Files
2024-12-11 13:29:29 +08:00

140 lines
3.8 KiB
Python

import matplotlib.pyplot as plt
import numpy as np
import torch
import torch.nn as nn
import torch.nn.functional as F
from torch.utils.data import DataLoader
from torchvision import datasets, transforms
# Super parameters
batch_size_small = 64
learning_rate = 0.01
momentum = 0.5
EPOCH = 10
# Prepare dataset
transform = transforms.Compose(
[transforms.ToTensor(), transforms.Normalize((0.1307,), (0.3081,))]
)
train_dataset = datasets.MNIST(
root="./data/mnist", train=True, download=True, transform=transform
)
test_dataset = datasets.MNIST(
root="./data/mnist", train=False, download=True, transform=transform
)
batch_size_full = len(train_dataset)
train_loader_small = DataLoader(
train_dataset, batch_size=batch_size_small, shuffle=True
)
train_loader_full = DataLoader(train_dataset, batch_size=batch_size_full, shuffle=True)
test_loader = DataLoader(test_dataset, batch_size=batch_size_small, shuffle=False)
class Net(torch.nn.Module):
def __init__(self):
super(Net, self).__init__()
self.fc1 = torch.nn.Linear(28 * 28, 512)
self.fc2 = torch.nn.Linear(512, 128)
self.fc3 = torch.nn.Linear(128, 10)
def forward(self, x):
x = x.view(-1, 28 * 28)
x = F.relu(self.fc1(x))
x = F.relu(self.fc2(x))
x = self.fc3(x)
return x
# Create two models
model_small_batch = Net()
model_full_batch = Net()
# Create optimizers
optimizer_small = torch.optim.SGD(
model_small_batch.parameters(), lr=learning_rate, momentum=momentum
)
optimizer_full = torch.optim.SGD(
model_full_batch.parameters(), lr=learning_rate, momentum=momentum
)
criterion = torch.nn.CrossEntropyLoss()
def train(epoch, model, optimizer, loader, name=""):
model.train()
running_loss = 0.0
running_total = 0
running_correct = 0
for batch_idx, (inputs, target) in enumerate(loader):
optimizer.zero_grad()
outputs = model(inputs)
loss = criterion(outputs, target)
loss.backward()
optimizer.step()
running_loss += loss.item()
_, predicted = torch.max(outputs.data, dim=1)
running_total += target.shape[0]
running_correct += (predicted == target).sum().item()
avg_loss = running_loss / len(loader)
avg_acc = 100 * running_correct / running_total
print(
f"[{epoch + 1} / {EPOCH}]: {name} Training Loss: {avg_loss:.3f}, Training Accuracy: {avg_acc:.2f} %"
)
def test(epoch, model, name=""):
model.eval()
correct = 0
total = 0
with torch.no_grad():
for data in test_loader:
images, labels = data
outputs = model(images)
_, predicted = torch.max(outputs.data, dim=1)
total += labels.size(0)
correct += (predicted == labels).sum().item()
acc = 100 * correct / total
print(
f"[{epoch + 1} / {EPOCH}]: {name} Accuracy on test set after epoch {epoch + 1}: {acc:.1f} %"
)
return acc
if __name__ == "__main__":
acc_list_small = []
acc_list_full = []
for epoch in range(EPOCH):
train(
epoch, model_small_batch, optimizer_small, train_loader_small, "Small Batch"
)
train(epoch, model_full_batch, optimizer_full, train_loader_full, "Full Batch")
acc_small = test(epoch, model_small_batch, "Small Batch")
acc_full = test(epoch, model_full_batch, "Full Batch")
acc_list_small.append(acc_small)
acc_list_full.append(acc_full)
plt.figure(figsize=(10, 6))
plt.plot(
range(1, EPOCH + 1),
acc_list_small,
label=f"Batch Size={batch_size_small}",
marker="o",
)
plt.plot(range(1, EPOCH + 1), acc_list_full, label="Full Batch", marker="s")
plt.xlabel("Epoch")
plt.ylabel("Accuracy On TestSet (%)")
plt.title("Comparison of Batch Sizes")
plt.legend()
plt.grid(True)
plt.show()