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layers.py
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layers.py
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# AUTOGENERATED! DO NOT EDIT! File to edit: nbs/01_layers.ipynb (unless otherwise specified).
__all__ = ['module', 'Identity', 'Lambda', 'PartialLambda', 'Flatten', 'ToTensorBase', 'View', 'ResizeBatch',
'Debugger', 'sigmoid_range', 'SigmoidRange', 'AdaptiveConcatPool1d', 'AdaptiveConcatPool2d', 'PoolType',
'adaptive_pool', 'PoolFlatten', 'NormType', 'BatchNorm', 'InstanceNorm', 'BatchNorm1dFlat', 'LinBnDrop',
'sigmoid', 'sigmoid_', 'vleaky_relu', 'init_default', 'init_linear', 'ConvLayer', 'AdaptiveAvgPool',
'MaxPool', 'AvgPool', 'trunc_normal_', 'Embedding', 'SelfAttention', 'PooledSelfAttention2d',
'SimpleSelfAttention', 'icnr_init', 'PixelShuffle_ICNR', 'sequential', 'SequentialEx', 'MergeLayer', 'Cat',
'SimpleCNN', 'ProdLayer', 'inplace_relu', 'SEModule', 'ResBlock', 'SEBlock', 'SEResNeXtBlock',
'SeparableBlock', 'TimeDistributed', 'swish', 'Swish', 'MishJitAutoFn', 'mish', 'Mish', 'ParameterModule',
'children_and_parameters', 'has_children', 'flatten_model', 'NoneReduce', 'in_channels']
# Cell
from .imports import *
from .torch_imports import *
from .torch_core import *
from torch.nn.utils import weight_norm, spectral_norm
# Cell
def module(*flds, **defaults):
"Decorator to create an `nn.Module` using `f` as `forward` method"
pa = [inspect.Parameter(o, inspect.Parameter.POSITIONAL_OR_KEYWORD) for o in flds]
pb = [inspect.Parameter(k, inspect.Parameter.POSITIONAL_OR_KEYWORD, default=v)
for k,v in defaults.items()]
params = pa+pb
all_flds = [*flds,*defaults.keys()]
def _f(f):
class c(nn.Module):
def __init__(self, *args, **kwargs):
super().__init__()
for i,o in enumerate(args): kwargs[all_flds[i]] = o
kwargs = merge(defaults,kwargs)
for k,v in kwargs.items(): setattr(self,k,v)
__repr__ = basic_repr(all_flds)
forward = f
c.__signature__ = inspect.Signature(params)
c.__name__ = c.__qualname__ = f.__name__
c.__doc__ = f.__doc__
return c
return _f
# Cell
@module()
def Identity(self, x):
"Do nothing at all"
return x
# Cell
@module('func')
def Lambda(self, x):
"An easy way to create a pytorch layer for a simple `func`"
return self.func(x)
# Cell
class PartialLambda(Lambda):
"Layer that applies `partial(func, **kwargs)`"
def __init__(self, func, **kwargs):
super().__init__(partial(func, **kwargs))
self.repr = f'{func.__name__}, {kwargs}'
def forward(self, x): return self.func(x)
def __repr__(self): return f'{self.__class__.__name__}({self.repr})'
# Cell
@module(full=False)
def Flatten(self, x):
"Flatten `x` to a single dimension, e.g. at end of a model. `full` for rank-1 tensor"
return TensorBase(x.view(-1) if self.full else x.view(x.size(0), -1))
# Cell
@module(tensor_cls=TensorBase)
def ToTensorBase(self, x):
"Remove `tensor_cls` to x"
return self.tensor_cls(x)
# Cell
class View(Module):
"Reshape `x` to `size`"
def __init__(self, *size): self.size = size
def forward(self, x): return x.view(self.size)
# Cell
class ResizeBatch(Module):
"Reshape `x` to `size`, keeping batch dim the same size"
def __init__(self, *size): self.size = size
def forward(self, x): return x.view((x.size(0),) + self.size)
# Cell
@module()
def Debugger(self,x):
"A module to debug inside a model."
