ColossalAI/colossalai/nn/init.py

141 lines
4.2 KiB
Python

import math
import warnings
from torch import Tensor
import torch.nn as nn
def zeros_():
def initializer(tensor: Tensor, fan_in: int = None, fan_out: int = None):
return nn.init.zeros_(tensor)
return initializer
def ones_():
def initializer(tensor: Tensor, fan_in: int = None, fan_out: int = None):
return nn.init.ones_(tensor)
return initializer
def uniform_(a: float = 0., b: float = 1.):
def initializer(tensor: Tensor, fan_in: int = None, fan_out: int = None):
return nn.init.uniform_(tensor, a, b)
return initializer
def normal_(mean: float = 0., std: float = 1.):
def initializer(tensor: Tensor, fan_in: int = None, fan_out: int = None):
return nn.init.normal_(tensor, mean, std)
return initializer
def trunc_normal_(mean: float = 0., std: float = 1., a: float = -2., b: float = 2.):
def initializer(tensor: Tensor, fan_in: int = None, fan_out: int = None):
return nn.init.trunc_normal_(tensor, mean, std, a, b)
return initializer
def kaiming_uniform_(a=0, mode='fan_in', nonlinearity='leaky_relu'):
# adapted from torch.nn.init
def initializer(tensor: Tensor, fan_in: int = None, fan_out: int = None):
if 0 in tensor.shape:
warnings.warn("Initializing zero-element tensors is a no-op")
return tensor
if mode == 'fan_in':
assert fan_in is not None, 'Fan_in is not provided.'
fan = fan_in
elif mode == 'fan_out':
assert fan_out is not None, 'Fan_out is not provided.'
fan = fan_out
else:
raise ValueError(f'Invalid initialization mode \'{mode}\'')
std = nn.init.calculate_gain(nonlinearity, a) / math.sqrt(fan)
bound = math.sqrt(3.) * std
return nn.init.uniform_(tensor, -bound, bound)
return initializer
def kaiming_normal_(a=0, mode='fan_in', nonlinearity='leaky_relu'):
# adapted from torch.nn.init
def initializer(tensor: Tensor, fan_in: int = None, fan_out: int = None):
if 0 in tensor.shape:
warnings.warn("Initializing zero-element tensors is a no-op")
return tensor
if mode == 'fan_in':
assert fan_in is not None, 'Fan_in is not provided.'
fan = fan_in
elif mode == 'fan_out':
assert fan_out is not None, 'Fan_out is not provided.'
fan = fan_out
else:
raise ValueError(f'Invalid initialization mode \'{mode}\'')
std = nn.init.calculate_gain(nonlinearity, a) / math.sqrt(fan)
return nn.init.normal_(tensor, 0, std)
return initializer
def xavier_uniform_(a: float = math.sqrt(3.), scale: float = 2., gain: float = 1.):
# adapted from torch.nn.init
def initializer(tensor: Tensor, fan_in: int = None, fan_out: int = None):
assert fan_in is not None, 'Fan_in is not provided.'
fan = fan_in
if fan_out is not None:
fan += fan_out
std = gain * math.sqrt(scale / float(fan))
bound = a * std
return nn.init.uniform_(tensor, -bound, bound)
return initializer
def xavier_normal_(scale: float = 2., gain: float = 1.):
# adapted from torch.nn.init
def initializer(tensor: Tensor, fan_in: int = None, fan_out: int = None):
assert fan_in is not None, 'Fan_in is not provided.'
fan = fan_in
if fan_out is not None:
fan += fan_out
std = gain * math.sqrt(scale / float(fan))
return nn.init.normal_(tensor, 0., std)
return initializer
def lecun_uniform_():
# adapted from jax.nn.initializers
def initializer(tensor: Tensor, fan_in: int = None, fan_out: int = None):
assert fan_in is not None, 'Fan_in is not provided.'
var = 1.0 / fan_in
bound = math.sqrt(3 * var)
return nn.init.uniform_(tensor, -bound, bound)
return initializer
def lecun_normal_():
# adapted from jax.nn.initializers
def initializer(tensor: Tensor, fan_in: int = None, fan_out: int = None):
assert fan_in is not None, 'Fan_in is not provided.'
std = math.sqrt(1.0 / fan_in)
return nn.init.trunc_normal_(tensor, std=std / .87962566103423978)
return initializer