Files
wehub-resource-sync 26446540fa
Lint / lint (push) Waiting to run
CI / MacOS (push) Waiting to run
CI / Windows (push) Waiting to run
chore: import upstream snapshot with attribution
2026-07-13 13:36:25 +08:00

76 lines
2.5 KiB
Python

# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements. See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership. The ASF licenses this file
# to you 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.
# pylint: disable=invalid-name, line-too-long, unused-variable, too-many-locals
# ruff: noqa: E741
"""LRN in python"""
from itertools import product
import numpy as np
def lrn_python(a_np, size, axis, bias, alpha, beta):
"""Local response normalization operator in NCHW layout.
Parameters
----------
a_np : numpy.ndarray
4-D with shape [batch, in_channel, in_height, in_width]
size : int
normalization window size
axis : int
input data layout channel axis
bias : float
offset to avoid dividing by 0. constant value
alpha : float
constant value
beta : float
exponent constant value
Returns
-------
lrn_out : np.ndarray
4-D with shape [batch, out_channel, out_height, out_width]
"""
radius = size // 2
sqr_sum = np.zeros(shape=a_np.shape).astype(a_np.dtype)
for i, j, k, l in product(*[range(_axis) for _axis in a_np.shape]):
axis_size = a_np.shape[axis]
if axis == 1:
# NCHW layout
sum_start = j - radius if j - radius >= 0 else 0
sum_end = j + radius + 1 if j + radius + 1 < axis_size else axis_size
sqr_sum[i, j, k, l] = sum(
a_np[i, sum_start:sum_end, k, l] * a_np[i, sum_start:sum_end, k, l]
)
elif axis == 3:
# NHWC layout
sum_start = l - radius if l - radius >= 0 else 0
sum_end = l + radius + 1 if l + radius + 1 < axis_size else axis_size
sqr_sum[i, j, k, l] = sum(
a_np[i, j, k, sum_start:sum_end] * a_np[i, j, k, sum_start:sum_end]
)
sqr_sum_up = np.power((bias + (alpha * sqr_sum / size)), beta)
lrn_out = np.divide(a_np, sqr_sum_up)
return lrn_out