View source on GitHub 
Gradient Boosted Trees learning algorithm.
Inherits From: GradientBoostedTreesModel
, CoreModel
tfdf.keras.GradientBoostedTreesModel(
*args, **kargs
)
Used in the notebooks
Used in the guide  Used in the tutorials 

A GBT (Gradient Boosted [Decision] Tree; https://statweb.stanford.edu/~jhf/ftp/trebst.pdf) is a set of shallow decision trees trained sequentially. Each tree is trained to predict and then "correct" for the errors of the previously trained trees (more precisely each tree predict the gradient of the loss relative to the model output).
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.GradientBoostedTreesModel()
model.fit(tf_dataset)
print(model.summary())
Hyperparameter 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)
# Hyperparameters to optimize.
tuner.discret("max_depth", [4, 5, 6, 7])
model = tfdf.keras.GradientBoostedTreesModel(tuner=tuner)
model.fit(tf_dataset)
print(model.summary())
Attributes  

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 garbagecollected.

verbose

Verbosity mode. 0 = silent, 1 = small details, 2 = full details. 
hyperparameter_template

Override the default value of the hyperparameters.
If None (default) the default parameters of the library are used. If set,
default_hyperparameter_template refers to one of the following
preconfigured hyperparameter sets. Those sets outperforms the default
hyperparameters (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 hyperparameter 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 multithreading 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 slowdown 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 outofvocabulary. 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 hyperparameter 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.

adapt_subsample_for_maximum_training_duration

Control how the maximum training duration (if set) is applied. If false, the training stop when the time is used. If true, the size of the sampled datasets used train individual trees are adapted dynamically so that all the trees are trained in time. Default: False. 
allow_na_conditions

If true, the tree training evaluates conditions of the
type X is NA i.e. X is missing . Default: False.

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 prelink function model output. For example, in the case of binary classification, the prelink function output is a logic while the postlink function is a probability. Default: True. 
categorical_algorithm

How to learn splits on categorical attributes.
CART : CART algorithm. Find categorical splits of the form "value \in
mask". The solution is exact for binary classification, regression and
ranking. It is approximated for multiclass classification. This is a
good first algorithm to use. In case of overfitting (very small
dataset, large dictionary), the "random" algorithm is a good
alternative.ONE_HOT : Onehot encoding. Find the optimal categorical split of the
form "attribute == param". This method is similar (but more efficient)
than converting converting each possible categorical value into a
boolean feature. This method is available for comparison purpose and
generally performs worse than other alternatives.RANDOM : Best splits among a set of random candidate. Find the a
categorical split of the form "value \in mask" using a random search.
This solution can be seen as an approximation of the CART algorithm.
This method is a strong alternative to CART. This algorithm is inspired
from section "5.1 Categorical Variables" of "Random Forest", 2001.
Default: "CART".

categorical_set_split_greedy_sampling

For categorical set splits e.g. texts. Probability for a categorical value to be a candidate for the positive set. The sampling is applied once per node (i.e. not at every step of the greedy optimization). Default: 0.1. 
categorical_set_split_max_num_items

For categorical set splits e.g. texts.
Maximum number of items (prior to the sampling). If more items are
available, the least frequent items are ignored. Changing this value is
similar to change the "max_vocab_count" before loading the dataset, with
the following exception: With max_vocab_count , all the remaining items
are grouped in a special Outofvocabulary item. With max_num_items ,
this is not the case. Default: 1.

categorical_set_split_min_item_frequency

For categorical set splits e.g. texts. Minimum number of occurrences of an item to be considered. Default: 1. 
compute_permutation_variable_importance

If true, compute the permutation variable importance of the model at the end of the training using the validation dataset. Enabling this feature can increase the training time significantly. Default: False. 
dart_dropout

Dropout rate applied when using the DART i.e. when forest_extraction=DART. Default: 0.01. 
early_stopping

Early stopping detects the overfitting of the model and
halts it training using the validation dataset controlled by
validation_ratio .
NONE : No early stopping. The model is trained entirely.MIN_LOSS_FINAL : No early stopping. However, the model is then
truncated to maximize the validation loss.LOSS_INCREASE : Stop the training when the validation does not
decrease for early_stopping_num_trees_look_ahead trees. Default:
"LOSS_INCREASE".

