13.使用NiN网络进行Fashion-Mnist分类

13.1 NiN网络结构设计

import torch
from torch import nn
import matplotlib.pyplot as plt
from torchsummary import summarydef nin_block(in_channels, out_channels, kernel_size, strides, padding):return nn.Sequential(nn.Conv2d(in_channels, out_channels, kernel_size, strides, padding),nn.ReLU(),nn.Conv2d(out_channels, out_channels, kernel_size=1), nn.ReLU(),nn.Conv2d(out_channels, out_channels, kernel_size=1), nn.ReLU())
model= nn.Sequential(nin_block(1, 96, kernel_size=11, strides=4, padding=0),nn.MaxPool2d(3, stride=2),nin_block(96, 256, kernel_size=5, strides=1, padding=2),nn.MaxPool2d(3, stride=2),nin_block(256, 384, kernel_size=3, strides=1, padding=1),nn.MaxPool2d(3, stride=2),nn.Dropout(0.5),# 标签类别数是10nin_block(384, 10, kernel_size=3, strides=1, padding=1),nn.AdaptiveAvgPool2d((1, 1)),# 将四维的输出转成二维的输出，其形状为(批量大小,10)nn.Flatten())
device=torch.device("cuda" if torch.cuda.is_available() else 'cpu')
model.to(device)
summary(model,input_size=(1,224,224),batch_size=1)

13.2 NiN网络实现Fashion-Mnist分类

import torch
import torchvision
from torch import nn
import matplotlib.pyplot as plt
from torchvision.transforms import transforms
from torch.utils.data import DataLoader
from tqdm import tqdm
from sklearn.metrics import accuracy_score
plt.rcParams['font.family']=['Times New Roman']
def nin_block(in_channels, out_channels, kernel_size, strides, padding):return nn.Sequential(nn.Conv2d(in_channels, out_channels, kernel_size, strides, padding),nn.ReLU(),nn.Conv2d(out_channels, out_channels, kernel_size=1), nn.ReLU(),nn.Conv2d(out_channels, out_channels, kernel_size=1), nn.ReLU())
def plot_metrics(train_loss_list, train_acc_list, test_acc_list, title='Training Curve'):epochs = range(1, len(train_loss_list) + 1)plt.figure(figsize=(4, 3))plt.plot(epochs, train_loss_list, label='Train Loss')plt.plot(epochs, train_acc_list, label='Train Acc',linestyle='--')plt.plot(epochs, test_acc_list, label='Test Acc', linestyle='--')plt.xlabel('Epoch')plt.ylabel('Value')plt.title(title)plt.legend()plt.grid(True)plt.tight_layout()plt.show()
def train_model(model,train_data,test_data,num_epochs):train_loss_list = []train_acc_list = []test_acc_list = []for epoch in range(num_epochs):total_loss=0total_acc_sample=0total_samples=0#loop=tqdm(train_data,desc=f"EPOCHS[{epoch+1}/{num_epochs}]")loop1=tqdm(train_data,desc=f"EPOCHS[{epoch+1}/{num_epochs}]")loop2=tqdm(test_data,desc=f"EPOCHS[{epoch+1}/{num_epochs}]")for X,y in loop1:#X=X.reshape(X.shape[0],-1)#print(X.shape)X=X.to(device)y=y.to(device)y_hat=model(X)loss=CEloss(y_hat,y)optimizer.zero_grad()loss.backward()optimizer.step()#loss累加total_loss+=loss.item()*X.shape[0]y_pred=y_hat.argmax(dim=1).detach().cpu().numpy()y_true=y.detach().cpu().numpy()total_acc_sample+=accuracy_score(y_pred,y_true)*X.shape[0]#保存样本数total_samples+=X.shape[0]test_acc_samples=0test_samples=0for X,y in loop2:X=X.to(device)y=y.to(device)#X=X.reshape(X.shape[0],-1)y_hat=model(X)y_pred=y_hat.argmax(dim=1).detach().cpu().numpy()y_true=y.detach().cpu().numpy()test_acc_samples+=accuracy_score(y_pred,y_true)*X.shape[0]#保存样本数test_samples+=X.shape[0]avg_train_loss=total_loss/total_samplesavg_train_acc=total_acc_sample/total_samplesavg_test_acc=test_acc_samples/test_samplestrain_loss_list.append(avg_train_loss)train_acc_list.append(avg_train_acc)test_acc_list.append(avg_test_acc)print(f"Epoch {epoch+1}: Loss: {avg_train_loss:.4f},Trian Accuracy: {avg_train_acc:.4f},test Accuracy: {avg_test_acc:.4f}")plot_metrics(train_loss_list, train_acc_list, test_acc_list)return model
def init_weights(m):if type(m) == nn.Linear or type(m) == nn.Conv2d:nn.init.xavier_uniform_(m.weight)
################################################################################################################
#注意这里从28*28 resize成224*224了
transforms=transforms.Compose([transforms.Resize(224),transforms.ToTensor(),transforms.Normalize((0.5,),(0.5,))])#第一个是mean,第二个是std
train_img=torchvision.datasets.FashionMNIST(root="./data",train=True,transform=transforms,download=True)
test_img=torchvision.datasets.FashionMNIST(root="./data",train=False,transform=transforms,download=True)
train_data=DataLoader(train_img,batch_size=256,num_workers=4,shuffle=True)
test_data=DataLoader(test_img,batch_size=256,num_workers=4,shuffle=False)
################################################################################################################
model = nn.Sequential(nin_block(1, 32, kernel_size=5, strides=1, padding=2),nn.MaxPool2d(2),nin_block(32, 64, kernel_size=3, strides=1, padding=1),nn.MaxPool2d(2),nin_block(64, 10, kernel_size=3, strides=1, padding=1),nn.AdaptiveAvgPool2d((1, 1)),nn.Flatten())
model.apply(init_weights)
device=torch.device("cuda:1" if torch.cuda.is_available() else "cpu")
#print(device)
model=model.to(device)
optimizer=torch.optim.SGD(model.parameters(),lr=0.1,momentum=0.9)
CEloss=nn.CrossEntropyLoss()
num_epochs=20
model=train_model(model,train_data,test_data,num_epochs)