set_trace()
return x
# Cell
def sigmoid_range(x, low, high):
"Sigmoid function with range `(low, high)`"
return torch.sigmoid(x) * (high - low) + low
# Cell
@module('low','high')
def SigmoidRange(self, x):
"Sigmoid module with range `(low, high)`"
return sigmoid_range(x, self.low, self.high)
# Cell
class AdaptiveConcatPool1d(Module):
"Layer that concats `AdaptiveAvgPool1d` and `AdaptiveMaxPool1d`"
def __init__(self, size=None):
self.size = size or 1
self.ap = nn.AdaptiveAvgPool1d(self.size)
self.mp = nn.AdaptiveMaxPool1d(self.size)
def forward(self, x): return torch.cat([self.mp(x), self.ap(x)], 1)
# Cell
class AdaptiveConcatPool2d(Module):
"Layer that concats `AdaptiveAvgPool2d` and `AdaptiveMaxPool2d`"
def __init__(self, size=None):
self.size = size or 1
self.ap = nn.AdaptiveAvgPool2d(self.size)
self.mp = nn.AdaptiveMaxPool2d(self.size)
def forward(self, x): return torch.cat([self.mp(x), self.ap(x)], 1)
# Cell
class PoolType: Avg,Max,Cat = 'Avg','Max','Cat'
# Cell
def adaptive_pool(pool_type):
return nn.AdaptiveAvgPool2d if pool_type=='Avg' else nn.AdaptiveMaxPool2d if pool_type=='Max' else AdaptiveConcatPool2d
# Cell
class PoolFlatten(nn.Sequential):
"Combine `nn.AdaptiveAvgPool2d` and `Flatten`."
def __init__(self, pool_type=PoolType.Avg): super().__init__(adaptive_pool(pool_type)(1), Flatten())
# Cell
NormType = Enum('NormType', 'Batch BatchZero Weight Spectral Instance InstanceZero')
# Cell
def _get_norm(prefix, nf, ndim=2, zero=False, **kwargs):
"Norm layer with `nf` features and `ndim` initialized depending on `norm_type`."
assert 1 <= ndim <= 3
bn = getattr(nn, f"{prefix}{ndim}d")(nf, **kwargs)
if bn.affine:
bn.bias.data.fill_(1e-3)
bn.weight.data.fill_(0. if zero else 1.)
return bn
# Cell
@delegates(nn.BatchNorm2d)
def BatchNorm(nf, ndim=2, norm_type=NormType.Batch, **kwargs):
"BatchNorm layer with `nf` features and `ndim` initialized depending on `norm_type`."
return _get_norm('BatchNorm', nf, ndim, zero=norm_type==NormType.BatchZero, **kwargs)
# Cell
@delegates(nn.InstanceNorm2d)
def InstanceNorm(nf, ndim=2, norm_type=NormType.Instance, affine=True, **kwargs):
"InstanceNorm layer with `nf` features and `ndim` initialized depending on `norm_type`."
return _get_norm('InstanceNorm', nf, ndim, zero=norm_type==NormType.InstanceZero, affine=affine, **kwargs)
# Cell
class BatchNorm1dFlat(nn.BatchNorm1d):
"`nn.BatchNorm1d`, but first flattens leading dimensions"
def forward(self, x):
if x.dim()==2: return super().forward(x)
*f,l = x.shape
x = x.contiguous().view(-1,l)
return super().forward(x).view(*f,l)
# Cell
class LinBnDrop(nn.Sequential):
"Module grouping `BatchNorm1d`, `Dropout` and `Linear` layers"
def __init__(self, n_in, n_out, bn=True, p=0., act=None, lin_first=False):
layers = [BatchNorm(n_out if lin_first else n_in, ndim=1)] if bn else []
if p != 0: layers.append(nn.Dropout(p))
lin = [nn.Linear(n_in, n_out, bias=not bn)]
if act is not None: lin.append(act)
layers = lin+layers if lin_first else layers+lin
super().__init__(*layers)
# Cell
def sigmoid(input, eps=1e-7):
"Same as `torch.sigmoid`, plus clamping to `(eps,1-eps)"
return input.sigmoid().clamp(eps,1-eps)
# Cell
def sigmoid_(input, eps=1e-7):
"Same as `torch.sigmoid_`, plus clamping to `(eps,1-eps)"
return input.sigmoid_().clamp_(eps,1-eps)
# Cell
from torch.nn.init import kaiming_uniform_,uniform_,xavier_uniform_,normal_
# Cell
def vleaky_relu(input, inplace=True):
"`F.leaky_relu` with 0.3 slope"
return F.leaky_relu(input, negative_slope=0.3, inplace=inplace)
# Cell
for o in F.relu,nn.ReLU,F.relu6,nn.ReLU6,F.leaky_relu,nn.LeakyReLU:
o.__default_init__ = kaiming_uniform_
# Cell
for o in F.sigmoid,nn.Sigmoid,F.tanh,nn.Tanh,sigmoid,sigmoid_:
o.__default_init__ = xavier_uniform_
# Cell
def init_default(m, func=nn.init.kaiming_normal_):
"Initialize `m` weights with `func` and set `bias` to 0."
