1# Copyright 2017 The TensorFlow Authors. All Rights Reserved. 2# 3# Licensed under the Apache License, Version 2.0 (the "License"); 4# you may not use this file except in compliance with the License. 5# You may obtain a copy of the License at 6# 7# http://www.apache.org/licenses/LICENSE-2.0 8# 9# Unless required by applicable law or agreed to in writing, software 10# distributed under the License is distributed on an "AS IS" BASIS, 11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12# See the License for the specific language governing permissions and 13# limitations under the License. 14# ============================================================================== 15"""Resampling dataset transformations.""" 16from __future__ import absolute_import 17from __future__ import division 18from __future__ import print_function 19 20from tensorflow.python.util import deprecation 21from tensorflow.python.util.tf_export import tf_export 22 23 24@deprecation.deprecated(None, "Use `tf.data.Dataset.rejection_resample(...)`.") 25@tf_export("data.experimental.rejection_resample") 26def rejection_resample(class_func, target_dist, initial_dist=None, seed=None): 27 """A transformation that resamples a dataset to achieve a target distribution. 28 29 **NOTE** Resampling is performed via rejection sampling; some fraction 30 of the input values will be dropped. 31 32 Args: 33 class_func: A function mapping an element of the input dataset to a scalar 34 `tf.int32` tensor. Values should be in `[0, num_classes)`. 35 target_dist: A floating point type tensor, shaped `[num_classes]`. 36 initial_dist: (Optional.) A floating point type tensor, shaped 37 `[num_classes]`. If not provided, the true class distribution is 38 estimated live in a streaming fashion. 39 seed: (Optional.) Python integer seed for the resampler. 40 41 Returns: 42 A `Dataset` transformation function, which can be passed to 43 `tf.data.Dataset.apply`. 44 """ 45 def _apply_fn(dataset): 46 """Function from `Dataset` to `Dataset` that applies the transformation.""" 47 48 return dataset.rejection_resample( 49 class_func=class_func, 50 target_dist=target_dist, 51 initial_dist=initial_dist, 52 seed=seed) 53 54 return _apply_fn 55