autodl-projects/lib/nas_infer_model/DXYs/ImageNet.py
2019-09-28 18:24:47 +10:00

78 lines
2.7 KiB
Python

import torch
import torch.nn as nn
from .construct_utils import drop_path
from .base_cells import InferCell
from .head_utils import ImageNetHEAD, AuxiliaryHeadImageNet
class NetworkImageNet(nn.Module):
def __init__(self, C, N, auxiliary, genotype, num_classes):
super(NetworkImageNet, self).__init__()
self._C = C
self._layerN = N
layer_channels = [C ] * N + [C*2 ] + [C*2 ] * N + [C*4 ] + [C*4] * N
layer_reductions = [False] * N + [True] + [False] * N + [True] + [False] * N
self.stem0 = nn.Sequential(
nn.Conv2d(3, C // 2, kernel_size=3, stride=2, padding=1, bias=False),
nn.BatchNorm2d(C // 2),
nn.ReLU(inplace=True),
nn.Conv2d(C // 2, C, 3, stride=2, padding=1, bias=False),
nn.BatchNorm2d(C),
)
self.stem1 = nn.Sequential(
nn.ReLU(inplace=True),
nn.Conv2d(C, C, 3, stride=2, padding=1, bias=False),
nn.BatchNorm2d(C),
)
C_prev_prev, C_prev, C_curr, reduction_prev = C, C, C, True
self.cells = nn.ModuleList()
self.auxiliary_index = None
for i, (C_curr, reduction) in enumerate(zip(layer_channels, layer_reductions)):
cell = InferCell(genotype, C_prev_prev, C_prev, C_curr, reduction, reduction_prev)
reduction_prev = reduction
self.cells += [cell]
C_prev_prev, C_prev = C_prev, cell._multiplier * C_curr
if reduction and C_curr == C*4:
C_to_auxiliary = C_prev
self.auxiliary_index = i
self._NNN = len(self.cells)
if auxiliary:
self.auxiliary_head = AuxiliaryHeadImageNet(C_to_auxiliary, num_classes)
else:
self.auxiliary_head = None
self.global_pooling = nn.AvgPool2d(7)
self.classifier = nn.Linear(C_prev, num_classes)
self.drop_path_prob = -1
def update_drop_path(self, drop_path_prob):
self.drop_path_prob = drop_path_prob
def extra_repr(self):
return ('{name}(C={_C}, N=[{_layerN}, {_NNN}], aux-index={auxiliary_index}, drop-path={drop_path_prob})'.format(name=self.__class__.__name__, **self.__dict__))
def get_message(self):
return self.extra_repr()
def auxiliary_param(self):
if self.auxiliary_head is None: return []
else: return list( self.auxiliary_head.parameters() )
def forward(self, inputs):
s0 = self.stem0(inputs)
s1 = self.stem1(s0)
logits_aux = None
for i, cell in enumerate(self.cells):
s0, s1 = s1, cell(s0, s1, self.drop_path_prob)
if i == self.auxiliary_index and self.auxiliary_head and self.training:
logits_aux = self.auxiliary_head(s1)
out = self.global_pooling(s1)
logits = self.classifier(out.view(out.size(0), -1))
if logits_aux is None: return out, logits
else : return out, [logits, logits_aux]