Files
2026-07-13 13:35:51 +08:00

158 lines
4.5 KiB
Python

import argparse
import torch
import torch.optim as optim
from model import Net
from torchvision import datasets, transforms
def train(args, model, device, train_loader, optimizer, epoch):
model.train()
for batch_idx, (data, target) in enumerate(train_loader):
data, target = data.to(device), target.to(device)
optimizer.zero_grad()
output = model(data)
loss = model.margin_loss(output, target)
loss.backward()
optimizer.step()
if batch_idx % args.log_interval == 0:
print(
"Train Epoch: {} [{}/{} ({:.0f}%)]\tLoss: {:.6f}".format(
epoch,
batch_idx * len(data),
len(train_loader.dataset),
100.0 * batch_idx / len(train_loader),
loss.item(),
)
)
def test(args, model, device, test_loader):
model.eval()
test_loss = 0
correct = 0
with torch.no_grad():
for data, target in test_loader:
data, target = data.to(device), target.to(device)
output = model(data)
test_loss += model.margin_loss(
output, target
).item() # sum up batch loss
pred = (
output.norm(dim=2).squeeze().max(1, keepdim=True)[1]
) # get the index of the max log-probability
correct += pred.eq(target.view_as(pred)).sum().item()
test_loss /= len(test_loader.dataset)
print(
"\nTest set: Average loss: {:.4f}, Accuracy: {}/{} ({:.0f}%)\n".format(
test_loss,
correct,
len(test_loader.dataset),
100.0 * correct / len(test_loader.dataset),
)
)
def main():
# Training settings
parser = argparse.ArgumentParser(description="PyTorch MNIST Example")
parser.add_argument(
"--batch-size",
type=int,
default=512,
metavar="N",
help="input batch size for training (default: 64)",
)
parser.add_argument(
"--test-batch-size",
type=int,
default=512,
metavar="N",
help="input batch size for testing (default: 1000)",
)
parser.add_argument(
"--epochs",
type=int,
default=10,
metavar="N",
help="number of epochs to train (default: 10)",
)
parser.add_argument(
"--lr",
type=float,
default=0.01,
metavar="LR",
help="learning rate (default: 0.01)",
)
parser.add_argument(
"--no-cuda",
action="store_true",
default=False,
help="disables CUDA training",
)
parser.add_argument(
"--seed",
type=int,
default=1,
metavar="S",
help="random seed (default: 1)",
)
parser.add_argument(
"--log-interval",
type=int,
default=10,
metavar="N",
help="how many batches to wait before logging training status",
)
args = parser.parse_args()
use_cuda = not args.no_cuda and torch.cuda.is_available()
torch.manual_seed(args.seed)
device = torch.device("cuda" if use_cuda else "cpu")
kwargs = {"num_workers": 1, "pin_memory": True} if use_cuda else {}
train_loader = torch.utils.data.DataLoader(
datasets.MNIST(
"../data",
train=True,
download=True,
transform=transforms.Compose(
[
transforms.ToTensor(),
transforms.Normalize((0.1307,), (0.3081,)),
]
),
),
batch_size=args.batch_size,
shuffle=True,
**kwargs
)
test_loader = torch.utils.data.DataLoader(
datasets.MNIST(
"../data",
train=False,
transform=transforms.Compose(
[
transforms.ToTensor(),
transforms.Normalize((0.1307,), (0.3081,)),
]
),
),
batch_size=args.test_batch_size,
shuffle=True,
**kwargs
)
model = Net(device=device).to(device)
optimizer = optim.Adam(model.parameters(), lr=args.lr)
for epoch in range(1, args.epochs + 1):
train(args, model, device, train_loader, optimizer, epoch)
test(args, model, device, test_loader)
if __name__ == "__main__":
main()