update

nasbench201/cell_infers/cells.py

@@ -0,0 +1,120 @@
+#####################################################
+# Copyright (c) Xuanyi Dong [GitHub D-X-Y], 2019.01 #
+#####################################################
+
+import torch
+import torch.nn as nn
+from copy import deepcopy
+from ..cell_operations import OPS
+
+
+# Cell for NAS-Bench-201
+class InferCell(nn.Module):
+
+  def __init__(self, genotype, C_in, C_out, stride):
+    super(InferCell, self).__init__()
+
+    self.layers  = nn.ModuleList()
+    self.node_IN = []
+    self.node_IX = []
+    self.genotype = deepcopy(genotype)
+    for i in range(1, len(genotype)):
+      node_info = genotype[i-1]
+      cur_index = []
+      cur_innod = []
+      for (op_name, op_in) in node_info:
+        if op_in == 0:
+          layer = OPS[op_name](C_in , C_out, stride, True, True)
+        else:
+          layer = OPS[op_name](C_out, C_out,      1, True, True)
+        cur_index.append( len(self.layers) )
+        cur_innod.append( op_in )
+        self.layers.append( layer )
+      self.node_IX.append( cur_index )
+      self.node_IN.append( cur_innod )
+    self.nodes   = len(genotype)
+    self.in_dim  = C_in
+    self.out_dim = C_out
+
+  def extra_repr(self):
+    string = 'info :: nodes={nodes}, inC={in_dim}, outC={out_dim}'.format(**self.__dict__)
+    laystr = []
+    for i, (node_layers, node_innods) in enumerate(zip(self.node_IX,self.node_IN)):
+      y = ['I{:}-L{:}'.format(_ii, _il) for _il, _ii in zip(node_layers, node_innods)]
+      x = '{:}<-({:})'.format(i+1, ','.join(y))
+      laystr.append( x )
+    return string + ', [{:}]'.format( ' | '.join(laystr) ) + ', {:}'.format(self.genotype.tostr())
+
+  def forward(self, inputs):
+    nodes = [inputs]
+    for i, (node_layers, node_innods) in enumerate(zip(self.node_IX,self.node_IN)):
+      node_feature = sum( self.layers[_il](nodes[_ii]) for _il, _ii in zip(node_layers, node_innods) )
+      nodes.append( node_feature )
+    return nodes[-1]
+
+
+
+# Learning Transferable Architectures for Scalable Image Recognition, CVPR 2018
+class NASNetInferCell(nn.Module):
+
+  def __init__(self, genotype, C_prev_prev, C_prev, C, reduction, reduction_prev, affine, track_running_stats):
+    super(NASNetInferCell, self).__init__()
+    self.reduction = reduction
+    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)
+
+    if not reduction:
+      nodes, concats = genotype['normal'], genotype['normal_concat']
+    else:
+      nodes, concats = genotype['reduce'], genotype['reduce_concat']
+    self._multiplier = len(concats)
+    self._concats = concats
+    self._steps = len(nodes)
+    self._nodes = nodes
+    self.edges = nn.ModuleDict()
+    for i, node in enumerate(nodes):
+      for in_node in node:
+        name, j = in_node[0], in_node[1]
+        stride = 2 if reduction and j < 2 else 1
+        node_str = '{:}<-{:}'.format(i+2, j)
+        self.edges[node_str] = OPS[name](C, C, stride, affine, track_running_stats)
+
+  # [TODO] to support drop_prob in this function..
+  def forward(self, s0, s1, unused_drop_prob):
+    s0 = self.preprocess0(s0)
+    s1 = self.preprocess1(s1)
+
+    states = [s0, s1]
+    for i, node in enumerate(self._nodes):
+      clist = []
+      for in_node in node:
+        name, j = in_node[0], in_node[1]
+        node_str = '{:}<-{:}'.format(i+2, j)
+        op = self.edges[ node_str ]
+        clist.append( op(states[j]) )
+      states.append( sum(clist) )
+    return torch.cat([states[x] for x in self._concats], dim=1)
+
+
+class AuxiliaryHeadCIFAR(nn.Module):
+
+  def __init__(self, C, num_classes):
+    """assuming input size 8x8"""
+    super(AuxiliaryHeadCIFAR, self).__init__()
+    self.features = nn.Sequential(
+      nn.ReLU(inplace=True),
+      nn.AvgPool2d(5, stride=3, padding=0, count_include_pad=False), # image size = 2 x 2
+      nn.Conv2d(C, 128, 1, bias=False),
+      nn.BatchNorm2d(128),
+      nn.ReLU(inplace=True),
+      nn.Conv2d(128, 768, 2, bias=False),
+      nn.BatchNorm2d(768),
+      nn.ReLU(inplace=True)
+    )
+    self.classifier = nn.Linear(768, num_classes)
+
+  def forward(self, x):
+    x = self.features(x)
+    x = self.classifier(x.view(x.size(0),-1))
+    return x

nasbench201/cell_infers/tiny_network.py

@@ -0,0 +1,82 @@
+#####################################################
+# Copyright (c) Xuanyi Dong [GitHub D-X-Y], 2019.01 #
+#####################################################
+import torch.nn as nn
+from ..cell_operations import ResNetBasicblock
+from .cells import InferCell
+
+
+# The macro structure for architectures in NAS-Bench-201
+class TinyNetwork(nn.Module):
+
+  def __init__(self, C, N, genotype, num_classes):
+    super(TinyNetwork, self).__init__()
+    self._C               = C
+    self._layerN          = N
+
+    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 = C
+    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, True)
+      else:
+        cell = InferCell(genotype, C_prev, C_curr, 1)
+      self.cells.append( cell )
+      C_prev = cell.out_dim
+    self._Layer= len(self.cells)
+
+    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.requires_feature = True
+
+  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}, N={_layerN}, L={_Layer})'.format(name=self.__class__.__name__, **self.__dict__))
+
+  def forward(self, inputs):
+    feature = self.stem(inputs)
+    for i, cell in enumerate(self.cells):
+      feature = cell(feature)
+
+    out = self.lastact(feature)
+    out = self.global_pooling( out )
+    out = out.view(out.size(0), -1)
+    logits = self.classifier(out)
+
+    if self.requires_feature:
+      return logits, out
+    else:
+      return logits
+  
+  def _loss(self, input, target, return_logits=False):
+    logits, _ = self(input)
+    loss = self._criterion(logits, target)
+    
+    return (loss, logits) if return_logits else loss
+
+  def step(self, input, target, args, shared=None, return_grad=False):
+    Lt, logit_t = self._loss(input, target, return_logits=True)
+    Lt.backward()
+    if args.grad_clip != 0: 
+      nn.utils.clip_grad_norm_(self.get_weights(), args.grad_clip)
+    self.optimizer.step()
+
+    if return_grad:
+      grad = torch.nn.utils.parameters_to_vector([p.grad for p in self.get_weights()])
+      return logit_t, Lt, grad
+    else:
+      return logit_t, Lt