if func and hasattr(m, 'weight'): func(m.weight)
with torch.no_grad():
if getattr(m, 'bias', None) is not None: m.bias.fill_(0.)
return m
# Cell
def init_linear(m, act_func=None, init='auto', bias_std=0.01):
if getattr(m,'bias',None) is not None and bias_std is not None:
if bias_std != 0: normal_(m.bias, 0, bias_std)
else: m.bias.data.zero_()
if init=='auto':
if act_func in (F.relu_,F.leaky_relu_): init = kaiming_uniform_
else: init = getattr(act_func.__class__, '__default_init__', None)
if init is None: init = getattr(act_func, '__default_init__', None)
if init is not None: init(m.weight)
# Cell
def _conv_func(ndim=2, transpose=False):
"Return the proper conv `ndim` function, potentially `transposed`."
assert 1 <= ndim <=3
return getattr(nn, f'Conv{"Transpose" if transpose else ""}{ndim}d')
# Cell
defaults.activation=nn.ReLU
# Cell
class ConvLayer(nn.Sequential):
"Create a sequence of convolutional (`ni` to `nf`), ReLU (if `use_activ`) and `norm_type` layers."
@delegates(nn.Conv2d)
def __init__(self, ni, nf, ks=3, stride=1, padding=None, bias=None, ndim=2, norm_type=NormType.Batch, bn_1st=True,
act_cls=defaults.activation, transpose=False, init='auto', xtra=None, bias_std=0.01, **kwargs):
if padding is None: padding = ((ks-1)//2 if not transpose else 0)
bn = norm_type in (NormType.Batch, NormType.BatchZero)
inn = norm_type in (NormType.Instance, NormType.InstanceZero)
if bias is None: bias = not (bn or inn)
conv_func = _conv_func(ndim, transpose=transpose)
conv = conv_func(ni, nf, kernel_size=ks, bias=bias, stride=stride, padding=padding, **kwargs)
act = None if act_cls is None else act_cls()
init_linear(conv, act, init=init, bias_std=bias_std)
if norm_type==NormType.Weight: conv = weight_norm(conv)
elif norm_type==NormType.Spectral: conv = spectral_norm(conv)
layers = [conv]
act_bn = []
if act is not None: act_bn.append(act)
if bn: act_bn.append(BatchNorm(nf, norm_type=norm_type, ndim=ndim))
if inn: act_bn.append(InstanceNorm(nf, norm_type=norm_type, ndim=ndim))
if bn_1st: act_bn.reverse()
layers += act_bn
if xtra: layers.append(xtra)
super().__init__(*layers)
# Cell
def AdaptiveAvgPool(sz=1, ndim=2):
"nn.AdaptiveAvgPool layer for `ndim`"
assert 1 <= ndim <= 3
return getattr(nn, f"AdaptiveAvgPool{ndim}d")(sz)
# Cell
def MaxPool(ks=2, stride=None, padding=0, ndim=2, ceil_mode=False):
"nn.MaxPool layer for `ndim`"
assert 1 <= ndim <= 3
return getattr(nn, f"MaxPool{ndim}d")(ks, stride=stride, padding=padding)
# Cell
def AvgPool(ks=2, stride=None, padding=0, ndim=2, ceil_mode=False):
"nn.AvgPool layer for `ndim`"
assert 1 <= ndim <= 3
return getattr(nn, f"AvgPool{ndim}d")(ks, stride=stride, padding=padding, ceil_mode=ceil_mode)
# Cell
def trunc_normal_(x, mean=0., std=1.):
"Truncated normal initialization (approximation)"
# From https://discuss.pytorch.org/t/implementing-truncated-normal-initializer/4778/12
return x.normal_().fmod_(2).mul_(std).add_(mean)
# Cell
class Embedding(nn.Embedding):
"Embedding layer with truncated normal initialization"
def __init__(self, ni, nf, std=0.01):
super().__init__(ni, nf)
trunc_normal_(self.weight.data, std=std)
# Cell
class SelfAttention(Module):
"Self attention layer for `n_channels`."
