tf.train.init_from_checkpoint
Replaces tf.Variable
initializers so they load from a checkpoint file.
tf.train.init_from_checkpoint( ckpt_dir_or_file, assignment_map )
Values are not loaded immediately, but when the initializer is run (typically by running a tf.compat.v1.global_variables_initializer
op).
Note: This overrides default initialization ops of specified variables and redefines dtype.
Assignment map supports following syntax:
-
'checkpoint_scope_name/': 'scope_name/'
- will load all variables in currentscope_name
fromcheckpoint_scope_name
with matching tensor names. -
'checkpoint_scope_name/some_other_variable': 'scope_name/variable_name'
- will initializescope_name/variable_name
variable fromcheckpoint_scope_name/some_other_variable
. -
'scope_variable_name': variable
- will initialize giventf.Variable
object with tensor 'scope_variable_name' from the checkpoint. -
'scope_variable_name': list(variable)
- will initialize list of partitioned variables with tensor 'scope_variable_name' from the checkpoint. -
'/': 'scope_name/'
- will load all variables in currentscope_name
from checkpoint's root (e.g. no scope).
Supports loading into partitioned variables, which are represented as '<variable>/part_<part #>'
.
Example:
# Say, '/tmp/model.ckpt' has the following tensors: # -- name='old_scope_1/var1', shape=[20, 2] # -- name='old_scope_1/var2', shape=[50, 4] # -- name='old_scope_2/var3', shape=[100, 100] # Create new model's variables with tf.compat.v1.variable_scope('new_scope_1'): var1 = tf.compat.v1.get_variable('var1', shape=[20, 2], initializer=tf.compat.v1.zeros_initializer()) with tf.compat.v1.variable_scope('new_scope_2'): var2 = tf.compat.v1.get_variable('var2', shape=[50, 4], initializer=tf.compat.v1.zeros_initializer()) # Partition into 5 variables along the first axis. var3 = tf.compat.v1.get_variable(name='var3', shape=[100, 100], initializer=tf.compat.v1.zeros_initializer(), partitioner=lambda shape, dtype: [5, 1]) # Initialize all variables in `new_scope_1` from `old_scope_1`. init_from_checkpoint('/tmp/model.ckpt', {'old_scope_1/': 'new_scope_1'}) # Use names to specify which variables to initialize from checkpoint. init_from_checkpoint('/tmp/model.ckpt', {'old_scope_1/var1': 'new_scope_1/var1', 'old_scope_1/var2': 'new_scope_2/var2'}) # Or use tf.Variable objects to identify what to initialize. init_from_checkpoint('/tmp/model.ckpt', {'old_scope_1/var1': var1, 'old_scope_1/var2': var2}) # Initialize partitioned variables using variable's name init_from_checkpoint('/tmp/model.ckpt', {'old_scope_2/var3': 'new_scope_2/var3'}) # Or specify the list of tf.Variable objects. init_from_checkpoint('/tmp/model.ckpt', {'old_scope_2/var3': var3._get_variable_list()})
Args | |
---|---|
ckpt_dir_or_file | Directory with checkpoints file or path to checkpoint. |
assignment_map | Dict, where keys are names of the variables in the checkpoint and values are current variables or names of current variables (in default graph). |
Raises | |
---|---|
ValueError | If missing variables in current graph, or if missing checkpoints or tensors in checkpoints. |
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Licensed under the Creative Commons Attribution License 3.0.
Code samples licensed under the Apache 2.0 License.
https://www.tensorflow.org/versions/r1.15/api_docs/python/tf/train/init_from_checkpoint