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tf.compat.v1.train.create_global_step

Create global step tensor in graph.

tf.compat.v1.train.create_global_step(
    graph=None
)

Migrate to TF2

Caution: This API was designed for TensorFlow v1. Continue reading for details on how to migrate from this API to a native TensorFlow v2 equivalent. See the TensorFlow v1 to TensorFlow v2 migration guide for instructions on how to migrate the rest of your code.

With the deprecation of global graphs, TF no longer tracks variables in collections. In other words, there are no global variables in TF2. Thus, the global step functions have been removed (get_or_create_global_step, create_global_step, get_global_step) . You have two options for migrating:

  1. Create a Keras optimizer, which generates an iterations variable. This variable is automatically incremented when calling apply_gradients.
  2. Manually create and increment a tf.Variable.

Below is an example of migrating away from using a global step to using a Keras optimizer:

Define a dummy model and loss:

def compute_loss(x):
  v = tf.Variable(3.0)
  y = x * v
  loss = x * 5 - x * v
  return loss, [v]

Before migrating:

g = tf.Graph()
with g.as_default():
  x = tf.compat.v1.placeholder(tf.float32, [])
  loss, var_list = compute_loss(x)
  global_step = tf.compat.v1.train.create_global_step()
  global_init = tf.compat.v1.global_variables_initializer()
  optimizer = tf.compat.v1.train.GradientDescentOptimizer(0.1)
  train_op = optimizer.minimize(loss, global_step, var_list)
sess = tf.compat.v1.Session(graph=g)
sess.run(global_init)
print("before training:", sess.run(global_step))
before training: 0
sess.run(train_op, feed_dict={x: 3})
print("after training:", sess.run(global_step))
after training: 1

Migrating to a Keras optimizer:

optimizer = tf.keras.optimizers.SGD(.01)
print("before training:", optimizer.iterations.numpy())
before training: 0
with tf.GradientTape() as tape:
  loss, var_list = compute_loss(3)
  grads = tape.gradient(loss, var_list)
  optimizer.apply_gradients(zip(grads, var_list))
print("after training:", optimizer.iterations.numpy())
after training: 1

Description

Args
graph The graph in which to create the global step tensor. If missing, use default graph.
Returns
Global step tensor.
Raises
ValueError if global step tensor is already defined.

© 2022 The TensorFlow Authors. All rights reserved.
Licensed under the Creative Commons Attribution License 4.0.
Code samples licensed under the Apache 2.0 License.
https://www.tensorflow.org/api_docs/python/tf/compat/v1/train/create_global_step

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