def __init__(self, n_channels):
self.query,self.key,self.value = [self._conv(n_channels, c) for c in (n_channels//8,n_channels//8,n_channels)]
self.gamma = nn.Parameter(tensor([0.]))
def _conv(self,n_in,n_out):
return ConvLayer(n_in, n_out, ks=1, ndim=1, norm_type=NormType.Spectral, act_cls=None, bias=False)
def forward(self, x):
#Notation from the paper.
size = x.size()
x = x.view(*size[:2],-1)
f,g,h = self.query(x),self.key(x),self.value(x)
beta = F.softmax(torch.bmm(f.transpose(1,2), g), dim=1)
o = self.gamma * torch.bmm(h, beta) + x
return o.view(*size).contiguous()
# Cell
class PooledSelfAttention2d(Module):
"Pooled self attention layer for 2d."
def __init__(self, n_channels):
self.n_channels = n_channels
self.query,self.key,self.value = [self._conv(n_channels, c) for c in (n_channels//8,n_channels//8,n_channels//2)]
self.out = self._conv(n_channels//2, n_channels)
self.gamma = nn.Parameter(tensor([0.]))
def _conv(self,n_in,n_out):
return ConvLayer(n_in, n_out, ks=1, norm_type=NormType.Spectral, act_cls=None, bias=False)
def forward(self, x):
n_ftrs = x.shape[2]*x.shape[3]
f = self.query(x).view(-1, self.n_channels//8, n_ftrs)
g = F.max_pool2d(self.key(x), [2,2]).view(-1, self.n_channels//8, n_ftrs//4)
h = F.max_pool2d(self.value(x), [2,2]).view(-1, self.n_channels//2, n_ftrs//4)
beta = F.softmax(torch.bmm(f.transpose(1, 2), g), -1)
o = self.out(torch.bmm(h, beta.transpose(1,2)).view(-1, self.n_channels//2, x.shape[2], x.shape[3]))
return self.gamma * o + x
# Cell
def _conv1d_spect(ni:int, no:int, ks:int=1, stride:int=1, padding:int=0, bias:bool=False):
"Create and initialize a `nn.Conv1d` layer with spectral normalization."
conv = nn.Conv1d(ni, no, ks, stride=stride, padding=padding, bias=bias)
nn.init.kaiming_normal_(conv.weight)
if bias: conv.bias.data.zero_()
return spectral_norm(conv)
# Cell
class SimpleSelfAttention(Module):
def __init__(self, n_in:int, ks=1, sym=False):
self.sym,self.n_in = sym,n_in
self.conv = _conv1d_spect(n_in, n_in, ks, padding=ks//2, bias=False)
self.gamma = nn.Parameter(tensor([0.]))
def forward(self,x):
if self.sym:
c = self.conv.weight.view(self.n_in,self.n_in)
c = (c + c.t())/2
self.conv.weight = c.view(self.n_in,self.n_in,1)
size = x.size()
x = x.view(*size[:2],-1)
convx = self.conv(x)
xxT = torch.bmm(x,x.permute(0,2,1).contiguous())
o = torch.bmm(xxT, convx)
o = self.gamma * o + x
return o.view(*size).contiguous()
# Cell
def icnr_init(x, scale=2, init=nn.init.kaiming_normal_):
"ICNR init of `x`, with `scale` and `init` function"
ni,nf,h,w = x.shape
ni2 = int(ni/(scale**2))
k = init(x.new_zeros([ni2,nf,h,w])).transpose(0, 1)
k = k.contiguous().view(ni2, nf, -1)
k = k.repeat(1, 1, scale**2)
return k.contiguous().view([nf,ni,h,w]).transpose(0, 1)
# Cell
class PixelShuffle_ICNR(nn.Sequential):
"Upsample by `scale` from `ni` filters to `nf` (default `ni`), using `nn.PixelShuffle`."
