InternLM/internlm/initialize/initialize_tensor.py

64 lines
1.8 KiB
Python

#!/usr/bin/env python
# -*- encoding: utf-8 -*-
import math
from torch import Tensor, nn
def scaled_init_method_normal(sigma: float = 1.0, num_layers: int = 1):
"""Init method based on N(0, sigma/sqrt(2*num_layers)."""
std = sigma / math.sqrt(2.0 * num_layers)
def init_(tensor):
return nn.init.normal_(tensor, mean=0.0, std=std)
return init_
def normal_(mean: float = 0.0, std: float = 1.0):
r"""Return the initializer filling the input Tensor with values drawn from the normal distribution
.. math::
\mathcal{N}(\text{mean}, \text{std}^2)
Args:
mean (float): the mean of the normal distribution. Defaults 0.0.
std (float): the standard deviation of the normal distribution. Defaults 1.0.
"""
def initializer(tensor: Tensor):
return nn.init.normal_(tensor, mean, std)
return initializer
def scaled_init_method_uniform(sigma: float = 1.0, num_layers: int = 1):
"""Init method based on p(x)=Uniform(-a, a) where std(x)=sigma/sqrt(2*num_layers)."""
std = sigma / math.sqrt(2.0 * num_layers)
a = math.sqrt(3.0 * std)
def init_(tensor):
return nn.init.uniform_(tensor, -a, a)
return init_
def uniform_(mean: float = 0.0, std: float = 1.0):
r"""Return the initializer filling the input Tensor with values drawn from the uniform distribution
.. math::
\mathcal{U}(mean-a, mean+a), where a satisfies \mathcal{U}_{std}=std.
Args:
mean (float): the mean of the uniform distribution. Defaults 0.0.
std (float): the standard deviation of the uniform distribution. Defaults 1.0.
"""
a = math.sqrt(3.0 * std)
def initializer(tensor: Tensor):
return nn.init.uniform_(tensor, mean - a, mean + a)
return initializer