def _get_default_head(params, weights_name, output_type, name=None):
"""Creates a default head based on a type of a problem."""
if output_type == ModelBuilderOutputType.MODEL_FN_OPS:
if params.regression:
return head_lib.regression_head(weight_column_name=weights_name,
label_dimension=params.num_outputs,
enable_centered_bias=False,
head_name=name)
else:
return head_lib.multi_class_head(params.num_classes,
weight_column_name=weights_name,
enable_centered_bias=False,
head_name=name)
else:
if params.regression:
return core_head_lib.regression_head(
weight_column=weights_name,
label_dimension=params.num_outputs,
name=name,
loss_reduction=losses.Reduction.SUM_OVER_BATCH_SIZE)
else:
if params.num_classes == 2:
return core_head_lib.binary_classification_head(
weight_column=weights_name,
name=name,
loss_reduction=losses.Reduction.SUM_OVER_BATCH_SIZE)
else:
return core_head_lib.multi_class_head(
n_classes=params.num_classes,
weight_column=weights_name,
name=name,
loss_reduction=losses.Reduction.SUM_OVER_BATCH_SIZE)
def testJointLinearModel(self):
"""Tests that loss goes down with training."""
def input_fn():
return {
'age':
sparse_tensor.SparseTensor(values=['1'],
indices=[[0, 0]],
dense_shape=[1, 1]),
'language':
sparse_tensor.SparseTensor(values=['english'],
indices=[[0, 0]],
dense_shape=[1, 1])
}, constant_op.constant([[1]])
language = feature_column.sparse_column_with_hash_bucket(
'language', 100)
age = feature_column.sparse_column_with_hash_bucket('age', 2)
head = head_lib.multi_class_head(n_classes=2)
classifier = _joint_linear_estimator(head,
feature_columns=[age, language])
classifier.fit(input_fn=input_fn, steps=1000)
loss1 = classifier.evaluate(input_fn=input_fn, steps=1)['loss']
classifier.fit(input_fn=input_fn, steps=2000)
loss2 = classifier.evaluate(input_fn=input_fn, steps=1)['loss']
self.assertLess(loss2, loss1)
self.assertLess(loss2, 0.01)
def __init__(self,
example_id_column,
feature_columns,
weight_column_name=None,
model_dir=None,
l1_regularization=0.0,
l2_regularization=1.0,
num_loss_partitions=None,
config=None,
feature_engineering_fn=None,
partitioner=None):
"""Construct a `SDCALogisticClassifier` object.
Args:
example_id_column: A string defining the feature column name representing
example ids. Used to initialize the underlying SDCA optimizer.
feature_columns: An iterable containing all the feature columns used by
the model. All items in the iterable should derive from `FeatureColumn`.
Note that the order of the items is ignored at model construction time.
weight_column_name: A string defining feature column name representing
weights. It is used to downweight or boost examples during training. It
will be multiplied by the loss of the example.
model_dir: Directory to save model parameters, graph etc. This can also be
used to load checkpoints from the directory into an estimator to
continue training a previously saved model.
l1_regularization: L1-regularization parameter. Refers to global L1
regularization (across all examples).
l2_regularization: L2-regularization parameter. Refers to global L2
regularization (across all examples).
num_loss_partitions: Number of partitions of the global loss function
optimized by the underlying optimizer (SDCAOptimizer).
config: `RunConfig` object to configure the runtime settings.
feature_engineering_fn: Feature engineering function. Takes features and
labels which are the output of `input_fn` and returns features and
labels which will be fed into the model.
partitioner: Variable partitioner for the primal weights (`div`
partitioning strategy will be used).
Returns:
A `SDCALogisiticClassifier` estimator.