def __init__(self, ni, nf=None, scale=2, blur=False, norm_type=NormType.Weight, act_cls=defaults.activation):
super().__init__()
nf = ifnone(nf, ni)
layers = [ConvLayer(ni, nf*(scale**2), ks=1, norm_type=norm_type, act_cls=act_cls, bias_std=0),
nn.PixelShuffle(scale)]
if norm_type == NormType.Weight:
layers[0][0].weight_v.data.copy_(icnr_init(layers[0][0].weight_v.data))
layers[0][0].weight_g.data.copy_(((layers[0][0].weight_v.data**2).sum(dim=[1,2,3])**0.5)[:,None,None,None])
else:
layers[0][0].weight.data.copy_(icnr_init(layers[0][0].weight.data))
if blur: layers += [nn.ReplicationPad2d((1,0,1,0)), nn.AvgPool2d(2, stride=1)]
super().__init__(*layers)
# Cell
def sequential(*args):
"Create an `nn.Sequential`, wrapping items with `Lambda` if needed"
if len(args) != 1 or not isinstance(args[0], OrderedDict):
args = list(args)
for i,o in enumerate(args):
if not isinstance(o,nn.Module): args[i] = Lambda(o)
return nn.Sequential(*args)
# Cell
class SequentialEx(Module):
"Like `nn.Sequential`, but with ModuleList semantics, and can access module input"
def __init__(self, *layers): self.layers = nn.ModuleList(layers)
def forward(self, x):
res = x
for l in self.layers:
res.orig = x
nres = l(res)
# We have to remove res.orig to avoid hanging refs and therefore memory leaks
res.orig, nres.orig = None, None
res = nres
return res
def __getitem__(self,i): return self.layers[i]
def append(self,l): return self.layers.append(l)
def extend(self,l): return self.layers.extend(l)
def insert(self,i,l): return self.layers.insert(i,l)
# Cell
class MergeLayer(Module):
"Merge a shortcut with the result of the module by adding them or concatenating them if `dense=True`."
def __init__(self, dense:bool=False): self.dense=dense
def forward(self, x): return torch.cat([x,x.orig], dim=1) if self.dense else (x+x.orig)
# Cell
class Cat(nn.ModuleList):
"Concatenate layers outputs over a given dim"
def __init__(self, layers, dim=1):
self.dim=dim
super().__init__(layers)
def forward(self, x): return torch.cat([l(x) for l in self], dim=self.dim)
# Cell
class SimpleCNN(nn.Sequential):
"Create a simple CNN with `filters`."
def __init__(self, filters, kernel_szs=None, strides=None, bn=True):
nl = len(filters)-1
kernel_szs = ifnone(kernel_szs, [3]*nl)
strides = ifnone(strides , [2]*nl)
layers = [ConvLayer(filters[i], filters[i+1], kernel_szs[i], stride=strides[i],
norm_type=(NormType.Batch if bn and i<nl-1 else None)) for i in range(nl)]
layers.append(PoolFlatten())
super().__init__(*layers)
# Cell
class ProdLayer(Module):
"Merge a shortcut with the result of the module by multiplying them."