early_stopping_num_trees_look_ahead

Rolling number of trees used to detect validation loss increase and trigger early stopping. Default: 30. 
focal_loss_alpha

EXPERIMENTAL. Weighting parameter for focal loss,
positive samples weighted by alpha, negative samples by (1alpha). The
default 0.5 value means no active classlevel weighting. Only used with
focal loss i.e. loss="BINARY_FOCAL_LOSS" Default: 0.5.

focal_loss_gamma

EXPERIMENTAL. Exponent of the misprediction exponent term
in focal loss, corresponds to gamma parameter in
https://arxiv.org/pdf/1708.02002.pdf. Only used with focal loss i.e.
loss="BINARY_FOCAL_LOSS" Default: 2.0.

forest_extraction

How to construct the forest:

goss_alpha

Alpha parameter for the GOSS (Gradientbased OneSide Sampling; "See LightGBM: A Highly Efficient Gradient Boosting Decision Tree") sampling method. Default: 0.2. 
goss_beta

Beta parameter for the GOSS (Gradientbased OneSide Sampling) sampling method. Default: 0.1. 
growing_strategy

How to grow the tree.
LOCAL : Each node is split independently of the other nodes. In other
words, as long as a node satisfy the splits "constraints (e.g. maximum
depth, minimum number of observations), the node will be split. This is
the "classical" way to grow decision trees.BEST_FIRST_GLOBAL : The node with the best loss reduction among all
the nodes of the tree is selected for splitting. This method is also
called "best first" or "leafwise growth". See "Bestfirst decision
tree learning", Shi and "Additive logistic regression : A statistical
view of boosting", Friedman for more details. Default: "LOCAL".

honest

In honest trees, different training examples are used to infer the structure and the leaf values. This regularization technique trades examples for bias estimates. It might increase or reduce the quality of the model. See "Generalized Random Forests", Athey et al. In this paper, Honest trees are trained with the Random Forest algorithm with a sampling without replacement. Default: False. 
honest_fixed_separation

For honest trees only i.e. honest=true. If true, a new random separation is generated for each tree. If false, the same separation is used for all the trees (e.g., in Gradient Boosted Trees containing multiple trees). Default: False. 
honest_ratio_leaf_examples

For honest trees only i.e. honest=true. Ratio of examples used to set the leaf values. Default: 0.5. 
in_split_min_examples_check

Whether to check the min_examples constraint
in the split search (i.e. splits leading to one child having less than
min_examples examples are considered invalid) or before the split
search (i.e. a node can be derived only if it contains more than
min_examples examples). If false, there can be nodes with less than
min_examples training examples. Default: True.

keep_non_leaf_label_distribution

Whether to keep the node value (i.e. the distribution of the labels of the training examples) of nonleaf nodes. This information is not used during serving, however it can be used for model interpretation as well as hyper parameter tuning. This can take lots of space, sometimes accounting for half of the model size. Default: True. 
l1_regularization

L1 regularization applied to the training loss. Impact the tree structures and lead values. Default: 0.0. 
l2_categorical_regularization

L2 regularization applied to the training loss for categorical features. Impact the tree structures and lead values. Default: 1.0. 
l2_regularization

L2 regularization applied to the training loss for all features except the categorical ones. Default: 0.0. 
lambda_loss

Lambda regularization applied to certain training loss functions. Only for NDCG loss. Default: 1.0. 
loss

The loss optimized by the model. If not specified (DEFAULT) the loss
is selected automatically according to the \"task\" and label
statistics. For example, if task=CLASSIFICATION and the label has two
possible values, the loss will be set to BINOMIAL_LOG_LIKELIHOOD.
Possible values are:
DEFAULT : Select the loss automatically according to the task and
label statistics.BINOMIAL_LOG_LIKELIHOOD : Binomial log likelihood. Only valid for
binary classification.SQUARED_ERROR : Least square loss. Only valid for regression.MULTINOMIAL_LOG_LIKELIHOOD : Multinomial log likelihood i.e.
crossentropy. Only valid for binary or multiclass classification.LAMBDA_MART_NDCG5 : LambdaMART with NDCG5.XE_NDCG_MART : Cross Entropy Loss NDCG. See arxiv.org/abs/1911.09798.
Default: "DEFAULT".

max_depth

Maximum depth of the tree. max_depth=1 means that all trees
will be roots. Negative values are ignored. Default: 6.

max_num_nodes

Maximum number of nodes in the tree. Set to 1 to disable
this limit. Only available for growing_strategy=BEST_FIRST_GLOBAL .
Default: None.