"""
super(SDCALogisticClassifier,
self).__init__(example_id_column=example_id_column,
feature_columns=feature_columns,
weight_column_name=weight_column_name,
model_dir=model_dir,
head=head_lib.multi_class_head(
n_classes=2,
weight_column_name=weight_column_name),
l1_regularization=l1_regularization,
l2_regularization=l2_regularization,
num_loss_partitions=num_loss_partitions,
config=config,
feature_engineering_fn=None,
partitioner=partitioner)
def __init__(self,
feature_columns=None,
model_dir=None,
n_classes=2,
weight_column_name=None,
optimizer=None,
kernel_mappers=None,
config=None):
"""Construct a `KernelLinearClassifier` estimator object.
Args:
feature_columns: An iterable containing all the feature columns used by
the model. All items in the set should be instances of classes derived
from `FeatureColumn`.
model_dir: Directory to save model parameters, graph etc. This can also be
used to load checkpoints from the directory into an estimator to
continue training a previously saved model.
n_classes: number of label classes. Default is binary classification.
Note that class labels are integers representing the class index (i.e.
values from 0 to n_classes-1). For arbitrary label values (e.g. string
labels), convert to class indices first.
weight_column_name: A string defining feature column name representing
weights. It is used to down weight or boost examples during training. It
will be multiplied by the loss of the example.
optimizer: The optimizer used to train the model. If specified, it should
be an instance of `tf.Optimizer`. If `None`, the Ftrl optimizer is used
by default.
kernel_mappers: Dictionary of kernel mappers to be applied to the input
features before training a (linear) model. Keys are feature columns and
values are lists of mappers to be applied to the corresponding feature
column. Currently only _RealValuedColumns are supported and therefore
all mappers should conform to the `DenseKernelMapper` interface (see
./mappers/dense_kernel_mapper.py).
config: `RunConfig` object to configure the runtime settings.
Returns:
A `KernelLinearClassifier` estimator.
Raises:
ValueError: if n_classes < 2.
ValueError: if neither feature_columns nor kernel_mappers are provided.
ValueError: if mappers provided as kernel_mappers values are invalid.
"""
super(KernelLinearClassifier,
self).__init__(feature_columns=feature_columns,
model_dir=model_dir,
weight_column_name=weight_column_name,
head=head_lib.multi_class_head(
n_classes=n_classes,
weight_column_name=weight_column_name),
optimizer=optimizer,
kernel_mappers=kernel_mappers,
config=config)
def testDNNModel(self):
"""Tests multi-class classification using matrix data as input."""
cont_features = [
feature_column.real_valued_column('feature', dimension=4)
]
head = head_lib.multi_class_head(n_classes=3)
classifier = _dnn_estimator(head,
feature_columns=cont_features,
hidden_units=[3, 3])
classifier.fit(input_fn=_iris_input_fn, steps=1000)
classifier.evaluate(input_fn=_iris_input_fn, steps=100)
def __init__(self,
model_dir=None,
n_classes=2,
weight_column_name=None,
config=None,
feature_engineering_fn=None,
label_keys=None):
"""Initializes a DebugClassifier instance.
Args:
model_dir: Directory to save model parameters, graph and etc. This can
also be used to load checkpoints from the directory into a estimator to
continue training a previously saved model.
n_classes: number of label classes. Default is binary classification.
It must be greater than 1. Note: Class labels are integers representing
the class index (i.e. values from 0 to n_classes-1). For arbitrary
label values (e.g. string labels), convert to class indices first.
weight_column_name: A string defining feature column name representing
weights. It is used to down weight or boost examples during training. It
will be multiplied by the loss of the example.
config: `RunConfig` object to configure the runtime settings.
feature_engineering_fn: Feature engineering function. Takes features and
labels which are the output of `input_fn` and returns
features and labels which will be fed into the model.
label_keys: Optional list of strings with size `[n_classes]` defining the
label vocabulary. Only supported for `n_classes` > 2.
Returns:
A `DebugClassifier` estimator.
Raises:
ValueError: If `n_classes` < 2.
