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Creates a _Head
for regression using the mean_squared_error
loss.
tf.contrib.estimator.regression_head(
weight_column=None, label_dimension=1,
loss_reduction=losses.Reduction.SUM_OVER_BATCH_SIZE, loss_fn=None,
inverse_link_fn=None, name=None
)
The loss is the weighted sum over all input dimensions. Namely, if the input
labels have shape [batch_size, label_dimension]
, the loss is the weighted
sum over both batch_size
and label_dimension
.
The head expects logits
with shape [D0, D1, ... DN, label_dimension]
.
In many applications, the shape is [batch_size, label_dimension]
.
The labels
shape must match logits
, namely
[D0, D1, ... DN, label_dimension]
. If label_dimension=1
, shape
[D0, D1, ... DN]
is also supported.
If weight_column
is specified, weights must be of shape
[D0, D1, ... DN]
, [D0, D1, ... DN, 1]
or
[D0, D1, ... DN, label_dimension]
.
Supports custom loss_fn
. loss_fn
takes (labels, logits)
or
(labels, logits, features)
as arguments and returns unreduced loss with
shape [D0, D1, ... DN, label_dimension]
.
Also supports custom inverse_link_fn
, also known as 'mean function'.
inverse_link_fn
is only used in PREDICT
mode. It takes logits
as
argument and returns predicted values. This function is the inverse of the
link function defined in
https://en.wikipedia.org/wiki/Generalized_linear_model#Link_function
Namely, for poisson regression, set inverse_link_fn=tf.exp
.
The head can be used with a canned estimator. Example:
my_head = tf.contrib.estimator.regression_head()
my_estimator = tf.estimator.DNNEstimator(
head=my_head,
hidden_units=...,
feature_columns=...)
It can also be used with a custom model_fn
. Example:
def _my_model_fn(features, labels, mode):
my_head = tf.contrib.estimator.regression_head()
logits = tf.keras.Model(...)(features)
return my_head.create_estimator_spec(
features=features,
mode=mode,
labels=labels,
optimizer=tf.AdagradOptimizer(learning_rate=0.1),
logits=logits)
my_estimator = tf.estimator.Estimator(model_fn=_my_model_fn)
Args | |
---|---|
weight_column
|
A string or a _NumericColumn created by
tf.feature_column.numeric_column defining feature column representing
weights. It is used to down weight or boost examples during training. It
will be multiplied by the loss of the example.
|
label_dimension
|
Number of regression labels per example. This is the size
of the last dimension of the labels Tensor (typically, this has shape
[batch_size, label_dimension] ).
|
loss_reduction
|
One of tf.losses.Reduction except NONE . Describes how to
reduce training loss over batch and label dimension. Defaults to
SUM_OVER_BATCH_SIZE , namely weighted sum of losses divided by
batch size * label_dimension . See tf.losses.Reduction .
|
loss_fn
|
Optional loss function. Defaults to mean_squared_error .
|
inverse_link_fn
|
Optional inverse link function, also known as 'mean function'. Defaults to identity. |
name
|
name of the head. If provided, summary and metrics keys will be
suffixed by "/" + name . Also used as name_scope when creating ops.
|
Returns | |
---|---|
An instance of _Head for linear regression.
|
Raises | |
---|---|
ValueError
|
If label_dimension or loss_reduction is invalid.
|