def _model_fn(features, labels, mode):
"""Model function."""
assert labels is None, labels
(all_scores, model_predictions, losses,
training_op) = clustering_ops.KMeans(
self._parse_tensor_or_dict(features),
self._num_clusters,
self._training_initial_clusters,
self._distance_metric,
self._use_mini_batch,
random_seed=self._random_seed,
kmeans_plus_plus_num_retries=self.
_kmeans_plus_plus_num_retries).training_graph()
incr_step = state_ops.assign_add(variables.get_global_step(), 1)
loss = math_ops.reduce_sum(losses, name=KMeansClustering.LOSS_OP_NAME)
logging_ops.scalar_summary('loss/raw', loss)
training_op = with_dependencies([training_op, incr_step], loss)
predictions = {
KMeansClustering.ALL_SCORES: all_scores[0],
KMeansClustering.CLUSTER_IDX: model_predictions[0],
}
eval_metric_ops = {KMeansClustering.SCORES: loss,}
return ModelFnOps(
mode=mode,
predictions=predictions,
eval_metric_ops=eval_metric_ops,
loss=loss,
train_op=training_op)
def inference(inp, num_clusters, hidden1_units, hidden2_units):
"""Build the MNIST model up to where it may be used for inference.
Args:
inp: input data
num_clusters: number of clusters of input features to train.
hidden1_units: Size of the first hidden layer.
hidden2_units: Size of the second hidden layer.
Returns:
logits: Output tensor with the computed logits.
clustering_loss: Clustering loss.
kmeans_training_op: An op to train the clustering.
"""
# Clustering
kmeans = clustering_ops.KMeans(
inp,
num_clusters,
distance_metric=clustering_ops.COSINE_DISTANCE,
# TODO(agarwal): kmeans++ is currently causing crash in dbg mode.
# Enable this after fixing.
# initial_clusters=clustering_ops.KMEANS_PLUS_PLUS_INIT,
use_mini_batch=True)
all_scores, _, clustering_scores, kmeans_training_op = kmeans.training_graph(
)
# Some heuristics to approximately whiten this output.
all_scores = (all_scores[0] - 0.5) * 5
# Here we avoid passing the gradients from the supervised objective back to
# the clusters by creating a stop_gradient node.
all_scores = tf.stop_gradient(all_scores)
clustering_loss = tf.reduce_sum(clustering_scores[0])
# Hidden 1
with tf.name_scope('hidden1'):
weights = tf.Variable(tf.truncated_normal(
[num_clusters, hidden1_units],
stddev=1.0 / math.sqrt(float(IMAGE_PIXELS))),
name='weights')
biases = tf.Variable(tf.zeros([hidden1_units]), name='biases')
hidden1 = tf.nn.relu(tf.matmul(all_scores, weights) + biases)
# Hidden 2
with tf.name_scope('hidden2'):
weights = tf.Variable(tf.truncated_normal(
[hidden1_units, hidden2_units],
stddev=1.0 / math.sqrt(float(hidden1_units))),
name='weights')
biases = tf.Variable(tf.zeros([hidden2_units]), name='biases')
hidden2 = tf.nn.relu(tf.matmul(hidden1, weights) + biases)
# Linear
with tf.name_scope('softmax_linear'):
weights = tf.Variable(tf.truncated_normal(
[hidden2_units, NUM_CLASSES],
stddev=1.0 / math.sqrt(float(hidden2_units))),
name='weights')
biases = tf.Variable(tf.zeros([NUM_CLASSES]), name='biases')
logits = tf.matmul(hidden2, weights) + biases
return logits, clustering_loss, kmeans_training_op
def kmeans_cluster_model_fn(features, labels, mode, params, config):
"""Model function for KMeansClustering estimator."""
# https://wiki.python.org/moin/UsingAssertionsEffectively
assert labels is None, "labels are not needed: " + labels
# clustering_ops.KMeans 是重要的算法实现过程
# https://github.com/tensorflow/tensorflow/blob/master/tensorflow
# /contrib/factorization/python/ops/clustering_ops.py
(all_scores, model_predictions, losses,
is_initialized, cluster_centers_var, init_op, training_op) = \
clustering_ops.KMeans(
_parse_tensor_or_dict(features),
params.get('num_clusters'),
initial_clusters=clustering_ops.RANDOM_INIT,
distance_metric=clustering_ops.SQUARED_EUCLIDEAN_DISTANCE,
use_mini_batch=False,
mini_batch_steps_per_iteration=1,
# use_mini_batch = params.get('use_mini_batch'),
# mini_batch_steps_per_iteration=params.get(
# 'mini_batch_steps_per_iteration'),
random_seed=params.get('random_seed'),
kmeans_plus_plus_num_retries=params.get(
'kmeans_plus_plus_num_retries')).training_graph()
incr_step = state_ops.assign_add(variables.get_global_step(), 1)
loss = math_ops.reduce_sum(losses, name='kmeans_loss')