"""
params = {
"head":
head_lib.multi_class_head(n_classes=n_classes,
weight_column_name=weight_column_name,
enable_centered_bias=True,
label_keys=label_keys)
}
super(DebugClassifier,
self).__init__(model_fn=debug_model_fn,
model_dir=model_dir,
config=config,
params=params,
feature_engineering_fn=feature_engineering_fn)
def __init__(self,
dnn_hidden_units,
dnn_feature_columns,
tree_learner_config,
num_trees,
tree_examples_per_layer,
n_classes=2,
weight_column_name=None,
model_dir=None,
config=None,
label_name=None,
label_keys=None,
feature_engineering_fn=None,
dnn_optimizer="Adagrad",
dnn_activation_fn=nn.relu,
dnn_dropout=None,
dnn_input_layer_partitioner=None,
dnn_input_layer_to_tree=True,
dnn_steps_to_train=10000,
predict_with_tree_only=False,
tree_feature_columns=None,
tree_center_bias=False,
dnn_to_tree_distillation_param=None,
use_core_versions=False,
override_global_step_value=None):
"""Initializes a DNNBoostedTreeCombinedClassifier instance.
Args:
dnn_hidden_units: List of hidden units per layer for DNN.
dnn_feature_columns: An iterable containing all the feature columns
used by the model's DNN.
tree_learner_config: A config for the tree learner.
num_trees: Number of trees to grow model to after training DNN.
tree_examples_per_layer: Number of examples to accumulate before
growing the tree a layer. This value has a big impact on model
quality and should be set equal to the number of examples in
training dataset if possible. It can also be a function that computes
the number of examples based on the depth of the layer that's
being built.
n_classes: The number of label classes.
weight_column_name: The name of weight column.
model_dir: Directory for model exports.
config: `RunConfig` of the estimator.
label_name: String, name of the key in label dict. Can be null if label
is a tensor (single headed models).
label_keys: Optional list of strings with size `[n_classes]` defining the
label vocabulary. Only supported for `n_classes` > 2.
feature_engineering_fn: Feature engineering function. Takes features and
labels which are the output of `input_fn` and returns features and
labels which will be fed into the model.
dnn_optimizer: string, `Optimizer` object, or callable that defines the
optimizer to use for training the DNN. If `None`, will use the Adagrad
optimizer with default learning rate.
dnn_activation_fn: Activation function applied to each layer of the DNN.
If `None`, will use `tf.nn.relu`.
dnn_dropout: When not `None`, the probability to drop out a given
unit in the DNN.
dnn_input_layer_partitioner: Partitioner for input layer of the DNN.
Defaults to `min_max_variable_partitioner` with `min_slice_size`
64 << 20.
dnn_input_layer_to_tree: Whether to provide the DNN's input layer
as a feature to the tree.
dnn_steps_to_train: Number of steps to train dnn for before switching
to gbdt.
predict_with_tree_only: Whether to use only the tree model output as the
final prediction.
tree_feature_columns: An iterable containing all the feature columns
used by the model's boosted trees. If dnn_input_layer_to_tree is
set to True, these features are in addition to dnn_feature_columns.
tree_center_bias: Whether a separate tree should be created for
first fitting the bias.
dnn_to_tree_distillation_param: A Tuple of (float, loss_fn), where the
float defines the weight of the distillation loss, and the loss_fn, for
computing distillation loss, takes dnn_logits, tree_logits and weight
tensor. If the entire tuple is None, no distillation will be applied. If
only the loss_fn is None, we will take the sigmoid/softmax cross entropy
loss be default. When distillation is applied, `predict_with_tree_only`
will be set to True.
use_core_versions: Whether feature columns and loss are from the core (as
opposed to contrib) version of tensorflow.
override_global_step_value: If after the training is done, global step
value must be reset to this value. This is particularly useful for hyper
parameter tuning, which can't recognize early stopping due to the number
of trees. If None, no override of global step will happen.
