, or add additional outputs.
  ...
  return outputs

# arg_specs is `[tf.TensorSpec(...), ...]`. kwarg_specs, in this example, is
# an empty dict since functional models do not use keyword arguments.
arg_specs, kwarg_specs = model.save_spec()

model.save(path, signatures={
  'serving_default': serve.get_concrete_function(*arg_specs, **kwarg_specs)
})

Args
dynamic_batch Whether to set the batch sizes of all the returned tf.TensorSpec to None. (Note that when defining functional or Sequential models with tf.keras.Input([...], batch_size=X), the batch size will always be preserved). Defaults to True.

Returns
If the model inputs are defined, returns a tuple (args, kwargs). All elements in args and kwargs are tf.TensorSpec. If the model inputs are not defined, returns None. The model inputs are automatically set when calling the model, model.fit, model.evaluate or model.predict.

save_weights

Saves all layer weights.

Either saves in HDF5 or in TensorFlow format based on the save_format argument.

When saving in HDF5 format, the weight file has:

  • layer_names (attribute), a list of strings (ordered names of model layers).
  • For every layer, a group named layer.name
    • For every such layer group, a group attribute weight_names, a list of strings (ordered names of weights tensor of the layer).
    • For every weight in the layer, a dataset storing the weight value, named after the weight tensor.

When saving in TensorFlow format, all objects referenced by the network are saved in the same format as tf.train.Checkpoint, including any Layer instances or Optimizer instances assigned to object attributes. For networks constructed from inputs and outputs using tf.keras.Model(inputs, outputs), Layer instances used by the network are tracked/saved automatically. For user-defined classes which inherit from tf.keras.Model, Layer instances must be assigned to object attributes, typically in the constructor. See the documentation of tf.train.Checkpoint and tf.keras.Model for details.

While the formats are the same, do not mix save_weights and tf.train.Checkpoint. Checkpoints saved by Model.save_weights should be loaded using Model.load_weights. Checkpoints saved using tf.train.Checkpoint.save should be restored using the corresponding tf.train.Checkpoint.restore. Prefer tf.train.Checkpoint over save_weights for training checkpoints.

The TensorFlow format matches objects and variables by starting at a root object, self for save_weights, and greedily matching attribute names. For Model.save this is the Model, and for Checkpoint.save this is the Checkpoint even if the Checkpoint has a model attached. This means saving a tf.keras.Model using save_weights and loading into a tf.train.Checkpoint with a Model attached (or vice versa) will not match the Model's variables. See the guide to training checkpoints for details on the TensorFlow format.

Args
filepath String or PathLike, path to the file to save the weights to. When saving in TensorFlow format, this is the prefix used for checkpoint files (multiple files are generated). Note that the '.h5' suffix causes weights to be saved in HDF5 format.
overwrite Whether to silently overwrite any existing file at the target location, or provide the user with a manual prompt.
save_format Either 'tf' or 'h5'. A filepath ending in '.h5' or '.keras' will default to HDF5 if save_format is None. Otherwise None defaults to 'tf'.
options Optional tf.train.CheckpointOptions object that specifies options for saving weights.

Raises
ImportError If h5py is not available when attempting to save in HDF5 format.

set_weights

Sets the weights of the layer, from NumPy arrays.

The weights of a layer represent the state of the layer. This function sets the weight values from numpy arrays. The weight values should be passed in the order they are created by the layer. Note that the layer's weights must be instantiated before calling this function, by calling the layer.

For example, a Dense layer returns a list of two values: the kernel matrix and the bias vector. These can be used to set the weights of another Dense layer:

layer_a = tf.keras.layers.Dense(1,
  kernel_initializer=tf.constant_initializer(1.))
a_out = layer_a(tf.convert_to_tensor([[1., 2., 3.]]))
layer_a.get_weights()
[array([[1.],
       [1.],
       [1.]], dtype=float32), array([0.], dtype=float32)]
layer_b = tf.keras.layers.Dense(1,
  kernel_initializer=tf.constant_initializer(2.))
b_out = layer_b(tf.convert_to_tensor([[10., 20., 30.]]))
layer_b.get_weights()
[array([[2.],
       [2.],
       [2.]], dtype=float32), array([0.], dtype=float32)]
layer_b.set_weights(layer_a.get_weights())
layer_b.get_weights()
[array([[1.],
       [1.],
       [1.]], dtype=float32), array([0.], dtype=float32)]

Args
weights a list of NumPy arrays. The number of arrays and their shape must match number of the dimensions of the weights of the layer (i.e. it should match the output of get_weights).

Raises
ValueError If the provided weights list does not match the layer's specifications.

summary

View source

Shows information about the model.

test_on_batch

Test the model on a single batch of samples.

