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ResNet18实现

ResNet18实现

作者: 罗泽坤 | 来源:发表于2020-04-18 20:23 被阅读0次
    image.png

    因为本人GPU显存不够就可怜的2G 实在hold不住ResNet 的参数量只好将 残差模块只弄两个卷积核,而且batch_size也修改为1只进行代码测试 - 。 -,听说COLAB上有免费的16G GPU使用下次在运行,由于GPU会进行并行运算这个计算出的显存与实际使用的显存也有点差距。

    import torch
    import torch.nn as nn
    import torch.nn.functional as F
    import torch.optim as optim
    import pickle
    
    # 数据加载
    def load(file):
        with open(file, 'rb') as fo:
            dict = pickle.load(fo, encoding='bytes')
        return dict
    fil_1 = 'E:\Download\DigitalImage\cifar-10-batches-py\data_batch_1'
    fil_2 = 'E:\Download\DigitalImage\cifar-10-batches-py\data_batch_2'
    fil_3 = 'E:\Download\DigitalImage\cifar-10-batches-py\data_batch_3'
    fil_4 = 'E:\Download\DigitalImage\cifar-10-batches-py\data_batch_4'
    fil_5 = 'E:\Download\DigitalImage\cifar-10-batches-py\data_batch_5'
    fil_6 = 'E:\Download\DigitalImage\cifar-10-batches-py\\test_batch_1'
    
    path = [fil_1,fil_2,fil_3,fil_4,fil_5,fil_6]
    train_data = []
    test_data = []
    for i in range(len(path)):
        if i != len(path)-1:
            datas = load(path[i])
            a = datas[b'data'].reshape(10000,3,32,32)
            train_data.append((torch.FloatTensor(a),torch.LongTensor(datas[b'labels'])))
            print()
        else:
            datas = load(path[i])
            test_data = [(torch.FloatTensor(datas[b'data'].reshape(10000,3,32,32)),torch.LongTensor(datas[b'labels']))]
    





    # 残差块定义
    class ResBlock(nn.Module):
        
        
        def __init__(self,in_channel,out_channel,stri):
            super(ResBlock,self).__init__()
            self.cov1 = nn.Conv2d(in_channel,out_channel,kernel_size = 3,stride = stri,padding = 1)
            self.bn1 = nn.BatchNorm2d(out_channel)
            self.cov2 = nn.Conv2d(out_channel,out_channel,kernel_size = 3,stride = 1,padding = 1)
            self.bn2 = nn.BatchNorm2d(out_channel)
            # 恒等映射保证和输出维度一致
            self.identity = nn.Sequential(
                 nn.Conv2d(in_channel,out_channel,kernel_size = 1,stride =stri,padding = 0),
                 nn.BatchNorm2d(out_channel)
                )
        def forward(self,x):
            out = F.relu(self.cov1(x))
            out = self.bn1(out)
            out = F.relu(self.cov2(out))
            out = self.bn2(out)
            #out = F.relu(self.cov2(out))
            #out = self.bn2(out)
            #out = F.relu(self.cov2(out))
            #out = self.bn2(out)
            #print(self.identity(x).shape,out.shape)
            out = self.identity(x) + out
            out = F.relu(out)
            return out
    
    #测试代码输入伪图片
    x = torch.randn(2,3,32,32)
    a = ResBlock(3,64,2)
    print(a(x).shape)
    
    torch.Size([2, 64, 16, 16])
    
    # 残差块网络连接
    class Flatten(nn.Module):
        def __init__(self):
            super(Flatten,self).__init__()
            
        def forward(self,input):
            return input.view(input.size(0),-1)
    
    class Resnet18(nn.Module):
        
        def __init__(self):
            super(Resnet18,self).__init__()
            
            self.model = nn.Sequential(
                nn.Conv2d(3,64,kernel_size = 3,stride = 1,padding = 1),
                nn.BatchNorm2d(64),
                ResBlock(64,128,stri = 2),
                ResBlock(128,256,stri = 2),
                ResBlock(256,512,stri = 2),
                ResBlock(512,1024,stri = 2),
                nn.AvgPool2d(2),
                Flatten(),
                nn.Linear(1024,10)
            ) 
       
        def forward(self,x):
            return self.model(x)
    
    #测试代码
    x = torch.randn(2,3,32,32)
    c = Resnet18()
    print(c(x).shape)
    
    torch.Size([2, 10])
    
    epochs = 10
    device = torch.device('cuda:0')
    ResNet18 = Resnet18().to(device)
    optimizer = optim.SGD(ResNet18.parameters(),lr = 0.01)
    loss_fun = nn.CrossEntropyLoss().to(device)
    