def forward(self, x): return x * x.orig
# Cell
inplace_relu = partial(nn.ReLU, inplace=True)
# Cell
def SEModule(ch, reduction, act_cls=defaults.activation):
nf = math.ceil(ch//reduction/8)*8
return SequentialEx(nn.AdaptiveAvgPool2d(1),
ConvLayer(ch, nf, ks=1, norm_type=None, act_cls=act_cls),
ConvLayer(nf, ch, ks=1, norm_type=None, act_cls=nn.Sigmoid),
ProdLayer())
# Cell
class ResBlock(Module):
"Resnet block from `ni` to `nh` with `stride`"
@delegates(ConvLayer.__init__)
def __init__(self, expansion, ni, nf, stride=1, groups=1, reduction=None, nh1=None, nh2=None, dw=False, g2=1,
sa=False, sym=False, norm_type=NormType.Batch, act_cls=defaults.activation, ndim=2, ks=3,
pool=AvgPool, pool_first=True, **kwargs):
norm2 = (NormType.BatchZero if norm_type==NormType.Batch else
NormType.InstanceZero if norm_type==NormType.Instance else norm_type)
if nh2 is None: nh2 = nf
if nh1 is None: nh1 = nh2
nf,ni = nf*expansion,ni*expansion
k0 = dict(norm_type=norm_type, act_cls=act_cls, ndim=ndim, **kwargs)
k1 = dict(norm_type=norm2, act_cls=None, ndim=ndim, **kwargs)
convpath = [ConvLayer(ni, nh2, ks, stride=stride, groups=ni if dw else groups, **k0),
ConvLayer(nh2, nf, ks, groups=g2, **k1)
] if expansion == 1 else [
ConvLayer(ni, nh1, 1, **k0),
ConvLayer(nh1, nh2, ks, stride=stride, groups=nh1 if dw else groups, **k0),
ConvLayer(nh2, nf, 1, groups=g2, **k1)]
if reduction: convpath.append(SEModule(nf, reduction=reduction, act_cls=act_cls))
if sa: convpath.append(SimpleSelfAttention(nf,ks=1,sym=sym))
self.convpath = nn.Sequential(*convpath)
idpath = []
if ni!=nf: idpath.append(ConvLayer(ni, nf, 1, act_cls=None, ndim=ndim, **kwargs))
if stride!=1: idpath.insert((1,0)[pool_first], pool(stride, ndim=ndim, ceil_mode=True))
self.idpath = nn.Sequential(*idpath)
self.act = defaults.activation(inplace=True) if act_cls is defaults.activation else act_cls()
def forward(self, x): return self.act(self.convpath(x) + self.idpath(x))
# Cell
def SEBlock(expansion, ni, nf, groups=1, reduction=16, stride=1, **kwargs):
return ResBlock(expansion, ni, nf, stride=stride, groups=groups, reduction=reduction, nh1=nf*2, nh2=nf*expansion, **kwargs)
# Cell
def SEResNeXtBlock(expansion, ni, nf, groups=32, reduction=16, stride=1, base_width=4, **kwargs):
w = math.floor(nf * (base_width / 64)) * groups
return ResBlock(expansion, ni, nf, stride=stride, groups=groups, reduction=reduction, nh2=w, **kwargs)
# Cell
def SeparableBlock(expansion, ni, nf, reduction=16, stride=1, base_width=4, **kwargs):
return ResBlock(expansion, ni, nf, stride=stride, reduction=reduction, nh2=nf*2, dw=True, **kwargs)
# Cell
def _stack_tups(tuples, stack_dim=1):
"Stack tuple of tensors along `stack_dim`"
return tuple(torch.stack([t[i] for t in tuples], dim=stack_dim) for i in range_of(tuples[0]))
# Cell
class TimeDistributed(Module):
"Applies `module` over `tdim` identically for each step, use `low_mem` to compute one at a time."