# Outputs a Summary protocol buffer containing a single scalar value.
# Used for visualizing in TensorBoard
summary.scalar('loss/raw', loss)
# https://github.com/tensorflow/tensorflow/blob/master/tensorflow
# /python/ops/control_flow_ops.py
# with_dependencies(dependencies, output_tensor, name=None):
# Produces the content of `output_tensor` only after `dependencies`.
training_op = with_dependencies([training_op, incr_step], loss)
predictions = {
'all_scores': all_scores[0],
'cluster_idx': model_predictions[0],
}
eval_metric_ops = {'scores': loss}
# Hook for monitor
training_hooks = [
_InitializeClustersHook(init_op, is_initialized, config.is_chief)
]
relative_tolerance = params.get('relative_tolerance')
if relative_tolerance is not None:
training_hooks.append(_LossRelativeChangeHook(relative_tolerance))
return ModelFnOps(mode=mode,
predictions=predictions,
eval_metric_ops=eval_metric_ops,
loss=loss,
train_op=training_op,
training_hooks=training_hooks)
def _get_eval_ops(self, features, _, unused_metrics):
(_, _, losses, _) = clustering_ops.KMeans(
features,
self._num_clusters,
self._training_initial_clusters,
self._distance_metric,
self._use_mini_batch,
random_seed=self._random_seed,
kmeans_plus_plus_num_retries=self.kmeans_plus_plus_num_retries
).training_graph()
return {
KMeansClustering.SCORES: tf.reduce_sum(losses),
}
def _get_predict_ops(self, features):
(all_scores, model_predictions, _, _) = clustering_ops.KMeans(
features,
self._num_clusters,
self._training_initial_clusters,
self._distance_metric,
self._use_mini_batch,
random_seed=self._random_seed,
kmeans_plus_plus_num_retries=self.kmeans_plus_plus_num_retries
).training_graph()
return {
KMeansClustering.ALL_SCORES: all_scores[0],
KMeansClustering.CLUSTER_IDX: model_predictions[0]
}
def _get_train_ops(self, features, _):
(_, _, losses, training_op) = clustering_ops.KMeans(
features,
self._num_clusters,
self._training_initial_clusters,
self._distance_metric,
self._use_mini_batch,
random_seed=self._random_seed,
kmeans_plus_plus_num_retries=self.kmeans_plus_plus_num_retries
).training_graph()
incr_step = tf.assign_add(tf.contrib.framework.get_global_step(), 1)
self._loss = tf.reduce_sum(losses)
training_op = with_dependencies([training_op, incr_step], self._loss)
return training_op, self._loss
def _build_estimator(self, X=None):
if not self._estimator_built:
if self.num_features is None:
self.num_features = get_num_features(X)
# Reload params from checkpoint if available
if self._to_be_restored and self.num_features is None:
self.num_features = read_tensor_in_checkpoint(
'num_features', self._to_be_restored)
if self._to_be_restored and self.num_classes is None:
self.num_classes = read_tensor_in_checkpoint(
'num_classes', self._to_be_restored)
# Purity checks
if self.num_features is None:
raise ValueError("'num_features' cannot be None.")
# Persistent Parameters
tf.Variable(self.num_features, dtype=tf.int32, name='num_features')
self._kmeans = c_ops.KMeans(X,
self.n_clusters,
initial_clusters=self.init,
distance_metric=self.distance,
use_mini_batch=self.use_mini_batch)
(self._all_scores, self._cluster_idx, self._scores,
self._cluster_centers_initialized, self._cluster_centers_vars,
self._init_op, self._train_op) = self._kmeans.training_graph()
# fix for cluster_idx being a tuple
self._cluster_idx = self._cluster_idx[0]
self.avg_distance = tf.reduce_mean(self._scores)
self._estimator_built = True
self._init_graph()
def _kmeans_clustering_model_fn(features, labels, mode, params, config):
"""Model function for KMeansClustering estimator."""