    def Run():
        for epoch in range(epochs):
            ResNet18.train()
            for index,(data,label) in enumerate(train_data):
                for i in range(100):
                    datas = data[i:(i+1),:,:,:].to(device)
                    #print(datas.shape)
                    labels = label[i:(i+1)].to(device)
                    #print(labels.shape)
                    logits = ResNet18(datas)
                    loss = loss_fun(logits,labels)
                    optimizer.zero_grad()
                    loss.backward()
                    optimizer.step()
                print('epoch:{}\t batch:{}\t loss:{}'.format(epoch,index,loss.item()))
            ResNet18.eval()
            loss = 0
            correct = 0
            AVGloss = 0
            for index,(data,label) in enumerate(test_data):
                for i in range(100):
                    datas = data[i:i+1,:,:,:].to(device)
                    labels = label[i:i+1].to(device)
                    logits = ResNet18(datas)
                    loss += loss_fun(logits,labels)
                    predict = logits.argmax(dim=1)
                    correct += predict.eq(labels).float().sum().item()
                loss /= 100.
                print('epochs:{} \t accuracy:{}%\t test_date_AVGloss:{} '.format(epoch,100.*correct/100,loss.item()))
    Run()
    
    epoch:0  batch:0     loss:1.193771243095398
    epoch:0  batch:1     loss:0.6211187839508057
    epoch:0  batch:2     loss:2.3206470012664795
    epoch:0  batch:3     loss:1.0057952404022217
    epoch:0  batch:4     loss:1.6052329540252686
    epochs:0     accuracy:7.0%   test_date_AVGloss:4.08225154876709 
    epoch:1  batch:0     loss:1.168436050415039
    epoch:1  batch:1     loss:0.6469242572784424
    epoch:1  batch:2     loss:1.9090821743011475
    epoch:1  batch:3     loss:0.8259971141815186
    epoch:1  batch:4     loss:1.482107400894165
    epochs:1     accuracy:7.0%   test_date_AVGloss:4.174167633056641 
    epoch:2  batch:0     loss:1.1068801879882812
    epoch:2  batch:1     loss:0.5857620239257812
    epoch:2  batch:2     loss:1.4080276489257812
    epoch:2  batch:3     loss:0.6490111351013184
    epoch:2  batch:4     loss:1.3858662843704224
    epochs:2     accuracy:7.0%   test_date_AVGloss:4.06494140625 
    epoch:3  batch:0     loss:0.7395391464233398
    epoch:3  batch:1     loss:0.5753352642059326
    epoch:3  batch:2     loss:1.252335786819458
    epoch:3  batch:3     loss:0.41171860694885254
    epoch:3  batch:4     loss:1.258840560913086
    epochs:3     accuracy:10.0%  test_date_AVGloss:3.6299731731414795 
    epoch:4  batch:0     loss:0.5887634754180908
    epoch:4  batch:1     loss:0.5793724060058594
    epoch:4  batch:2     loss:1.1198831796646118
    epoch:4  batch:3     loss:0.300403356552124
    epoch:4  batch:4     loss:0.7450690269470215
    epochs:4     accuracy:14.0%  test_date_AVGloss:3.8890163898468018 
    epoch:5  batch:0     loss:0.24598288536071777
    epoch:5  batch:1     loss:0.16252756118774414
    epoch:5  batch:2     loss:0.6145534515380859
    epoch:5  batch:3     loss:0.1928553581237793
    epoch:5  batch:4     loss:0.20372629165649414
    epochs:5     accuracy:18.0%  test_date_AVGloss:3.09653377532959 
    epoch:6  batch:0     loss:0.07158946990966797
    epoch:6  batch:1     loss:0.2547154426574707
    epoch:6  batch:2     loss:0.2163069248199463
    epoch:6  batch:3     loss:0.1844019889831543
    epoch:6  batch:4     loss:0.12868928909301758
    epochs:6     accuracy:23.0%  test_date_AVGloss:2.7130041122436523 
    epoch:7  batch:0     loss:0.04795646667480469
    epoch:7  batch:1     loss:0.053249359130859375
    epoch:7  batch:2     loss:0.02186727523803711
    epoch:7  batch:3     loss:0.032016754150390625
    epoch:7  batch:4     loss:0.02663278579711914
    epochs:7     accuracy:23.0%  test_date_AVGloss:2.557596445083618 
    epoch:8  batch:0     loss:0.03522920608520508
    epoch:8  batch:1     loss:0.03684282302856445
    epoch:8  batch:2     loss:0.014127731323242188
    epoch:8  batch:3     loss:0.018548965454101562
    epoch:8  batch:4     loss:0.019474029541015625
    epochs:8     accuracy:21.0%  test_date_AVGloss:2.537302255630493 
    epoch:9  batch:0     loss:0.01775217056274414
    epoch:9  batch:1     loss:0.023839473724365234
    epoch:9  batch:2     loss:0.011283397674560547
    epoch:9  batch:3     loss:0.014598846435546875
    epoch:9  batch:4     loss:0.014908790588378906
    epochs:9     accuracy:25.0%  test_date_AVGloss:2.5501718521118164 
    
    print(len(test_data))
    
    1
    
    # 参数字节数
    byte = (9*(3*64+64*64+64*128+128*128+128*256+256*256+256*512+512*512+512*1024+1024*1024)+1024*10)*4
    # SGD
    sgd_byte = byte
    # 保存梯度字节数
    print(byte)
    grad = byte
    # 输入输出显存
    put = (3*32*32+32*32*64+64*16*16+128*8*8+256*4*4+512*2*2+1024)*4
    print((byte*3+put)/1000000)
    
    75397888
    226.595072
    
    
    

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