import torch
import torch.nn.functional as F
import torch
import torch.nn as nn
import torch.nn.functional as F
import torch.optim as optim
from torchvision import datasets, transforms
#超参数
batch_size=200
learning_rate=0.01
epochs=10
#获取训练数据
train_loader = torch.utils.data.DataLoader(
datasets.MNIST('../data', train=True, download=True, #train=True则得到的是训练集
transform=transforms.Compose([ #transform进行数据预处理
transforms.ToTensor(), #转成Tensor类型的数据
transforms.Normalize((0.1307,), (0.3081,)) #进行数据标准化(减去均值除以方差)
])),
batch_size=batch_size, shuffle=True) #按batch_size分出一个batch维度在最前面,shuffle=True打乱顺序
#获取测试数据
test_loader = torch.utils.data.DataLoader(
datasets.MNIST('../data', train=False, transform=transforms.Compose([
transforms.ToTensor(),
transforms.Normalize((0.1307,), (0.3081,))
])),
batch_size=batch_size, shuffle=True)
class MLP(nn.Module):
def __init__(self):
super(MLP, self).__init__()
self.model = nn.Sequential( #定义网络的每一层,nn.ReLU可以换成其他激活函数,比如nn.LeakyReLU()
nn.Linear(784, 200),
nn.ReLU(inplace=True),
nn.Linear(200, 200),
nn.ReLU(inplace=True),
nn.Linear(200, 10),
nn.ReLU(inplace=True),
)
def forward(self, x):
x = self.model(x)
return x
net = MLP()
#定义sgd优化器,指明优化参数、学习率,net.parameters()得到这个类所定义的网络的参数[[w1,b1,w2,b2,...]
optimizer = optim.SGD(net.parameters(), lr=learning_rate)
criteon = nn.CrossEntropyLoss()
for epoch in range(epochs):
for batch_idx, (data, target) in enumerate(train_loader):
data = data.view(-1, 28*28) #将二维的图片数据摊平[样本数,784]
logits = net(data) #前向传播
loss = criteon(logits, target) #nn.CrossEntropyLoss()自带Softmax
optimizer.zero_grad() #梯度信息清空
loss.backward() #反向传播获取梯度
optimizer.step() #优化器更新
if batch_idx % 100 == 0: #每100个batch输出一次信息
print('Train Epoch: {} [{}/{} ({:.0f}%)]\tLoss: {:.6f}'.format(
epoch, batch_idx * len(data), len(train_loader.dataset),
100. * batch_idx / len(train_loader), loss.item()))
test_loss = 0
correct = 0 #correct记录正确分类的样本数
for data, target in test_loader:
data = data.view(-1, 28 * 28)
logits = net(data)
test_loss += criteon(logits, target).item() #其实就是criteon(logits, target)的值,标量
pred = logits.data.max(dim=1)[1] #也可以写成pred=logits.argmax(dim=1)
correct += pred.eq(target.data).sum()
test_loss /= len(test_loader.dataset)
print('\nTest set: Average loss: {:.4f}, Accuracy: {}/{} ({:.0f}%)\n'.format(
test_loss, correct, len(test_loader.dataset),
100. * correct / len(test_loader.dataset)))
C:\Users\ygx79\AppData\Local\Programs\Python\Python37\lib\site-packages\torchvision\io\image.py:11: UserWarning: Failed to load image Python extension: [WinError 126] 找不到指定的模块。
warn(f"Failed to load image Python extension: {e}")
Downloading http://yann.lecun.com/exdb/mnist/train-images-idx3-ubyte.gz
Downloading http://yann.lecun.com/exdb/mnist/train-images-idx3-ubyte.gz to ../data\MNIST\raw\train-images-idx3-ubyte.gz
9913344it [09:45, 16922.35it/s]
Extracting ../data\MNIST\raw\train-images-idx3-ubyte.gz to ../data\MNIST\raw
Downloading http://yann.lecun.com/exdb/mnist/train-labels-idx1-ubyte.gz
Downloading http://yann.lecun.com/exdb/mnist/train-labels-idx1-ubyte.gz to ../data\MNIST\raw\train-labels-idx1-ubyte.gz
29696it [00:00, 112126.01it/s]
Extracting ../data\MNIST\raw\train-labels-idx1-ubyte.gz to ../data\MNIST\raw
Downloading http://yann.lecun.com/exdb/mnist/t10k-images-idx3-ubyte.gz
Downloading http://yann.lecun.com/exdb/mnist/t10k-images-idx3-ubyte.gz to ../data\MNIST\raw\t10k-images-idx3-ubyte.gz
1649664it [00:06, 236143.14it/s]
Extracting ../data\MNIST\raw\t10k-images-idx3-ubyte.gz to ../data\MNIST\raw
Downloading http://yann.lecun.com/exdb/mnist/t10k-labels-idx1-ubyte.gz
Downloading http://yann.lecun.com/exdb/mnist/t10k-labels-idx1-ubyte.gz to ../data\MNIST\raw\t10k-labels-idx1-ubyte.gz
