Add GaussianDropout layer.

This commit is contained in:
Francois Chollet 2023-04-27 20:27:23 -07:00
parent e1aa2c513a
commit 66e586ec70
5 changed files with 94 additions and 1 deletions

@ -8,3 +8,4 @@ from keras_core.layers.regularization.activity_regularization import (
ActivityRegularization,
)
from keras_core.layers.regularization.dropout import Dropout
from keras_core.layers.regularization.gaussian_dropout import GaussianDropout

@ -1,4 +1,3 @@
from keras_core import backend
from keras_core import constraints
from keras_core import initializers
from keras_core import operations as ops

@ -338,6 +338,7 @@ class Layer(Operation):
kwargs["training"] = training
# TODO: Populate mask argument(s)
# if self._mask_has_training_arg():
# Call the layer.
try:

@ -0,0 +1,63 @@
import math
from keras_core import backend
from keras_core import layers
from keras_core import operations as ops
from keras_core.api_export import keras_core_export
@keras_core_export("keras_core.layers.GaussianDropout")
class GaussianDropout(layers.Layer):
"""Apply multiplicative 1-centered Gaussian noise.
As it is a regularization layer, it is only active at training time.
Args:
rate: Float, drop probability (as with `Dropout`).
The multiplicative noise will have
standard deviation `sqrt(rate / (1 - rate))`.
seed: Integer, optional random seed to enable deterministic behavior.
Call arguments:
inputs: Input tensor (of any rank).
training: Python boolean indicating whether the layer should behave in
training mode (adding dropout) or in inference mode (doing nothing).
"""
def __init__(
self, rate, noise_shape=None, seed=None, name=None, dtype=None
):
super().__init__(name=name, dtype=dtype)
if isinstance(rate, (int, float)) and not 0 <= rate <= 1:
raise ValueError(
f"Invalid value received for argument "
"`rate`. Expected a float value between 0 and 1. "
f"Received: rate={rate}"
)
self.rate = rate
self.seed = seed
self.noise_shape = noise_shape
self.seed_generator = backend.random.SeedGenerator(seed)
self.supports_masking = True
def call(self, inputs, training=False):
if training and self.rate > 0:
stddev = math.sqrt(self.rate / (1.0 - self.rate))
return inputs * backend.random.normal(
shape=ops.shape(inputs),
mean=1.0,
stddev=stddev,
seed=self.seed_generator,
)
return inputs
def compute_output_shape(self, input_shape):
return input_shape
def get_config(self):
base_config = super().get_config()
config = {
"rate": self.rate,
"seed": self.seed,
}
return {**base_config, **config}

@ -0,0 +1,29 @@
import numpy as np
from keras_core import layers
from keras_core import testing
class GaussianDropoutTest(testing.TestCase):
def test_gaussian_dropout_basics(self):
self.run_layer_test(
layers.Dropout,
init_kwargs={
"rate": 0.2,
},
input_shape=(2, 3),
expected_output_shape=(2, 3),
expected_num_trainable_weights=0,
expected_num_non_trainable_weights=0,
expected_num_seed_generators=1,
expected_num_losses=0,
supports_masking=True,
)
def test_gaussian_dropout_correctness(self):
inputs = np.ones((20, 500))
layer = layers.GaussianDropout(0.3, seed=1337)
outputs = layer(inputs, training=True)
self.assertAllClose(
np.std(outputs), np.sqrt(0.3 / (1 - 0.3)), atol=0.02
)