03. logistic-regression


In [1]:
import torch
import torch.nn as nn
import torchvision.datasets as dsets
import torchvision.transforms as transforms
from torch.autograd import Variable

In [2]:
input_size = 784
num_classes = 10
num_epochs = 5
batch_size = 100
learning_rate = 0.001

In [4]:
train_dataset = dsets.MNIST(root='./data', 
                            train=True, 
                            transform=transforms.ToTensor(),
                            download=True)

test_dataset = dsets.MNIST(root='./data', 
                           train=False, 
                           transform=transforms.ToTensor())


Downloading http://yann.lecun.com/exdb/mnist/train-images-idx3-ubyte.gz
Downloading http://yann.lecun.com/exdb/mnist/train-labels-idx1-ubyte.gz
Downloading http://yann.lecun.com/exdb/mnist/t10k-images-idx3-ubyte.gz
Downloading http://yann.lecun.com/exdb/mnist/t10k-labels-idx1-ubyte.gz
Processing...
Done!

In [7]:
train_loader = torch.utils.data.DataLoader(dataset=train_dataset,
                                           batch_size=batch_size,
                                           shuffle=True)

In [6]:
test_loader = torch.utils.data.DataLoader(dataset=test_dataset,
                                          batch_size=batch_size,
                                          shuffle=False)

In [8]:
class LogisticRegression(nn.Module):
    def __init__(self, input_size, num_classes):
        super(LogisticRegression, self).__init__()
        self.linear = nn.Linear(input_size, num_classes)
        
    def forward(self, x):
        out = self.linear(x)
        return out

In [9]:
model = LogisticRegression(input_size, num_classes)

In [10]:
criterion = nn.CrossEntropyLoss()
optimizer = torch.optim.SGD(model.parameters(), lr=learning_rate)

In [17]:
for epoch in range(num_epochs):
    for i, (images, labels) in enumerate(train_loader):
        images = Variable(images.view(-1, 28*28))
        labels = Variable(labels)
        
        optimizer.zero_grad()
        outputs = model(images)
        loss = criterion(outputs, labels)
        loss.backward()
        optimizer.step()
        
        if (i+1) % 100 == 0:
            print("Epoch: [{}/{}], Step:[{}/{}], Loss: {:.4f}".format(
            epoch+1, num_epochs, i+1, len(train_dataset)//batch_size, loss.data[0]))


Epoch: [1/5], Step:[100/600], Loss: 0.9178
Epoch: [1/5], Step:[200/600], Loss: 0.8490
Epoch: [1/5], Step:[300/600], Loss: 1.0128
Epoch: [1/5], Step:[400/600], Loss: 0.9173
Epoch: [1/5], Step:[500/600], Loss: 0.8664
Epoch: [1/5], Step:[600/600], Loss: 0.8254
Epoch: [2/5], Step:[100/600], Loss: 0.8765
Epoch: [2/5], Step:[200/600], Loss: 0.7709
Epoch: [2/5], Step:[300/600], Loss: 0.9264
Epoch: [2/5], Step:[400/600], Loss: 0.9131
Epoch: [2/5], Step:[500/600], Loss: 0.8726
Epoch: [2/5], Step:[600/600], Loss: 0.8104
Epoch: [3/5], Step:[100/600], Loss: 0.8185
Epoch: [3/5], Step:[200/600], Loss: 0.8911
Epoch: [3/5], Step:[300/600], Loss: 0.7579
Epoch: [3/5], Step:[400/600], Loss: 0.7466
Epoch: [3/5], Step:[500/600], Loss: 0.8131
Epoch: [3/5], Step:[600/600], Loss: 0.6825
Epoch: [4/5], Step:[100/600], Loss: 0.7759
Epoch: [4/5], Step:[200/600], Loss: 0.7875
Epoch: [4/5], Step:[300/600], Loss: 0.7481
Epoch: [4/5], Step:[400/600], Loss: 0.6982
Epoch: [4/5], Step:[500/600], Loss: 0.8336
Epoch: [4/5], Step:[600/600], Loss: 0.7096
Epoch: [5/5], Step:[100/600], Loss: 0.5979
Epoch: [5/5], Step:[200/600], Loss: 0.7986
Epoch: [5/5], Step:[300/600], Loss: 0.7689
Epoch: [5/5], Step:[400/600], Loss: 0.7219
Epoch: [5/5], Step:[500/600], Loss: 0.6770
Epoch: [5/5], Step:[600/600], Loss: 0.6228

In [19]:
loss.data[0]


Out[19]:
0.6228074431419373

In [22]:
test_loader


Out[22]:
<torch.utils.data.dataloader.DataLoader at 0x10e23cda0>

In [23]:
correct = 0
total = 0
for images, labels in test_loader:
    images = Variable(images.view(-1, 28*28))
    outputs = model(images)
    _, predicted = torch.max(outputs.data, 1)
    total += labels.size(0)
    correct += (predicted == labels).sum()

In [25]:
print("Accuracy of model on the 10000 test images:{}%".format(100*correct/total))


Accuracy of model on the 10000 test images:85.87%

In [26]:
torch.save(model.state_dict(), 'linear_regression_model.pkl')

In [ ]: