w = torch.empty(2, 3) # 1. 均匀分布 - u(a,b) # torch.nn.init.uniform_(tensor, a=0, b=1) nn.init.uniform_(w) # tensor([[ 0.0578, 0.3402, 0.5034], # [ 0.7865, 0.7280, 0.6269]]) # 2. 正态分布 - N(mean, std) # torch.nn.init.normal_(tensor, mean=0, std=1) nn.init.normal_(w) # tensor([[ 0.3326, 0.0171, -0.6745], # [ 0.1669, 0.1747, 0.0472]]) # 3. 常数 - 固定值 val # torch.nn.init.constant_(tensor, val) nn.init.constant_(w, 0.3) # tensor([[ 0.3000, 0.3000, 0.3000], # [ 0.3000, 0.3000, 0.3000]]) # 4. 对角线为 1,其它为 0 # torch.nn.init.eye_(tensor) nn.init.eye_(w) # tensor([[ 1., 0., 0.], # [ 0., 1., 0.]]) # 5. Dirac delta 函数初始化,仅适用于 {3, 4, 5}-维的 torch.Tensor # torch.nn.init.dirac_(tensor) w1 = torch.empty(3, 16, 5, 5) nn.init.dirac_(w1) # 6. xavier_uniform 初始化 # torch.nn.init.xavier_uniform_(tensor, gain=1) # From - Understanding the difficulty of training deep feedforward neural networks - Bengio 2010 nn.init.xavier_uniform_(w, gain=nn.init.calculate_gain('relu')) # tensor([[ 1.3374, 0.7932, -0.0891], # [-1.3363, -0.0206, -0.9346]]) # 7. xavier_normal 初始化 # torch.nn.init.xavier_normal_(tensor, gain=1) nn.init.xavier_normal_(w) # tensor([[-0.1777, 0.6740, 0.1139], # [ 0.3018, -0.2443, 0.6824]]) # 8. kaiming_uniform 初始化 # From - Delving deep into rectifiers: Surpassing human-level performance on ImageNet classification - HeKaiming 2015 # torch.nn.init.kaiming_uniform_(tensor, a=0, mode='fan_in', nonlinearity='leaky_relu') nn.init.kaiming_uniform_(w, mode='fan_in', nonlinearity='relu') # tensor([[ 0.6426, -0.9582, -1.1783], # [-0.0515, -0.4975, 1.3237]]) # 9. kaiming_normal 初始化 # torch.nn.init.kaiming_normal_(tensor, a=0, mode='fan_in', nonlinearity='leaky_relu') nn.init.kaiming_normal_(w, mode='fan_out', nonlinearity='relu') # tensor([[ 0.2530, -0.4382, 1.5995], # [ 0.0544, 1.6392, -2.0752]]) # 10. 正交矩阵 - (semi)orthogonal matrix # From - Exact solutions to the nonlinear dynamics of learning in deep linear neural networks - Saxe 2013 # torch.nn.init.orthogonal_(tensor, gain=1) nn.init.orthogonal_(w) # tensor([[ 0.5786, -0.5642, -0.5890], # [-0.7517, -0.0886, -0.6536]]) # 11. 稀疏矩阵 - sparse matrix # 非零元素采用正态分布 N(0, 0.01) 初始化. # From - Deep learning via Hessian-free optimization - Martens 2010 # torch.nn.init.sparse_(tensor, sparsity, std=0.01) nn.init.sparse_(w, sparsity=0.1) # tensor(1.00000e-03 * # [[-0.3382, 1.9501, -1.7761], # [ 0.0000, 0.0000, 0.0000]])