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 nondeterministic. Default: 1.0. 
min_examples

Minimum number of examples in a node. Default: 5. 
missing_value_policy

Method used to handle missing attribute values.
GLOBAL_IMPUTATION : Missing attribute values are imputed, with the
mean (in case of numerical attribute) or the mostfrequentitem (in
case of categorical attribute) computed on the entire dataset (i.e. the
information contained in the data spec).LOCAL_IMPUTATION : Missing attribute values are imputed with the mean
(numerical attribute) or mostfrequentitem (in the case of categorical
attribute) evaluated on the training examples in the current node.RANDOM_LOCAL_IMPUTATION : Missing attribute values are imputed from
randomly sampled values from the training examples in the current node.
This method was proposed by Clinic et al. in "Random Survival Forests"
(https://projecteuclid.org/download/pdfview_1/euclid.aoas/1223908043).
Default: "GLOBAL_IMPUTATION".

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. 
random_seed

Random seed for the training of the model. Learners are expected to be deterministic by the random seed. Default: 123456. 
sampling_method

Control the sampling of the datasets used to train
individual trees.

selective_gradient_boosting_ratio

Ratio of the dataset used to train individual tree for the selective Gradient Boosting (Selective Gradient Boosting for Effective Learning to Rank; Lucchese et al; http://quickrank.isti.cnr.it/selectivedata/selectiveSIGIR2018.pdf) sampling method. Default: 0.01. 
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. 
sorting_strategy

How are sorted the numerical features in order to find
the splits

sparse_oblique_normalization

For sparse oblique splits i.e.
split_axis=SPARSE_OBLIQUE . Normalization applied on the features,
before applying the sparse oblique projections.
NONE : No normalization.STANDARD_DEVIATION : Normalize the feature by the estimated standard
deviation on the entire train dataset. Also known as ZScore
normalization.MIN_MAX : Normalize the feature by the range (i.e. maxmin) estimated
on the entire train dataset. Default: None.

sparse_oblique_num_projections_exponent

For sparse oblique splits i.e.
split_axis=SPARSE_OBLIQUE . Controls of the number of random projections
to test at each node as num_features^num_projections_exponent . Default:
None.

sparse_oblique_projection_density_factor

For sparse oblique splits i.e.
split_axis=SPARSE_OBLIQUE . Controls of the number of random projections
to test at each node as num_features^num_projections_exponent . Default:
None.

sparse_oblique_weights

For sparse oblique splits i.e.
split_axis=SPARSE_OBLIQUE . Possible values:
BINARY : The oblique weights are sampled in {1,1} (default).CONTINUOUS : The oblique weights are be sampled in [1,1]. Default:
None.

split_axis

What structure of split to consider for numerical features.
AXIS_ALIGNED : Axis aligned splits (i.e. one condition at a time).
This is the "classical" way to train a tree. Default value.SPARSE_OBLIQUE : Sparse oblique splits (i.e. splits one a small number
of features) from "Sparse Projection Oblique Random Forests", Tomita et
al., 2020. Default: "AXIS_ALIGNED".

subsample

Ratio of the dataset (sampling without replacement) used to train individual trees for the random sampling method. Default: 1.0. 
uplift_min_examples_in_treatment

For uplift models only. Minimum number of examples per treatment in a node. Default: 5. 
uplift_split_score

For uplift models only. Splitter score i.e. score
optimized by the splitters. The scores are introduced in "Decision trees
for uplift modeling with single and multiple treatments", Rzepakowski et
al. Notation: p probability / average value of the positive outcome,
q probability / average value in the control group.
KULLBACK_LEIBLER or KL :  p log (p/q)EUCLIDEAN_DISTANCE or ED : (pq)^2CHI_SQUARED or CS : (pq)^2/q
Default: "KULLBACK_LEIBLER".

