网络参数初始化的优劣在极大程度上决定了网络的最终性能。比较推荐的初始化方式有 He 初始化是，将参数初始化为服从高斯分布或均匀分布的较小随机整数，同时对参数方差加以规范化。

处于稳定状态下的神经网络，其参数和数据均值为 0。

PyTorch 中实现了较多的参数初始化 API, 主要如下：

1. 均匀分布初始化
2. 正态分布初始化
3. 全0初始化
4. 全1初始化
5. 固定值初始化
6. kaiming 初始化
7. xavier 初始化

示例代码：

import torch
import torch.nn.functional as F
import torch.nn as nn


# 1. 均匀分布随机初始化
def test01():

    linear = nn.Linear(5, 3)
    # 从0-1均匀分布产生参数
    nn.init.uniform_(linear.weight)
    print(linear.weight.data)


# 2. 固定初始化
def test02():

    linear = nn.Linear(5, 3)
    nn.init.constant_(linear.weight, 5)
    print(linear.weight.data)


# 3. 全0初始化
def test03():

    linear = nn.Linear(5, 3)
    nn.init.zeros_(linear.weight)
    print(linear.weight.data)


# 4. 全1初始化
def test04():

    linear = nn.Linear(5, 3)
    nn.init.ones_(linear.weight)
    print(linear.weight.data)


# 5. 正态分布随机初始化
def test05():

    linear = nn.Linear(5, 3)
    nn.init.normal_(linear.weight, mean=0, std=1)
    print(linear.weight.data)


# 6. kaiming 初始化
def test06():

    # kaiming 正态分布初始化
    linear = nn.Linear(5, 3)
    nn.init.kaiming_normal_(linear.weight)
    print(linear.weight.data)

    # kaiming 均匀分布初始化
    linear = nn.Linear(5, 3)
    nn.init.kaiming_uniform_(linear.weight)
    print(linear.weight.data)


# 7. xavier 初始化
def test07():

    # xavier 正态分布初始化
    linear = nn.Linear(5, 3)
    nn.init.xavier_normal_(linear.weight)
    print(linear.weight.data)

    # xavier 均匀分布初始化
    linear = nn.Linear(5, 3)
    nn.init.xavier_uniform_(linear.weight)
    print(linear.weight.data)


if __name__ == '__main__':
    test07()