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

198 lines
7.4 KiB
Python

##################################################
# Copyright (c) Xuanyi Dong [GitHub D-X-Y], 2019 #
##################################################
import math, random, torch
import warnings
import torch.nn as nn
import torch.nn.functional as F
from copy import deepcopy
from ..cell_operations import OPS
# This module is used for NAS-Bench-201, represents a small search space with a complete DAG
class NAS201SearchCell(nn.Module):
def __init__(self, C_in, C_out, stride, max_nodes, op_names, affine=False, track_running_stats=True):
super(NAS201SearchCell, self).__init__()
self.op_names = deepcopy(op_names)
self.edges = nn.ModuleDict()
self.max_nodes = max_nodes
self.in_dim = C_in
self.out_dim = C_out
for i in range(1, max_nodes):
for j in range(i):
node_str = '{:}<-{:}'.format(i, j)
if j == 0:
xlists = [OPS[op_name](C_in , C_out, stride, affine, track_running_stats) for op_name in op_names]
else:
xlists = [OPS[op_name](C_in , C_out, 1, affine, track_running_stats) for op_name in op_names]
self.edges[ node_str ] = nn.ModuleList( xlists )
self.edge_keys = sorted(list(self.edges.keys()))
self.edge2index = {key:i for i, key in enumerate(self.edge_keys)}
self.num_edges = len(self.edges)
def extra_repr(self):
string = 'info :: {max_nodes} nodes, inC={in_dim}, outC={out_dim}'.format(**self.__dict__)
return string
def forward(self, inputs, weightss):
nodes = [inputs]
for i in range(1, self.max_nodes):
inter_nodes = []
for j in range(i):
node_str = '{:}<-{:}'.format(i, j)
weights = weightss[ self.edge2index[node_str] ]
inter_nodes.append( sum( layer(nodes[j]) * w for layer, w in zip(self.edges[node_str], weights) ) )
nodes.append( sum(inter_nodes) )
return nodes[-1]
# GDAS
def forward_gdas(self, inputs, hardwts, index):
nodes = [inputs]
for i in range(1, self.max_nodes):
inter_nodes = []
for j in range(i):
node_str = '{:}<-{:}'.format(i, j)
weights = hardwts[ self.edge2index[node_str] ]
argmaxs = index[ self.edge2index[node_str] ].item()
weigsum = sum( weights[_ie] * edge(nodes[j]) if _ie == argmaxs else weights[_ie] for _ie, edge in enumerate(self.edges[node_str]) )
inter_nodes.append( weigsum )
nodes.append( sum(inter_nodes) )
return nodes[-1]
# joint
def forward_joint(self, inputs, weightss):
nodes = [inputs]
for i in range(1, self.max_nodes):
inter_nodes = []
for j in range(i):
node_str = '{:}<-{:}'.format(i, j)
weights = weightss[ self.edge2index[node_str] ]
#aggregation = sum( layer(nodes[j]) * w for layer, w in zip(self.edges[node_str], weights) ) / weights.numel()
aggregation = sum( layer(nodes[j]) * w for layer, w in zip(self.edges[node_str], weights) )
inter_nodes.append( aggregation )
nodes.append( sum(inter_nodes) )
return nodes[-1]
# uniform random sampling per iteration, SETN
def forward_urs(self, inputs):
nodes = [inputs]
for i in range(1, self.max_nodes):
while True: # to avoid select zero for all ops
sops, has_non_zero = [], False
for j in range(i):
node_str = '{:}<-{:}'.format(i, j)
candidates = self.edges[node_str]
select_op = random.choice(candidates)
sops.append( select_op )
if not hasattr(select_op, 'is_zero') or select_op.is_zero is False: has_non_zero=True
if has_non_zero: break
inter_nodes = []
for j, select_op in enumerate(sops):
inter_nodes.append( select_op(nodes[j]) )
nodes.append( sum(inter_nodes) )
return nodes[-1]