"""
head = head_lib.multi_class_head(n_classes=n_classes,
label_name=label_name,
label_keys=label_keys,
weight_column_name=weight_column_name,
enable_centered_bias=False)
def _model_fn(features, labels, mode, config):
return _dnn_tree_combined_model_fn(
features=features,
labels=labels,
mode=mode,
head=head,
dnn_hidden_units=dnn_hidden_units,
dnn_feature_columns=dnn_feature_columns,
tree_learner_config=tree_learner_config,
num_trees=num_trees,
tree_examples_per_layer=tree_examples_per_layer,
config=config,
dnn_optimizer=dnn_optimizer,
dnn_activation_fn=dnn_activation_fn,
dnn_dropout=dnn_dropout,
dnn_input_layer_partitioner=dnn_input_layer_partitioner,
dnn_input_layer_to_tree=dnn_input_layer_to_tree,
dnn_steps_to_train=dnn_steps_to_train,
predict_with_tree_only=predict_with_tree_only,
tree_feature_columns=tree_feature_columns,
tree_center_bias=tree_center_bias,
dnn_to_tree_distillation_param=dnn_to_tree_distillation_param,
use_core_versions=use_core_versions,
override_global_step_value=override_global_step_value)
super(DNNBoostedTreeCombinedClassifier,
self).__init__(model_fn=_model_fn,
model_dir=model_dir,
config=config,
feature_engineering_fn=feature_engineering_fn)
def __init__(self,
learner_config,
examples_per_layer,
n_classes=2,
num_trees=None,
feature_columns=None,
weight_column_name=None,
model_dir=None,
config=None,
label_keys=None,
feature_engineering_fn=None,
logits_modifier_function=None,
center_bias=True,
use_core_libs=False,
output_leaf_index=False,
override_global_step_value=None,
num_quantiles=100):
"""Initializes a GradientBoostedDecisionTreeClassifier estimator instance.
Args:
learner_config: A config for the learner.
examples_per_layer: Number of examples to accumulate before growing a
layer. It can also be a function that computes the number of examples
based on the depth of the layer that's being built.
n_classes: Number of classes in the classification.
num_trees: An int, number of trees to build.
feature_columns: A list of feature columns.
weight_column_name: Name of the column for weights, or None if not
weighted.
model_dir: Directory for model exports, etc.
config: `RunConfig` object to configure the runtime settings.
label_keys: Optional list of strings with size `[n_classes]` defining the
label vocabulary. Only supported for `n_classes` > 2.
feature_engineering_fn: Feature engineering function. Takes features and
labels which are the output of `input_fn` and returns features and
labels which will be fed into the model.
logits_modifier_function: A modifier function for the logits.
center_bias: Whether a separate tree should be created for first fitting
the bias.
use_core_libs: Whether feature columns and loss are from the core (as
opposed to contrib) version of tensorflow.
output_leaf_index: whether to output leaf indices along with predictions
during inference. The leaf node indexes are available in predictions
dict by the key 'leaf_index'. It is a Tensor of rank 2 and its shape is
[batch_size, num_trees]. For example, result_iter =
classifier.predict(...)
for result_dict in result_iter: # access leaf index list by
result_dict["leaf_index"] # which contains one leaf index per tree
override_global_step_value: If after the training is done, global step
value must be reset to this value. This should be used to reset global
step to a number > number of steps used to train the current ensemble.
For example, the usual way is to train a number of trees and set a very
large number of training steps. When the training is done (number of
trees were trained), this parameter can be used to set the global step
to a large value, making it look like that number of training steps ran.
If None, no override of global step will happen.
num_quantiles: Number of quantiles to build for numeric feature values.
Raises:
ValueError: If learner_config is not valid.
