naswot/models/cell_searchs/search_model_random.py
2020-06-03 12:59:01 +01:00

82 lines
3.2 KiB
Python

##################################################
# Copyright (c) Xuanyi Dong [GitHub D-X-Y], 2019 #
##############################################################################
# Random Search and Reproducibility for Neural Architecture Search, UAI 2019 #
##############################################################################
import torch, random
import torch.nn as nn
from copy import deepcopy
from ..cell_operations import ResNetBasicblock
from .search_cells import NAS201SearchCell as SearchCell
from .genotypes import Structure
class TinyNetworkRANDOM(nn.Module):
def __init__(self, C, N, max_nodes, num_classes, search_space, affine, track_running_stats):
super(TinyNetworkRANDOM, self).__init__()
self._C = C
self._layerN = N
self.max_nodes = max_nodes
self.stem = nn.Sequential(
nn.Conv2d(3, C, kernel_size=3, padding=1, bias=False),
nn.BatchNorm2d(C))
layer_channels = [C ] * N + [C*2 ] + [C*2 ] * N + [C*4 ] + [C*4 ] * N
layer_reductions = [False] * N + [True] + [False] * N + [True] + [False] * N
C_prev, num_edge, edge2index = C, None, None
self.cells = nn.ModuleList()
for index, (C_curr, reduction) in enumerate(zip(layer_channels, layer_reductions)):
if reduction:
cell = ResNetBasicblock(C_prev, C_curr, 2)
else:
cell = SearchCell(C_prev, C_curr, 1, max_nodes, search_space, affine, track_running_stats)
if num_edge is None: num_edge, edge2index = cell.num_edges, cell.edge2index
else: assert num_edge == cell.num_edges and edge2index == cell.edge2index, 'invalid {:} vs. {:}.'.format(num_edge, cell.num_edges)
self.cells.append( cell )
C_prev = cell.out_dim
self.op_names = deepcopy( search_space )
self._Layer = len(self.cells)
self.edge2index = edge2index
self.lastact = nn.Sequential(nn.BatchNorm2d(C_prev), nn.ReLU(inplace=True))
self.global_pooling = nn.AdaptiveAvgPool2d(1)
self.classifier = nn.Linear(C_prev, num_classes)
self.arch_cache = None
def get_message(self):
string = self.extra_repr()
for i, cell in enumerate(self.cells):
string += '\n {:02d}/{:02d} :: {:}'.format(i, len(self.cells), cell.extra_repr())
return string
def extra_repr(self):
return ('{name}(C={_C}, Max-Nodes={max_nodes}, N={_layerN}, L={_Layer})'.format(name=self.__class__.__name__, **self.__dict__))
def random_genotype(self, set_cache):
genotypes = []
for i in range(1, self.max_nodes):
xlist = []
for j in range(i):
node_str = '{:}<-{:}'.format(i, j)
op_name = random.choice( self.op_names )
xlist.append((op_name, j))
genotypes.append( tuple(xlist) )
arch = Structure( genotypes )
if set_cache: self.arch_cache = arch
return arch
def forward(self, inputs):
feature = self.stem(inputs)
for i, cell in enumerate(self.cells):
if isinstance(cell, SearchCell):
feature = cell.forward_dynamic(feature, self.arch_cache)
else: feature = cell(feature)
out = self.lastact(feature)
out = self.global_pooling( out )
out = out.view(out.size(0), -1)
logits = self.classifier(out)
return out, logits