5120it [00:00, ?it/s]
Extracting ../data\MNIST\raw\t10k-labels-idx1-ubyte.gz to ../data\MNIST\raw
Train Epoch: 0 [0/60000 (0%)] Loss: 2.307192
Train Epoch: 0 [20000/60000 (33%)] Loss: 2.138816
Train Epoch: 0 [40000/60000 (67%)] Loss: 1.768016
Test set: Average loss: 0.0070, Accuracy: 6058/10000 (61%)
Train Epoch: 1 [0/60000 (0%)] Loss: 1.505597
Train Epoch: 1 [20000/60000 (33%)] Loss: 1.149395
Train Epoch: 1 [40000/60000 (67%)] Loss: 1.039293
Test set: Average loss: 0.0047, Accuracy: 7143/10000 (71%)
Train Epoch: 2 [0/60000 (0%)] Loss: 1.061429
Train Epoch: 2 [20000/60000 (33%)] Loss: 0.741140
Train Epoch: 2 [40000/60000 (67%)] Loss: 0.901448
Test set: Average loss: 0.0041, Accuracy: 7299/10000 (73%)
Train Epoch: 3 [0/60000 (0%)] Loss: 0.809117
Train Epoch: 3 [20000/60000 (33%)] Loss: 0.892138
Train Epoch: 3 [40000/60000 (67%)] Loss: 0.659411
Test set: Average loss: 0.0030, Accuracy: 8170/10000 (82%)
Train Epoch: 4 [0/60000 (0%)] Loss: 0.622007
Train Epoch: 4 [20000/60000 (33%)] Loss: 0.592337
Train Epoch: 4 [40000/60000 (67%)] Loss: 0.445400
Test set: Average loss: 0.0027, Accuracy: 8225/10000 (82%)
Train Epoch: 5 [0/60000 (0%)] Loss: 0.519135
Train Epoch: 5 [20000/60000 (33%)] Loss: 0.491247
Train Epoch: 5 [40000/60000 (67%)] Loss: 0.562315
Test set: Average loss: 0.0026, Accuracy: 8295/10000 (83%)
Train Epoch: 6 [0/60000 (0%)] Loss: 0.509583
Train Epoch: 6 [20000/60000 (33%)] Loss: 0.553628
Train Epoch: 6 [40000/60000 (67%)] Loss: 0.484189
Test set: Average loss: 0.0025, Accuracy: 8336/10000 (83%)
Train Epoch: 7 [0/60000 (0%)] Loss: 0.619250
Train Epoch: 7 [20000/60000 (33%)] Loss: 0.634936
Train Epoch: 7 [40000/60000 (67%)] Loss: 0.440220
Test set: Average loss: 0.0024, Accuracy: 8370/10000 (84%)
Train Epoch: 8 [0/60000 (0%)] Loss: 0.410350
Train Epoch: 8 [20000/60000 (33%)] Loss: 0.460459
Train Epoch: 8 [40000/60000 (67%)] Loss: 0.395150
Test set: Average loss: 0.0024, Accuracy: 8395/10000 (84%)
Train Epoch: 9 [0/60000 (0%)] Loss: 0.515630
Train Epoch: 9 [20000/60000 (33%)] Loss: 0.546718
Train Epoch: 9 [40000/60000 (67%)] Loss: 0.496167
Test set: Average loss: 0.0023, Accuracy: 8433/10000 (84%)
device = torch.device('cuda:0')
net = MLP().to(device)
#定义sgd优化器,指明优化参数、学习率,net.parameters()得到这个类所定义的网络的参数[[w1,b1,w2,b2,...]
optimizer = optim.SGD(net.parameters(), lr=learning_rate)
criteon = nn.CrossEntropyLoss().to(device)
GPU acc
import torch
import torch.nn as nn
import torch.nn.functional as F
import torch.optim as optim
from torchvision import datasets, transforms
#超参数
batch_size=200
learning_rate=0.01
epochs=10
#获取训练数据
train_loader = torch.utils.data.DataLoader(
datasets.MNIST('../data', train=True, download=True, #train=True则得到的是训练集
transform=transforms.Compose([ #transform进行数据预处理
transforms.ToTensor(), #转成Tensor类型的数据
transforms.Normalize((0.1307,), (0.3081,)) #进行数据标准化(减去均值除以方差)
])),
batch_size=batch_size, shuffle=True) #按batch_size分出一个batch维度在最前面,shuffle=True打乱顺序
#获取测试数据
test_loader = torch.utils.data.DataLoader(
datasets.MNIST('../data', train=False, transform=transforms.Compose([
transforms.ToTensor(),
transforms.Normalize((0.1307,), (0.3081,))
])),
batch_size=batch_size, shuffle=True)
class MLP(nn.Module):
def __init__(self):
super(MLP, self).__init__()
self.model = nn.Sequential( #定义网络的每一层,
nn.Linear(784, 200),
nn.ReLU(inplace=True),
nn.Linear(200, 200),
nn.ReLU(inplace=True),
nn.Linear(200, 10),
nn.ReLU(inplace=True),
)
def forward(self, x):
x = self.model(x)
return x
device = torch.device('cuda:0')
net = MLP().to(device)
#定义sgd优化器,指明优化参数、学习率,net.parameters()得到这个类所定义的网络的参数[[w1,b1,w2,b2,...]