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. 
validation_interval_in_trees

Evaluate the model on the validation set every "validation_interval_in_trees" trees. Increasing this value reduce the cost of validation and can impact the early stopping policy (as early stopping is only tested during the validation). Default: 1. 
validation_ratio

Ratio of the training dataset used to monitor the training. Require to be >0 if early stopping is enabled. Default: 0.1. 
activity_regularizer

Optional regularizer function for the output of this layer. 
compute_dtype

The dtype of the layer's computations.
This is equivalent to 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 Layers often perform certain internal computations in higher precision when

distribute_strategy

The tf.distribute.Strategy this model was created under.

dtype

The dtype of the layer weights.
This is equivalent to 
dtype_policy

The dtype policy associated with this layer.
This is an instance of a 
dynamic

Whether the layer is dynamic (eageronly); 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
Now, if you try to call the layer on an input that isn't rank 4
(for instance, an input of shape
Input checks that can be specified via
For more information, see 
layers


learner

Name of the learning algorithm used to train the model. 
learner_params

Gets the dictionary of hyperparameters 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

metrics

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

metrics_names

Returns the model's display labels for all outputs.

name_scope

Returns a tf.name_scope instance for this class.

non_trainable_weights

List of all nontrainable weights tracked by this layer.
Nontrainable weights are not updated during training. They are expected
to be updated manually in 
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 submodules.
Submodules are modules which are properties of this module, or found as properties of modules which are properties of this module (and so on).

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(
losses, **kwargs
)
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 Input
s. 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
zeroargument 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 zeroargument callables which create a loss tensor. 
**kwargs

Used for backwards compatibility only. 
add_metric
add_metric(
value, name=None, **kwargs
)
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 Input
s. 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
build(
input_shape
)
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

In each of these cases, the user should build their model by calling it on real tensor data. 
call
call(
inputs, training=False
)
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
call_get_leaves(
inputs
)
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 ith example and the jth 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
@staticmethod
capabilities() > abstract_learner_pb2.LearnerCapabilities
Lists the capabilities of the learning algorithm.
collect_data_step
collect_data_step(
data, is_training_example
)
Collect examples e.g. training or validation.
compile
compile(
metrics=None, weighted_metrics=None
)
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_loss(
x=None, y=None, y_pred=None, sample_weight=None
)
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
compute_mask(
inputs, mask=None
)
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
compute_metrics(
x, y, y_pred, sample_weight
)
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
compute_output_shape(
input_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_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
evaluate(
x=None,
y=None,
batch_size=None,
verbose='auto',
sample_weight=None,
steps=None,
callbacks=None,
max_queue_size=10,
workers=1,
use_multiprocessing=False,
return_dict=False,
**kwargs
)
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:

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 processbased
threading. If unspecified, workers will default to 1.

use_multiprocessing

Boolean. Used for generator or
keras.utils.Sequence input only. If True , use processbased
threading. If unspecified, use_multiprocessing will default to
False . Note that because this implementation relies on
multiprocessing, you should not pass nonpicklable 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 iteratorlike 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
fit(
x=None,
y=None,
callbacks=None,
verbose: Optional[Any] = None,
validation_steps: Optional[int] = None,
validation_data: Optional[Any] = None,
sample_weight: Optional[Any] = None,
steps_per_epoch: Optional[Any] = None,
class_weight: Optional[Any] = None,
**kwargs
) > tf.keras.callbacks.History
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:
"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.
"x" is a tensor, list of tensors or dictionary of tensors containing the input features. "y" is a tensor.
"x" is a numpyarray, list of numpyarrays or dictionary of numpyarrays containing the input features. "y" is a numpyarray.
 The dataset need to be read exactly once. If you use a TensorFlow dataset, make sure NOT to add a "repeat" operation.
 The algorithm does not benefit from shuffling the dataset. If you use a TensorFlow dataset, make sure NOT to add a "shuffle" operation.
 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 speedsup 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 nondistributed 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).
Here is a full example of distributed training:
def dataset_fn(context, paths, training=True): ds_path = tf.data.Dataset.from_tensor_slices(paths)
# 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 nonDistributed
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
fit_on_dataset_path(
train_path: str,
label_key: str,
weight_key: Optional[str] = None,
ranking_key: Optional[str] = None,
valid_path: Optional[str] = None,
dataset_format: Optional[str] = 'csv',
max_num_scanned_rows_to_accumulate_statistics: Optional[int] = 100000,
try_resume_training: Optional[bool] = True,
input_model_signature_fn: Optional[tf_core.InputModelSignatureFn] = tfdf.keras.build_default_input_model_signature
)
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/yggdrasildecisionforests/blob/main/documentation/user_manual.md#datasetpathandformat
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 outofvocabulary). 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 hyperparameter 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
@classmethod
from_config( config, custom_objects=None )
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
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
get_layer(
name=None, index=None
)
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 (bottomup).
Args  