Args
x Input data. It could be:

  • A Numpy array (or array-like), or a list of arrays (in case the model has multiple inputs).
  • A TensorFlow tensor, or a list of tensors (in case the model has multiple inputs).
  • A dict mapping input names to the corresponding array/tensors, if the model has named inputs.
y Target data. Like the input data x, it could be either Numpy array(s) or TensorFlow tensor(s). It should be consistent with x (you cannot have Numpy inputs and tensor targets, or inversely).
sample_weight Optional array of the same length as x, containing weights to apply to the model's loss for each sample. In the case of temporal data, you can pass a 2D array with shape (samples, sequence_length), to apply a different weight to every timestep of every sample.
reset_metrics If True, the metrics returned will be only for this batch. If False, the metrics will be statefully accumulated across batches.
return_dict If True, loss and metric results are returned as a dict, with each key being the name of the metric. If False, they are returned as a list.

Returns
Scalar test loss (if the model has a single output and no metrics) or list of scalars (if the model has multiple outputs and/or metrics). The attribute model.metrics_names will give you the display labels for the scalar outputs.

Raises
RuntimeError If model.test_on_batch is wrapped in a tf.function.

test_step

The logic for one evaluation step.

This method can be overridden to support custom evaluation logic. This method is called by Model.make_test_function.

This function should contain the mathematical logic for one step of evaluation. This typically includes the forward pass, loss calculation, and metrics updates.

Configuration details for how this logic is run (e.g. tf.function and tf.distribute.Strategy settings), should be left to Model.make_test_function, which can also be overridden.

Args
data A nested structure of Tensors.

Returns
A dict containing values that will be passed to tf.keras.callbacks.CallbackList.on_train_batch_end. Typically, the values of the Model's metrics are returned.

to_json

Returns a JSON string containing the network configuration.

To load a network from a JSON save file, use keras.models.model_from_json(json_string, custom_objects={}).

Args
**kwargs Additional keyword arguments to be passed to json.dumps().

Returns
A JSON string.

to_yaml

Returns a yaml string containing the network configuration.

To load a network from a yaml save file, use keras.models.model_from_yaml(yaml_string, custom_objects={}).

custom_objects should be a dictionary mapping the names of custom losses / layers / etc to the corresponding functions / classes.

Args
**kwargs Additional keyword arguments to be passed to yaml.dump().

Returns
A YAML string.

Raises
RuntimeError announces that the method poses a security risk

train_on_batch

Runs a single gradient update on a single batch of data.

Args
x Input data. It could be:

  • A Numpy array (or array-like), or a list of arrays (in case the model has multiple inputs).
  • A TensorFlow tensor, or a list of tensors (in case the model has multiple inputs).
  • A dict mapping input names to the corresponding array/tensors, if the model has named inputs.
y Target data. Like the input data x, it could be either Numpy array(s) or TensorFlow tensor(s).
sample_weight Optional array of the same length as x, containing weights to apply to the model's loss for each sample. In the case of temporal data, you can pass a 2D array with shape (samples, sequence_length), to apply a different weight to every timestep of every sample.
class_weight Optional dictionary mapping class indices (integers) to a weight (float) to apply to the model's loss for the samples from this class during training. This can be useful to tell the model to "pay more attention" to samples from an under-represented class.
reset_metrics If True, the metrics returned will be only for this batch. If False, the metrics will be statefully accumulated across batches.
return_dict If True, loss and metric results are returned as a dict, with each key being the name of the metric. If False, they are returned as a list.

Returns
Scalar training loss (if the model has a single output and no metrics) or list of scalars (if the model has multiple outputs and/or metrics). The attribute model.metrics_names will give you the display labels for the scalar outputs.

Raises
RuntimeError If model.train_on_batch is wrapped in a tf.function.

train_step

View source

Collects training examples.

valid_step

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Collects validation examples.

with_name_scope

Decorator to automatically enter the module name scope.

class MyModule(tf.Module):
  @tf.Module.with_name_scope
  def __call__(self, x):
    if not hasattr(self, 'w'):
      self.w = tf.Variable(tf.random.normal([x.shape[1], 3]))
    return tf.matmul(x, self.w)

Using the above module would produce tf.Variables and tf.Tensors whose names included the module name:

mod = MyModule()
mod(tf.ones([1, 2]))
<tf.Tensor: shape=(1, 3), dtype=float32, numpy=..., dtype=float32)>
mod.w
<tf.Variable 'my_module/Variable:0' shape=(2, 3) dtype=float32,
numpy=..., dtype=float32)>

Args
method The method to wrap.

Returns
The original method wrapped such that it enters the module's name scope.

yggdrasil_model_path_tensor

View source

Gets the path to yggdrasil model, if available.

The effective path can be obtained with:

yggdrasil_model_path_tensor().numpy().decode("utf-8")

Returns
Path to the Yggdrasil model.

yggdrasil_model_prefix

View source

Gets the prefix of the internal yggdrasil model.

__call__