"""
if n_classes > 2:
# For multi-class classification, use our loss implementation that
# supports second order derivative.
def loss_fn(labels, logits, weights=None):
result = losses.per_example_maxent_loss(labels=labels,
logits=logits,
weights=weights,
num_classes=n_classes)
return math_ops.reduce_mean(result[0])
else:
loss_fn = None
head = head_lib.multi_class_head(n_classes=n_classes,
weight_column_name=weight_column_name,
enable_centered_bias=False,
loss_fn=loss_fn,
label_keys=label_keys)
if learner_config.num_classes == 0:
learner_config.num_classes = n_classes
elif learner_config.num_classes != n_classes:
raise ValueError(
"n_classes (%d) doesn't match learner_config (%d)." %
(n_classes, learner_config.num_classes))
super(GradientBoostedDecisionTreeClassifier,
self).__init__(model_fn=model.model_builder,
params={
'head': head,
'feature_columns': feature_columns,
'learner_config': learner_config,
'num_trees': num_trees,
'weight_column_name': weight_column_name,
'examples_per_layer': examples_per_layer,
'center_bias': center_bias,
'logits_modifier_function':
logits_modifier_function,
'use_core_libs': use_core_libs,
'output_leaf_index': output_leaf_index,
'override_global_step_value':
override_global_step_value,
'num_quantiles': num_quantiles,
},
model_dir=model_dir,
config=config,
feature_engineering_fn=feature_engineering_fn)
def __init__(self,
hidden_units,
feature_columns,
model_dir=None,
n_classes=2,
weight_column_name=None,
optimizer=None,
activation_fn=nn.relu,
dropout=None,
gradient_clip_norm=None,
enable_centered_bias=False,
config=None,
feature_engineering_fn=None,
embedding_lr_multipliers=None,
input_layer_min_slice_size=None,
label_keys=None):
"""Initializes a DNNClassifier instance.
Args:
hidden_units: List of hidden units per layer. All layers are fully
connected. Ex. `[64, 32]` means first layer has 64 nodes and second one
has 32.
feature_columns: An iterable containing all the feature columns used by
the model. All items in the set should be instances of classes derived
from `FeatureColumn`.
model_dir: Directory to save model parameters, graph and etc. This can
also be used to load checkpoints from the directory into a estimator to
continue training a previously saved model.
n_classes: number of label classes. Default is binary classification.
It must be greater than 1. Note: Class labels are integers representing
the class index (i.e. values from 0 to n_classes-1). For arbitrary
label values (e.g. string labels), convert to class indices first.
weight_column_name: A string defining feature column name representing
weights. It is used to down weight or boost examples during training. It
will be multiplied by the loss of the example.
optimizer: An instance of `tf.Optimizer` used to train the model. If
`None`, will use an Adagrad optimizer.
activation_fn: Activation function applied to each layer. If `None`, will
use tf.nn.relu. Note that a string containing the unqualified
name of the op may also be provided, e.g., "relu", "tanh", or "sigmoid".
dropout: When not `None`, the probability we will drop out a given
coordinate.
gradient_clip_norm: A float > 0. If provided, gradients are
clipped to their global norm with this clipping ratio. See
`tf.clip_by_global_norm` for more details.
enable_centered_bias: A bool. If True, estimator will learn a centered
bias variable for each class. Rest of the model structure learns the
residual after centered bias.
config: `RunConfig` object to configure the runtime settings.
feature_engineering_fn: Feature engineering function. Takes features and
labels which are the output of `input_fn` and returns features and
labels which will be fed into the model.
embedding_lr_multipliers: Optional. A dictionary from `EmbeddingColumn` to
a `float` multiplier. Multiplier will be used to multiply with learning
rate for the embedding variables.
input_layer_min_slice_size: Optional. The min slice size of input layer
partitions. If not provided, will use the default of 64M.
label_keys: Optional list of strings with size `[n_classes]` defining the
label vocabulary. Only supported for `n_classes` > 2.
Returns:
A `DNNClassifier` estimator.
Raises:
ValueError: If `n_classes` < 2.
