46 lines
1.8 KiB
Python
46 lines
1.8 KiB
Python
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# Copyright 2017 The TensorFlow Authors. All Rights Reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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# ==============================================================================
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"""Scan dataset transformation."""
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from tensorflow.python.util import deprecation
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from tensorflow.python.util.tf_export import tf_export
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@deprecation.deprecated(None, "Use `tf.data.Dataset.scan(...) instead")
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@tf_export("data.experimental.scan")
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def scan(initial_state, scan_func):
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"""A transformation that scans a function across an input dataset.
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This transformation is a stateful relative of `tf.data.Dataset.map`.
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In addition to mapping `scan_func` across the elements of the input dataset,
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`scan()` accumulates one or more state tensors, whose initial values are
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`initial_state`.
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Args:
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initial_state: A nested structure of tensors, representing the initial state
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of the accumulator.
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scan_func: A function that maps `(old_state, input_element)` to
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`(new_state, output_element)`. It must take two arguments and return a
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pair of nested structures of tensors. The `new_state` must match the
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structure of `initial_state`.
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Returns:
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A `Dataset` transformation function, which can be passed to
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`tf.data.Dataset.apply`.
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"""
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def _apply_fn(dataset):
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return dataset.scan(initial_state=initial_state, scan_func=scan_func)
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return _apply_fn
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