Graph U-Net Code【图分类】

1. main.py

# GNet是需要用到的model
net = GNet(G_data.feat_dim, G_data.num_class, args) # graph, 特征维度，类别数，参数
trainer = Trainer(args, net, G_data) #开始训练数据
# 正式开始训练数据
trainer.train()

2. network.py

class GNet(nn.Module):
    def __init__(self, in_dim, n_classes, args):
        super(GNet, self).__init__()
        self.n_act = getattr(nn, args.act_n)()# getattr() 是 Python 内置的一个函数，可以用来获取一个对象的属性值或方法
        self.c_act = getattr(nn, args.act_c)()# print('GNet1: in_dim=', in_dim, 'n_class=',n_classes)  # GNet1: in_dim= 82 n_class= 2

        "用的是GCN的框架，输入分别是feat dim、layer dim、network act、drop net（net表示GCN网络本身的参数）"
        self.s_gcn = GCN(in_dim, args.l_dim, self.n_act, args.drop_n)
        self.g_unet = GraphUnet(args.ks, args.l_dim, args.l_dim, args.l_dim, self.n_act, args.drop_n)

        """nn.Linear定义一个神经网络的线性层，方法如下：
           torch.nn.Linear(in_features, # 输入的神经元个数
           out_features, # 输出神经元个数
           bias=True # 是否包含偏置)"""
        self.out_l_1 = nn.Linear(3*args.l_dim*(args.l_num+1), args.h_dim)
        self.out_l_2 = nn.Linear(args.h_dim, n_classes)

        "nn.Dropout(p = 0.3) # 表示每个神经元有0.3的可能性不被激活"
        self.out_drop = nn.Dropout(p=args.drop_c)
        Initializer.weights_init(self)

    def forward(self, gs, hs, labels):
        print('GNet2: gs=',type(gs), len(gs), 'hs=',type(hs), len(hs), 'labels:',type(labels),labels.shape)
        # GNet2: gs= <class 'list'> 32 hs= <class 'list'> 32 labels: <class 'torch.Tensor'> torch.Size([32])
        hs = self.embed(gs, hs)
        print('GNet2: hs=', type(hs), hs.shape)
        logits = self.classify(hs)
        return self.metric(logits, labels)

3. trainer.py

class Trainer:
    "init初始化，输入分别是arg参数、gcn net、graph Data，将这些装进self里面"
    def __init__(self, args, net, G_data):
        self.args = args
        self.net = net
        self.feat_dim = G_data.feat_dim
        self.fold_idx = G_data.fold_idx
        self.init(args, G_data.train_gs, G_data.test_gs)
        # 若是有显卡，则用显卡跑
        if torch.cuda.is_available():
            self.net.cuda()

    "初始化------开始训练数据"
    def init(self, args, train_gs, test_gs):
        print('#train: %d, #test: %d' % (len(train_gs), len(test_gs)))
        # 分成训练集和测试集，记载数据
        train_data = GraphData(train_gs, self.feat_dim)
        test_data = GraphData(test_gs, self.feat_dim)

        # DataLoader 为pytorch 内部类，此时只需要指定trainset， batch_size， shuffle， num_workers, ...等
        self.train_d = train_data.loader(self.args.batch, True)
        self.test_d = test_data.loader(self.args.batch, False)
        self.optimizer = optim.Adam(
            self.net.parameters(), lr=self.args.lr, amsgrad=True,
            weight_decay=0.0008)

    def train(self):
        max_acc = 0.0
        train_str = 'Train epoch %d: loss %.5f acc %.5f'
        test_str = 'Test epoch %d: loss %.5f acc %.5f max %.5f'
        line_str = '%d:\t%.5f\n'
        for e_id in range(self.args.num_epochs):
            self.net.train()

            # 从每个epoch开始训练
            loss, acc = self.run_epoch(e_id, self.train_d, self.net, self.optimizer)
            print(train_str % (e_id, loss, acc))

            with torch.no_grad():
                self.net.eval()
                loss, acc = self.run_epoch(e_id, self.test_d, self.net, None)
            max_acc = max(max_acc, acc)
            print(test_str % (e_id, loss, acc, max_acc))

        with open(self.args.acc_file, 'a+') as f:
            f.write(line_str % (self.fold_idx, max_acc))

    def run_epoch(self, epoch, data, model, optimizer):

        #self.run_epoch(e_id, self.train_d, self.net, self.optimizer)
        losses, accs, n_samples = [], [], 0
        for batch in tqdm(data, desc=str(epoch), unit='b'):
            cur_len, gs, hs, ys = batch
            gs, hs, ys = map(self.to_cuda, [gs, hs, ys])
            loss, acc = model(gs, hs, ys)

            losses.append(loss*cur_len)
            accs.append(acc*cur_len)
            n_samples += cur_len
            if optimizer is not None:
                optimizer.zero_grad()
                loss.backward()
                optimizer.step()

        avg_loss, avg_acc = sum(losses) / n_samples, sum(accs) / n_samples
        return avg_loss.item(), avg_acc.item()

不懂

class GraphConvolution(Module):
    """
    Simple GCN layer, similar to https://arxiv.org/abs/1609.02907
    """

    def __init__(self, in_features, out_features, bias=True):
        super(GraphConvolution, self).__init__()
        self.in_features = in_features
        self.out_features = out_features
        """为啥要这么做？？？5555555555555555555555555555"""
        self.weight = Parameter(torch.FloatTensor(in_features, out_features))
        if bias:
            self.bias = Parameter(torch.FloatTensor(out_features))
        else:
            self.register_parameter('bias', None)
        self.reset_parameters()

    def reset_parameters(self):
        stdv = 1. / math.sqrt(self.weight.size(1))
        self.weight.data.uniform_(-stdv, stdv)
        if self.bias is not None:
            self.bias.data.uniform_(-stdv, stdv)

    def forward(self, input, adj):
 
        support = torch.mm(input, self.weight)
        output = torch.spmm(adj, support)
        if self.bias is not None:
            return output + self.bias
        else:
            return output