assert labels is None, labels
(all_scores, model_predictions, losses, is_initialized, init_op,
training_op) = clustering_ops.KMeans(
_parse_tensor_or_dict(features),
params.get('num_clusters'),
initial_clusters=params.get('training_initial_clusters'),
distance_metric=params.get('distance_metric'),
use_mini_batch=params.get('use_mini_batch'),
mini_batch_steps_per_iteration=params.get(
'mini_batch_steps_per_iteration'),
random_seed=params.get('random_seed'),
kmeans_plus_plus_num_retries=params.get(
'kmeans_plus_plus_num_retries')).training_graph()
incr_step = state_ops.assign_add(variables.get_global_step(), 1)
loss = math_ops.reduce_sum(losses, name=KMeansClustering.LOSS_OP_NAME)
summary.scalar('loss/raw', loss)
training_op = with_dependencies([training_op, incr_step], loss)
predictions = {
KMeansClustering.ALL_SCORES: all_scores[0],
KMeansClustering.CLUSTER_IDX: model_predictions[0],
}
eval_metric_ops = {KMeansClustering.SCORES: loss}
training_hooks = [
_InitializeClustersHook(init_op, is_initialized, config.is_chief)
]
relative_tolerance = params.get('relative_tolerance')
if relative_tolerance is not None:
training_hooks.append(_LossRelativeChangeHook(relative_tolerance))
return ModelFnOps(mode=mode,
predictions=predictions,
eval_metric_ops=eval_metric_ops,
loss=loss,
train_op=training_op,
training_hooks=training_hooks)
def model_fn(self, features, mode, config):
"""Model function for the estimator.
Note that this does not take a `labels` arg. This works, but `input_fn` must
return either `features` or, equivalently, `(features, None)`.
Args:
features: The input points. See `tf.estimator.Estimator`.
mode: See `tf.estimator.Estimator`.
config: See `tf.estimator.Estimator`.
Returns:
A `tf.estimator.EstimatorSpec` (see `tf.estimator.Estimator`) specifying
this behavior:
* `train_op`: Execute one mini-batch or full-batch run of Lloyd's
algorithm.
* `loss`: The sum of the squared distances from each input point to its
closest center.
* `eval_metric_ops`: Maps `SCORE` to `loss`.
* `predictions`: Maps `ALL_DISTANCES` to the distance from each input
point to each cluster center; maps `CLUSTER_INDEX` to the index of
the closest cluster center for each input point.
"""
# input_points is a single Tensor. Therefore, the sharding functionality
# in clustering_ops is unused, and some of the values below are lists of a
# single item.
input_points = _parse_features_if_necessary(features,
self._feature_columns)
# Let N = the number of input_points.
# all_distances: A list of one matrix of shape (N, num_clusters). Each value
# is the distance from an input point to a cluster center.
# model_predictions: A list of one vector of shape (N). Each value is the
# cluster id of an input point.
# losses: Similar to cluster_idx but provides the distance to the cluster
# center.
# is_initialized: scalar indicating whether the initial cluster centers
# have been chosen; see init_op.
# init_op: an op to choose the initial cluster centers. A single worker
# repeatedly executes init_op until is_initialized becomes True.
# training_op: an op that runs an iteration of training, either an entire
# Lloyd iteration or a mini-batch of a Lloyd iteration. Multiple workers
# may execute this op, but only after is_initialized becomes True.
(all_distances, model_predictions, losses, is_initialized, init_op,
training_op) = clustering_ops.KMeans(
inputs=input_points,
num_clusters=self._num_clusters,
initial_clusters=self._initial_clusters,
distance_metric=self._distance_metric,
use_mini_batch=self._use_mini_batch,
mini_batch_steps_per_iteration=self.
_mini_batch_steps_per_iteration,
random_seed=self._random_seed,
kmeans_plus_plus_num_retries=self._kmeans_plus_plus_num_retries
).training_graph()
loss = math_ops.reduce_sum(losses)
summary.scalar('loss/raw', loss)
incr_step = state_ops.assign_add(training_util.get_global_step(), 1)
training_op = control_flow_ops.with_dependencies(
[training_op, incr_step], loss)
training_hooks = [
_InitializeClustersHook(init_op, is_initialized, config.is_chief)
]
if self._relative_tolerance is not None:
training_hooks.append(
_LossRelativeChangeHook(loss, self._relative_tolerance))
export_outputs = {
KMeansClustering.ALL_DISTANCES:
export_output.PredictOutput(all_distances[0]),
KMeansClustering.CLUSTER_INDEX:
export_output.PredictOutput(model_predictions[0]),
signature_constants.DEFAULT_SERVING_SIGNATURE_DEF_KEY:
export_output.PredictOutput(model_predictions[0])
}
return model_fn_lib.EstimatorSpec(
mode=mode,
predictions={
KMeansClustering.ALL_DISTANCES: all_distances[0],
KMeansClustering.CLUSTER_INDEX: model_predictions[0],
},
loss=loss,
train_op=training_op,
eval_metric_ops={KMeansClustering.SCORE: metrics.mean(loss)},
training_hooks=training_hooks,
export_outputs=export_outputs)