update CVPR-2019-GDAS re-train NASNet-search-space searched models

lib/models/cell_infers/nasnet_cifar.py

@@ -0,0 +1,71 @@
+#####################################################
+# Copyright (c) Xuanyi Dong [GitHub D-X-Y], 2019.01 #
+#####################################################
+import torch
+import torch.nn as nn
+from copy import deepcopy
+from .cells import NASNetInferCell as InferCell, AuxiliaryHeadCIFAR
+
+
+# The macro structure is based on NASNet
+class NASNetonCIFAR(nn.Module):
+
+  def __init__(self, C, N, stem_multiplier, num_classes, genotype, auxiliary, affine=True, track_running_stats=True):
+    super(NASNetonCIFAR, self).__init__()
+    self._C        = C
+    self._layerN   = N
+    self.stem = nn.Sequential(
+                    nn.Conv2d(3, C*stem_multiplier, kernel_size=3, padding=1, bias=False),
+                    nn.BatchNorm2d(C*stem_multiplier))
+  
+    # config for each layer
+    layer_channels   = [C    ] * N + [C*2 ] + [C*2  ] * (N-1) + [C*4 ] + [C*4  ] * (N-1)
+    layer_reductions = [False] * N + [True] + [False] * (N-1) + [True] + [False] * (N-1)
+
+    C_prev_prev, C_prev, C_curr, reduction_prev = C*stem_multiplier, C*stem_multiplier, C, False
+    self.auxiliary_index = None
+    self.auxiliary_head  = None
+    self.cells = nn.ModuleList()
+    for index, (C_curr, reduction) in enumerate(zip(layer_channels, layer_reductions)):
+      cell = InferCell(genotype, C_prev_prev, C_prev, C_curr, reduction, reduction_prev, affine, track_running_stats)
+      self.cells.append( cell )
+      C_prev_prev, C_prev, reduction_prev = C_prev, cell._multiplier*C_curr, reduction
+      if reduction and C_curr == C*4 and auxiliary:
+        self.auxiliary_head = AuxiliaryHeadCIFAR(C_prev, num_classes)
+        self.auxiliary_index = index
+    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.drop_path_prob = -1
+
+  def update_drop_path(self, drop_path_prob):
+    self.drop_path_prob = drop_path_prob
+
+  def auxiliary_param(self):
+    if self.auxiliary_head is None: return []
+    else: return list( self.auxiliary_head.parameters() )
+
+  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):
+    stem_feature, logits_aux = self.stem(inputs), None
+    cell_results = [stem_feature, stem_feature]
+    for i, cell in enumerate(self.cells):
+      cell_feature = cell(cell_results[-2], cell_results[-1], self.drop_path_prob)
+      cell_results.append( cell_feature )
+      if self.auxiliary_index is not None and i == self.auxiliary_index and self.training:
+        logits_aux = self.auxiliary_head( cell_results[-1] )
+    out = self.lastact(cell_results[-1])
+    out = self.global_pooling( out )
+    out = out.view(out.size(0), -1)
+    logits = self.classifier(out)
+    if logits_aux is None: return out, logits
+    else: return out, [logits, logits_aux]