149 lines
4.9 KiB
Python
149 lines
4.9 KiB
Python
|
# Copyright 2015 The TensorFlow Authors. All Rights Reserved.
|
||
|
#
|
||
|
# Licensed under the Apache License, Version 2.0 (the "License");
|
||
|
# you may not use this file except in compliance with the License.
|
||
|
# You may obtain a copy of the License at
|
||
|
#
|
||
|
# http://www.apache.org/licenses/LICENSE-2.0
|
||
|
#
|
||
|
# Unless required by applicable law or agreed to in writing, software
|
||
|
# distributed under the License is distributed on an "AS IS" BASIS,
|
||
|
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||
|
# See the License for the specific language governing permissions and
|
||
|
# limitations under the License.
|
||
|
# ==============================================================================
|
||
|
"""Average pooling 1D layer."""
|
||
|
|
||
|
|
||
|
import functools
|
||
|
|
||
|
from keras import backend
|
||
|
from keras.layers.pooling.base_pooling1d import Pooling1D
|
||
|
|
||
|
# isort: off
|
||
|
from tensorflow.python.util.tf_export import keras_export
|
||
|
|
||
|
|
||
|
@keras_export("keras.layers.AveragePooling1D", "keras.layers.AvgPool1D")
|
||
|
class AveragePooling1D(Pooling1D):
|
||
|
"""Average pooling for temporal data.
|
||
|
|
||
|
Downsamples the input representation by taking the average value over the
|
||
|
window defined by `pool_size`. The window is shifted by `strides`. The
|
||
|
resulting output when using "valid" padding option has a shape of:
|
||
|
`output_shape = (input_shape - pool_size + 1) / strides)`
|
||
|
|
||
|
The resulting output shape when using the "same" padding option is:
|
||
|
`output_shape = input_shape / strides`
|
||
|
|
||
|
For example, for strides=1 and padding="valid":
|
||
|
|
||
|
>>> x = tf.constant([1., 2., 3., 4., 5.])
|
||
|
>>> x = tf.reshape(x, [1, 5, 1])
|
||
|
>>> x
|
||
|
<tf.Tensor: shape=(1, 5, 1), dtype=float32, numpy=
|
||
|
array([[[1.],
|
||
|
[2.],
|
||
|
[3.],
|
||
|
[4.],
|
||
|
[5.]], dtype=float32)>
|
||
|
>>> avg_pool_1d = tf.keras.layers.AveragePooling1D(pool_size=2,
|
||
|
... strides=1, padding='valid')
|
||
|
>>> avg_pool_1d(x)
|
||
|
<tf.Tensor: shape=(1, 4, 1), dtype=float32, numpy=
|
||
|
array([[[1.5],
|
||
|
[2.5],
|
||
|
[3.5],
|
||
|
[4.5]]], dtype=float32)>
|
||
|
|
||
|
For example, for strides=2 and padding="valid":
|
||
|
|
||
|
>>> x = tf.constant([1., 2., 3., 4., 5.])
|
||
|
>>> x = tf.reshape(x, [1, 5, 1])
|
||
|
>>> x
|
||
|
<tf.Tensor: shape=(1, 5, 1), dtype=float32, numpy=
|
||
|
array([[[1.],
|
||
|
[2.],
|
||
|
[3.],
|
||
|
[4.],
|
||
|
[5.]], dtype=float32)>
|
||
|
>>> avg_pool_1d = tf.keras.layers.AveragePooling1D(pool_size=2,
|
||
|
... strides=2, padding='valid')
|
||
|
>>> avg_pool_1d(x)
|
||
|
<tf.Tensor: shape=(1, 2, 1), dtype=float32, numpy=
|
||
|
array([[[1.5],
|
||
|
[3.5]]], dtype=float32)>
|
||
|
|
||
|
For example, for strides=1 and padding="same":
|
||
|
|
||
|
>>> x = tf.constant([1., 2., 3., 4., 5.])
|
||
|
>>> x = tf.reshape(x, [1, 5, 1])
|
||
|
>>> x
|
||
|
<tf.Tensor: shape=(1, 5, 1), dtype=float32, numpy=
|
||
|
array([[[1.],
|
||
|
[2.],
|
||
|
[3.],
|
||
|
[4.],
|
||
|
[5.]], dtype=float32)>
|
||
|
>>> avg_pool_1d = tf.keras.layers.AveragePooling1D(pool_size=2,
|
||
|
... strides=1, padding='same')
|
||
|
>>> avg_pool_1d(x)
|
||
|
<tf.Tensor: shape=(1, 5, 1), dtype=float32, numpy=
|
||
|
array([[[1.5],
|
||
|
[2.5],
|
||
|
[3.5],
|
||
|
[4.5],
|
||
|
[5.]]], dtype=float32)>
|
||
|
|
||
|
Args:
|
||
|
pool_size: Integer, size of the average pooling windows.
|
||
|
strides: Integer, or None. Factor by which to downscale.
|
||
|
E.g. 2 will halve the input.
|
||
|
If None, it will default to `pool_size`.
|
||
|
padding: One of `"valid"` or `"same"` (case-insensitive).
|
||
|
`"valid"` means no padding. `"same"` results in padding evenly to
|
||
|
the left/right or up/down of the input such that output has the same
|
||
|
height/width dimension as the input.
|
||
|
data_format: A string,
|
||
|
one of `channels_last` (default) or `channels_first`.
|
||
|
The ordering of the dimensions in the inputs.
|
||
|
`channels_last` corresponds to inputs with shape
|
||
|
`(batch, steps, features)` while `channels_first`
|
||
|
corresponds to inputs with shape
|
||
|
`(batch, features, steps)`.
|
||
|
|
||
|
Input shape:
|
||
|
- If `data_format='channels_last'`:
|
||
|
3D tensor with shape `(batch_size, steps, features)`.
|
||
|
- If `data_format='channels_first'`:
|
||
|
3D tensor with shape `(batch_size, features, steps)`.
|
||
|
|
||
|
Output shape:
|
||
|
- If `data_format='channels_last'`:
|
||
|
3D tensor with shape `(batch_size, downsampled_steps, features)`.
|
||
|
- If `data_format='channels_first'`:
|
||
|
3D tensor with shape `(batch_size, features, downsampled_steps)`.
|
||
|
"""
|
||
|
|
||
|
def __init__(
|
||
|
self,
|
||
|
pool_size=2,
|
||
|
strides=None,
|
||
|
padding="valid",
|
||
|
data_format="channels_last",
|
||
|
**kwargs
|
||
|
):
|
||
|
super().__init__(
|
||
|
functools.partial(backend.pool2d, pool_mode="avg"),
|
||
|
pool_size=pool_size,
|
||
|
strides=strides,
|
||
|
padding=padding,
|
||
|
data_format=data_format,
|
||
|
**kwargs
|
||
|
)
|
||
|
|
||
|
|
||
|
# Alias
|
||
|
|
||
|
AvgPool1D = AveragePooling1D
|