def __init__(self, module, low_mem=False, tdim=1):
store_attr()
def forward(self, *tensors, **kwargs):
"input x with shape:(bs,seq_len,channels,width,height)"
if self.low_mem or self.tdim!=1:
return self.low_mem_forward(*tensors, **kwargs)
else:
#only support tdim=1
inp_shape = tensors[0].shape
bs, seq_len = inp_shape[0], inp_shape[1]
out = self.module(*[x.view(bs*seq_len, *x.shape[2:]) for x in tensors], **kwargs)
return self.format_output(out, bs, seq_len)
def low_mem_forward(self, *tensors, **kwargs):
"input x with shape:(bs,seq_len,channels,width,height)"
seq_len = tensors[0].shape[self.tdim]
args_split = [torch.unbind(x, dim=self.tdim) for x in tensors]
out = []
for i in range(seq_len):
out.append(self.module(*[args[i] for args in args_split]), **kwargs)
if isinstance(out[0], tuple):
return _stack_tups(out, stack_dim=self.tdim)
return torch.stack(out, dim=self.tdim)
def format_output(self, out, bs, seq_len):
"unstack from batchsize outputs"
if isinstance(out, tuple):
return tuple(out_i.view(bs, seq_len, *out_i.shape[1:]) for out_i in out)
return out.view(bs, seq_len,*out.shape[1:])
def __repr__(self):
return f'TimeDistributed({self.module})'
# Cell
from torch.jit import script
# Cell
@script
def _swish_jit_fwd(x): return x.mul(torch.sigmoid(x))
@script
def _swish_jit_bwd(x, grad_output):
x_sigmoid = torch.sigmoid(x)
return grad_output * (x_sigmoid * (1 + x * (1 - x_sigmoid)))
class _SwishJitAutoFn(torch.autograd.Function):
@staticmethod
def forward(ctx, x):
ctx.save_for_backward(x)
return _swish_jit_fwd(x)
@staticmethod
def backward(ctx, grad_output):
x = ctx.saved_variables[0]
return _swish_jit_bwd(x, grad_output)
# Cell
def swish(x, inplace=False): return _SwishJitAutoFn.apply(x)
# Cell
class Swish(Module):
def forward(self, x): return _SwishJitAutoFn.apply(x)
# Cell
@script
def _mish_jit_fwd(x): return x.mul(torch.tanh(F.softplus(x)))
@script
def _mish_jit_bwd(x, grad_output):
x_sigmoid = torch.sigmoid(x)
x_tanh_sp = F.softplus(x).tanh()
return grad_output.mul(x_tanh_sp + x * x_sigmoid * (1 - x_tanh_sp * x_tanh_sp))
class MishJitAutoFn(torch.autograd.Function):
@staticmethod
def forward(ctx, x):
ctx.save_for_backward(x)
return _mish_jit_fwd(x)
@staticmethod
def backward(ctx, grad_output):
x = ctx.saved_variables[0]
return _mish_jit_bwd(x, grad_output)
# Cell
def mish(x): return F.mish(x) if torch.__version__ >= '1.9' else MishJitAutoFn.apply(x)
# Cell
class Mish(Module):
def forward(self, x): return MishJitAutoFn.apply(x)
# Cell
if ismin_torch('1.9'): Mish = nn.Mish
# Cell
for o in swish,Swish,mish,Mish: o.__default_init__ = kaiming_uniform_
# Cell
class ParameterModule(Module):
"Register a lone parameter `p` in a module."
def __init__(self, p): self.val = p
def forward(self, x): return x
# Cell
def children_and_parameters(m):
"Return the children of `m` and its direct parameters not registered in modules."
children = list(m.children())
children_p = sum([[id(p) for p in c.parameters()] for c in m.children()],[])
for p in m.parameters():
if id(p) not in children_p: children.append(ParameterModule(p))
return children
# Cell
def has_children(m):
try: next(m.children())
except StopIteration: return False
return True
# Cell
def flatten_model(m):
"Return the list of all submodules and parameters of `m`"
return sum(map(flatten_model,children_and_parameters(m)),[]) if has_children(m) else [m]
# Cell
class NoneReduce():
"A context manager to evaluate `loss_func` with none reduce."
def __init__(self, loss_func): self.loss_func,self.old_red = loss_func,None
def __enter__(self):
if hasattr(self.loss_func, 'reduction'):
self.old_red = self.loss_func.reduction
self.loss_func.reduction = 'none'
return self.loss_func
else: return partial(self.loss_func, reduction='none')
def __exit__(self, type, value, traceback):
if self.old_red is not None: self.loss_func.reduction = self.old_red
# Cell
def in_channels(m):
"Return the shape of the first weight layer in `m`."
for l in flatten_model(m):
if getattr(l, 'weight', None) is not None and l.weight.ndim==4:
return l.weight.shape[1]
raise Exception('No weight layer')