"""
self._feature_columns = tuple(feature_columns or [])
super(DNNClassifier,
self).__init__(model_fn=_dnn_model_fn,
model_dir=model_dir,
config=config,
params={
"head":
head_lib.multi_class_head(
n_classes,
weight_column_name=weight_column_name,
enable_centered_bias=enable_centered_bias,
label_keys=label_keys),
"hidden_units":
hidden_units,
"feature_columns":
self._feature_columns,
"optimizer":
optimizer,
"activation_fn":
activation_fn,
"dropout":
dropout,
"gradient_clip_norm":
gradient_clip_norm,
"embedding_lr_multipliers":
embedding_lr_multipliers,
"input_layer_min_slice_size":
input_layer_min_slice_size,
},
feature_engineering_fn=feature_engineering_fn)
def __init__(
self, # _joint_weight pylint: disable=invalid-name
feature_columns,
model_dir=None,
n_classes=2,
weight_column_name=None,
optimizer=None,
gradient_clip_norm=None,
enable_centered_bias=False,
_joint_weight=False,
config=None,
feature_engineering_fn=None,
label_keys=None):
"""Construct a `LinearClassifier` estimator object.
Args:
feature_columns: An iterable containing all the feature columns used by
the model. All items in the set should be instances of classes derived
from `FeatureColumn`.
model_dir: Directory to save model parameters, graph and etc. This can
also be used to load checkpoints from the directory into a estimator
to continue training a previously saved model.
n_classes: number of label classes. Default is binary classification.
Note that class labels are integers representing the class index (i.e.
values from 0 to n_classes-1). For arbitrary label values (e.g. string
labels), convert to class indices first.
weight_column_name: A string defining feature column name representing
weights. It is used to down weight or boost examples during training. It
will be multiplied by the loss of the example.
optimizer: The optimizer used to train the model. If specified, it should
be either an instance of `tf.Optimizer` or the SDCAOptimizer. If `None`,
the Ftrl optimizer will be used.
gradient_clip_norm: A `float` > 0. If provided, gradients are clipped
to their global norm with this clipping ratio. See
`tf.clip_by_global_norm` for more details.
enable_centered_bias: A bool. If True, estimator will learn a centered
bias variable for each class. Rest of the model structure learns the
residual after centered bias.
_joint_weight: If True, the weights for all columns will be stored in a
single (possibly partitioned) variable. It's more efficient, but it's
incompatible with SDCAOptimizer, and requires all feature columns are
sparse and use the 'sum' combiner.
config: `RunConfig` object to configure the runtime settings.
feature_engineering_fn: Feature engineering function. Takes features and
labels which are the output of `input_fn` and
returns features and labels which will be fed
into the model.
label_keys: Optional list of strings with size `[n_classes]` defining the
label vocabulary. Only supported for `n_classes` > 2.
Returns:
A `LinearClassifier` estimator.
Raises:
ValueError: if n_classes < 2.
ValueError: if enable_centered_bias=True and optimizer is SDCAOptimizer.
"""
if (isinstance(optimizer, sdca_optimizer.SDCAOptimizer)
and enable_centered_bias):
raise ValueError("enable_centered_bias is not supported with SDCA")
self._feature_columns = tuple(feature_columns or [])
assert self._feature_columns
chief_hook = None
head = head_lib.multi_class_head(
n_classes,
weight_column_name=weight_column_name,
enable_centered_bias=enable_centered_bias,
label_keys=label_keys)
params = {
"head": head,
"feature_columns": feature_columns,
"optimizer": optimizer,
}
if isinstance(optimizer, sdca_optimizer.SDCAOptimizer):
assert not _joint_weight, ("_joint_weight is incompatible with the"
" SDCAOptimizer")
assert n_classes == 2, "SDCA only applies to binary classification."
model_fn = sdca_model_fn
# The model_fn passes the model parameters to the chief_hook. We then use
# the hook to update weights and shrink step only on the chief.
chief_hook = _SdcaUpdateWeightsHook()
params.update({
"weight_column_name": weight_column_name,
"update_weights_hook": chief_hook,
})
else:
model_fn = _linear_model_fn
params.update({
"gradient_clip_norm": gradient_clip_norm,
"joint_weights": _joint_weight,
})
super(LinearClassifier,
self).__init__(model_fn=model_fn,
model_dir=model_dir,
config=config,
params=params,
feature_engineering_fn=feature_engineering_fn)