知识要点
- FashionMNIST数据集: 十种产品的分类. # T-shirt/top, Trouser, Pullover, Dress, Coat,Sandal, Shirt, Sneaker, Bag, Ankle Boot.
- writer = SummaryWriter('run/fashion_mnist_experiment_1') # 网站显示
一 tensorboard的使用

1.1 导包
import matplotlib.pyplot as plt
import numpy as np
import torch
import torchvision
import torchvision.transforms as transforms
import torch.nn as nn
import torch.nn.functional as F
import torch.optim as optim
1.2 数据导入
# transforms
transform = transforms.Compose([transforms.ToTensor(),transforms.Normalize((0.5, ), (0.5))]) # 正则化# datasets
trainset = torchvision.datasets.FashionMNIST('./data',download=True,train=True,transform = transform)testset = torchvision.datasets.FashionMNIST('./data',download=True,train=False,transform = transform)
# dataloaders
trainloader = torch.utils.data.DataLoader(trainset, batch_size=4, shuffle=True, num_workers=2)
testloader = torch.utils.data.DataLoader(testset, batch_size=4, shuffle=True, num_workers=2)# constant for classes
classes = ('T-shirt/top', 'Trouser', 'Pullover', 'Dress', 'Coat','Sandal', 'Shirt', 'Sneaker', 'Bag', 'Ankle Boot')
1.3 定义模型
# 定义模型
class Net(nn.Module):def __init__(self):super(Net, self).__init__()self.conv1 = nn.Conv2d(1, 6, 5)self.pool = nn.MaxPool2d(2, 2)self.conv2 = nn.Conv2d(6, 16, 5)self.fc1 = nn.Linear(16 * 4 * 4, 120)self.fc2 = nn.Linear(120, 84)self.fc3 = nn.Linear(84, 10)def forward(self, x):x = self.pool(F.relu(self.conv1(x)))x = self.pool(F.relu(self.conv2(x)))x = x.view(-1, 16 * 4 * 4)x = F.relu(self.fc1(x))x = F.relu(self.fc2(x))x = self.fc3(x)return xnet = Net()
# 定义损失和优化器
criterion = nn.CrossEntropyLoss()
optimizer = optim.SGD(net.parameters(), lr = 0.001, momentum=0.9)
1.4 tensorboard的使用
- tensorboard的安装: pip install tensorboard -i https://pypi.douban.com/simple
def matplotlib_imshow(img, one_channel=False):if one_channel:img = img.mean(dim=0)img = img / 2 + 0.5npimg = img.numpy()if one_channel:plt.imshow(npimg, cmap= 'Greys')else:plt.imshow(np.transpose(npimg, (1, 2, 0)))
dataiter = iter(trainloader)
images, labels = next(dataiter)
images.shape # torch.Size([4, 1, 28, 28])
# torchvision 中make_grid 可以把多张图合并成一张图
img_grid = torchvision.utils.make_grid(images)
img_grid.shape # torch.Size([3, 32, 122])
matplotlib_imshow(img_grid, one_channel=True)

- from torch.utils.tensorboard import SummaryWriter
writer = SummaryWriter('run/fashion_mnist_experiment_1')
writer.add_image('four_fashion_mnist_images', img_grid)images, labels = next(dataiter)
img_grid2 = torchvision.utils.make_grid(images)
matplotlib_imshow(img_grid2, one_channel=True)

writer.add_image('img_grid2', img_grid2)
1.5 添加模型的结构图
writer.add_graph(net, images) # 模型可视化
1.6 添加损失变化
# writer.add_scaler()
running_loss = 0.0
for epoch in range(1): # loop over the dataset multiple timesfor i, data in enumerate(trainloader, 0):# get the inputs: data is list of [inputs, labels]inputs, labels = data# zero the parameter gradientsoptimizer.zero_grad()# forward + backward + optimizeoutputs = net(inputs)loss = criterion(outputs, labels)loss.backward()optimizer.step()running_loss += loss.item()if i % 1000 == 999: # every 1000 mini-batches...# log the running losswriter.add_scalar('training loss',running_loss / 1000,epoch * len(trainloader) + i)running_loss = 0.0
print('Finished Training')