optimizer = optim.SGD(net.parameters(), lr=learning_rate)
criteon = nn.CrossEntropyLoss().to(device)
for epoch in range(epochs):
for batch_idx, (data, target) in enumerate(train_loader):
data = data.view(-1, 28*28) #将二维的图片数据摊平[样本数,784]
data, target = data.to(device), target.cuda()
logits = net(data) #前向传播
loss = criteon(logits, target) #nn.CrossEntropyLoss()自带Softmax
optimizer.zero_grad() #梯度信息清空
loss.backward() #反向传播获取梯度
optimizer.step() #优化器更新
if batch_idx % 100 == 0: #每100个batch输出一次信息
print('Train Epoch: {} [{}/{} ({:.0f}%)]\tLoss: {:.6f}'.format(
epoch, batch_idx * len(data), len(train_loader.dataset),
100. * batch_idx / len(train_loader), loss.item()))
test_loss = 0
correct = 0 #correct记录正确分类的样本数
for data, target in test_loader:
data = data.view(-1, 28 * 28)
data, target = data.to(device), target.cuda()
logits = net(data)
test_loss += criteon(logits, target).item() #其实就是criteon(logits, target)的值,标量
pred = logits.data.max(dim=1)[1] #也可以写成pred=logits.argmax(dim=1)
correct += pred.eq(target.data).sum()
test_loss /= len(test_loader.dataset)
print('\nTest set: Average loss: {:.4f}, Accuracy: {}/{} ({:.0f}%)\n'.format(
test_loss, correct, len(test_loader.dataset),
100. * correct / len(test_loader.dataset)))
Train Epoch: 0 [0/60000 (0%)] Loss: 2.291108
Train Epoch: 0 [20000/60000 (33%)] Loss: 2.003711
Train Epoch: 0 [40000/60000 (67%)] Loss: 1.419139
Test set: Average loss: 0.0038, Accuracy: 8229/10000 (82%)
Train Epoch: 1 [0/60000 (0%)] Loss: 0.754257
Train Epoch: 1 [20000/60000 (33%)] Loss: 0.655030
Train Epoch: 1 [40000/60000 (67%)] Loss: 0.444529
Test set: Average loss: 0.0021, Accuracy: 8884/10000 (89%)
Train Epoch: 2 [0/60000 (0%)] Loss: 0.439030
Train Epoch: 2 [20000/60000 (33%)] Loss: 0.355868
Train Epoch: 2 [40000/60000 (67%)] Loss: 0.366360
Test set: Average loss: 0.0017, Accuracy: 9037/10000 (90%)
Train Epoch: 3 [0/60000 (0%)] Loss: 0.439010
Train Epoch: 3 [20000/60000 (33%)] Loss: 0.344060
Train Epoch: 3 [40000/60000 (67%)] Loss: 0.255032
Test set: Average loss: 0.0015, Accuracy: 9116/10000 (91%)
Train Epoch: 4 [0/60000 (0%)] Loss: 0.331074
Train Epoch: 4 [20000/60000 (33%)] Loss: 0.301065
Train Epoch: 4 [40000/60000 (67%)] Loss: 0.276514
Test set: Average loss: 0.0014, Accuracy: 9169/10000 (92%)
Train Epoch: 5 [0/60000 (0%)] Loss: 0.281249
Train Epoch: 5 [20000/60000 (33%)] Loss: 0.316320
Train Epoch: 5 [40000/60000 (67%)] Loss: 0.248902
Test set: Average loss: 0.0013, Accuracy: 9210/10000 (92%)
Train Epoch: 6 [0/60000 (0%)] Loss: 0.317820
Train Epoch: 6 [20000/60000 (33%)] Loss: 0.315888
Train Epoch: 6 [40000/60000 (67%)] Loss: 0.302683
Test set: Average loss: 0.0013, Accuracy: 9258/10000 (93%)
Train Epoch: 7 [0/60000 (0%)] Loss: 0.290187