# select the argmax
def forward_select(self, inputs, weightss):
nodes = [inputs]
for i in range(1, self.max_nodes):
inter_nodes = []
for j in range(i):
node_str = '{:}<-{:}'.format(i, j)
weights = weightss[ self.edge2index[node_str] ]
inter_nodes.append( self.edges[node_str][ weights.argmax().item() ]( nodes[j] ) )
#inter_nodes.append( sum( layer(nodes[j]) * w for layer, w in zip(self.edges[node_str], weights) ) )
nodes.append( sum(inter_nodes) )
return nodes[-1]
# forward with a specific structure
def forward_dynamic(self, inputs, structure):
nodes = [inputs]
for i in range(1, self.max_nodes):
cur_op_node = structure.nodes[i-1]
inter_nodes = []
for op_name, j in cur_op_node:
node_str = '{:}<-{:}'.format(i, j)
op_index = self.op_names.index( op_name )
inter_nodes.append( self.edges[node_str][op_index]( nodes[j] ) )
nodes.append( sum(inter_nodes) )
return nodes[-1]
class MixedOp(nn.Module):
def __init__(self, space, C, stride, affine, track_running_stats):
super(MixedOp, self).__init__()
self._ops = nn.ModuleList()
for primitive in space:
op = OPS[primitive](C, C, stride, affine, track_running_stats)
self._ops.append(op)
def forward_gdas(self, x, weights, index):
return self._ops[index](x) * weights[index]
def forward_darts(self, x, weights):
return sum(w * op(x) for w, op in zip(weights, self._ops))
# Learning Transferable Architectures for Scalable Image Recognition, CVPR 2018
class NASNetSearchCell(nn.Module):
def __init__(self, space, steps, multiplier, C_prev_prev, C_prev, C, reduction, reduction_prev, affine, track_running_stats):
super(NASNetSearchCell, self).__init__()
self.reduction = reduction
self.op_names = deepcopy(space)
if reduction_prev: self.preprocess0 = OPS['skip_connect'](C_prev_prev, C, 2, affine, track_running_stats)
else : self.preprocess0 = OPS['nor_conv_1x1'](C_prev_prev, C, 1, affine, track_running_stats)
self.preprocess1 = OPS['nor_conv_1x1'](C_prev, C, 1, affine, track_running_stats)
self._steps = steps
self._multiplier = multiplier
self._ops = nn.ModuleList()
self.edges = nn.ModuleDict()
for i in range(self._steps):
for j in range(2+i):
node_str = '{:}<-{:}'.format(i, j) # indicate the edge from node-(j) to node-(i+2)
stride = 2 if reduction and j < 2 else 1
op = MixedOp(space, C, stride, affine, track_running_stats)
self.edges[ node_str ] = op
self.edge_keys = sorted(list(self.edges.keys()))
self.edge2index = {key:i for i, key in enumerate(self.edge_keys)}
self.num_edges = len(self.edges)
def forward_gdas(self, s0, s1, weightss, indexs):
s0 = self.preprocess0(s0)
s1 = self.preprocess1(s1)
states = [s0, s1]
for i in range(self._steps):
clist = []
for j, h in enumerate(states):
node_str = '{:}<-{:}'.format(i, j)
op = self.edges[ node_str ]
weights = weightss[ self.edge2index[node_str] ]
index = indexs[ self.edge2index[node_str] ].item()
clist.append( op.forward_gdas(h, weights, index) )
states.append( sum(clist) )
return torch.cat(states[-self._multiplier:], dim=1)
def forward_darts(self, s0, s1, weightss):
s0 = self.preprocess0(s0)
s1 = self.preprocess1(s1)
states = [s0, s1]
for i in range(self._steps):
clist = []
for j, h in enumerate(states):
node_str = '{:}<-{:}'.format(i, j)
op = self.edges[ node_str ]
weights = weightss[ self.edge2index[node_str] ]
clist.append( op.forward_darts(h, weights) )
states.append( sum(clist) )
return torch.cat(states[-self._multiplier:], dim=1)