146 lines
3.3 KiB
Python
146 lines
3.3 KiB
Python
import torch
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from torch import nn
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from torch.utils.data import DataLoader
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from torchvision import datasets
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from torchvision.transforms import ToTensor
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training_data = datasets.FashionMNIST(
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root="data",
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train=True,
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download=True,
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transform=ToTensor(),
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)
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test_data = datasets.FashionMNIST(
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root="data",
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train=False,
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download=True,
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transform=ToTensor(),
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)
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print(training_data)
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print(test_data)
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batch_size=8192
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train_dataloader = DataLoader(training_data, batch_size=batch_size, shuffle=True)
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test_dataloader = DataLoader(test_data, batch_size=batch_size, shuffle=True)
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for X, y in test_dataloader:
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print(f"Shape of X [N, C, H, W]: {X.shape}")
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print(f"Shape of y: {y.shape} {y.dtype}")
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break
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device = (
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"cuda" if torch.cuda.is_available()
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else "mps" if torch.backends.mps.is_available()
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else "cpu"
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)
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print(device)
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class NeuralNetwork(nn.Module):
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def __init__(self):
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super().__init__()
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self.flatten = nn.Flatten()
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self.linear_relu_stack = nn.Sequential(
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nn.Linear(28 * 28, 512),
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nn.BatchNorm1d(512),
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nn.ReLU(),
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nn.Linear(512, 512),
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nn.BatchNorm1d(512),
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nn.ReLU(),
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nn.Linear(512, 512),
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nn.BatchNorm1d(512),
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nn.ReLU(),
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nn.Linear(512, 512),
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nn.BatchNorm1d(512),
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nn.ReLU(),
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nn.Linear(512, 512),
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nn.BatchNorm1d(512),
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nn.ReLU(),
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nn.Linear(512, 10)
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)
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def forward(self, x):
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# torch.Size([64, 1, 28, 28])
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# torch.Size([64, 784])
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# torch.Size([64, 10])
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# print("=====")
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#print(x.shape)
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x = self.flatten(x)
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#print(x.shape)
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logits = self.linear_relu_stack(x)
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#print(logits.shape)
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return logits
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model = NeuralNetwork().to(device)
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print(model)
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loss_fn = nn.CrossEntropyLoss().to(device)
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optimizer = torch.optim.AdamW(model.parameters(), lr=1e-3)
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def train(dataloader, model, loss_fn, optimizer):
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size = len(dataloader.dataset)
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model.train()
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for batch, (X, y) in enumerate(dataloader):
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X, y = X.to(device), y.to(device)
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pred = model(X)
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loss = loss_fn(pred, y)
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optimizer.zero_grad()
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loss.backward()
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optimizer.step()
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if batch % 100 == 0:
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loss, current = loss.item(), (batch + 1) * len(X)
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print(f"loss: {loss:>7f} [{current:>5d}/{size:>5d}]")
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def test(dataloader, model, loss_fn):
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size = len(dataloader.dataset)
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num_batches = len(dataloader)
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model.eval()
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test_loss, correct = 0, 0
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with torch.no_grad():
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for X, y in dataloader:
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X, y = X.to(device), y.to(device)
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pred = model(X)
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test_loss += loss_fn(pred, y).item()
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correct += (pred.argmax(1) == y).type(torch.float).sum().item()
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test_loss /= num_batches
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correct /= size
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print(f"Test Error: \n Accuracy: {(100*correct):>0.1f}%, Avg loss: {test_loss:>8f} \n")
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epochs = 5
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for t in range(epochs):
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print(f"Epoch {t+1}\n---------------------")
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train(train_dataloader, model, loss_fn, optimizer)
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test(test_dataloader, model, loss_fn)
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print("Done!")
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torch.save(model.state_dict(), "model.pth")
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print("Saved PyTorch Model Sate to model.pth")
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model = NeuralNetwork()
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model.load_state_dict(torch.load("model.pth"))
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classes = [
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"T-shirt/top",
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"Trouser",
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"Pullover",
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"Dress",
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"Coat",
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"Sandal",
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"Shirt",
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"Sneaker",
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"Bag",
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"Ankle Boot",
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]
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model.eval()
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x, y = test_data[0][0], test_data[0][1]
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with torch.no_grad():
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pred = model(x)
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predicted, actual = classes[pred[0].argmax(0)], classes[y]
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print(f'Predicted: "{predicted}", Actual: "{actual}"')
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