name

String, name of layer. 
index

Integer, index of layer. 
Returns  

A layer instance. 
get_weights
get_weights()
Retrieves the weights of the model.
Returns  

A flat list of Numpy arrays. 
load_weights
load_weights(
*args, **kwargs
)
Noop 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
make_inspector() > tfdf.inspector.AbstractInspector
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
make_predict_function()
Prediction of the model (!= evaluation).
make_test_function
make_test_function()
Predictions for evaluation.
make_train_function
make_train_function(
force=False
)
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
@staticmethod
predefined_hyperparameters() > List[
tfdf.keras.core.HyperParameterTemplate
]
Returns a better than default set of hyperparameters.
They can be used directly with the hyperparameter_template
argument of the
model constructor.
These hyperparameters outperforms the default hyperparameters (either generally or in specific scenarios). Like default hyperparameters, existing predefined hyperparameters cannot change.
predict
predict(
x,
batch_size=None,
verbose='auto',
steps=None,
callbacks=None,
max_queue_size=10,
workers=1,
use_multiprocessing=False
)
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:

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
processbased threading. If unspecified, workers will default
to 1.

use_multiprocessing

Boolean. Used for generator or
keras.utils.Sequence input only. If True , use processbased
threading. If unspecified, use_multiprocessing will default to
False . Note that because this implementation relies on
multiprocessing, you should not pass nonpicklable arguments to
the generator as they can't be passed easily to children processes.

See the discussion of Unpacking behavior for iteratorlike 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
predict_get_leaves(
x
)
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 ith example and the jth 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
predict_on_batch(
x
)
Returns predictions for a single batch of samples.
Args  

x

Input data. It could be:

Returns  

Numpy array(s) of predictions. 
Raises  

RuntimeError

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

predict_step
predict_step(
data
)
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 Tensor s.

Returns  

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

reset_metrics
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
reset_states()
save
save(
filepath: str, overwrite: Optional[bool] = True, **kwargs
)
Saves the model as a TensorFlow SavedModel.
The exported SavedModel contains a standalone Yggdrasil Decision Forests model in the "assets" subdirectory. 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
save_spec(
dynamic_batch=True
)
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
save_weights(
filepath, overwrite=True, save_format=None, options=None
)
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
namedlayer.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.
 For every such layer group, a group attribute
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 userdefined 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
set_weights(
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
summary(
line_length=None, positions=None, print_fn=None
)
Shows information about the model.
test_on_batch
test_on_batch(
x, y=None, sample_weight=None, reset_metrics=True, return_dict=False
)
Test the model on a single batch of samples.
Args  

x

Input data. It could be:

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
test_step(
data
)
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 Tensor s.

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
to_json(
**kwargs
)
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
to_yaml(
**kwargs
)
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
train_on_batch(
x,
y=None,
sample_weight=None,
class_weight=None,
reset_metrics=True,
return_dict=False
)
Runs a single gradient update on a single batch of data.
Args  

x

Input data. It could be:

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 underrepresented 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
train_step(
data
)
Collects training examples.
valid_step
valid_step(
data
)
Collects validation examples.
with_name_scope
@classmethod
with_name_scope( method )
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.Variable
s and tf.Tensor
s 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
yggdrasil_model_path_tensor() > Optional[tf.Tensor]
Gets the path to yggdrasil model, if available.
The effective path can be obtained with:
yggdrasil_model_path_tensor().numpy().decode("utf8")
Returns  

Path to the Yggdrasil model. 
__call__
__call__(
*args, **kwargs
)