Files
Machine-Learning-Collection/ML/Pytorch/pytorch_lightning/1. start code/simple_fc.py

111 lines
3.2 KiB
Python

import torch
import torch.nn.functional as F
import torchvision.datasets as datasets
import torchvision.transforms as transforms
from torch import nn, optim
from torch.utils.data import DataLoader
from tqdm import tqdm
from torch.utils.data import random_split
class NN(nn.Module):
def __init__(self, input_size, num_classes):
super().__init__()
self.fc1 = nn.Linear(input_size, 50)
self.fc2 = nn.Linear(50, num_classes)
def forward(self, x):
x = F.relu(self.fc1(x))
x = self.fc2(x)
return x
# Set device cuda for GPU if it's available otherwise run on the CPU
device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
# Hyperparameters
input_size = 784
num_classes = 10
learning_rate = 0.001
batch_size = 64
num_epochs = 3
# Load Data
entire_dataset = datasets.MNIST(
root="dataset/", train=True, transform=transforms.ToTensor(), download=True
)
train_ds, val_ds = random_split(entire_dataset, [50000, 10000])
test_ds = datasets.MNIST(
root="dataset/", train=False, transform=transforms.ToTensor(), download=True
)
train_loader = DataLoader(dataset=train_ds, batch_size=batch_size, shuffle=True)
val_loader = DataLoader(dataset=train_ds, batch_size=batch_size, shuffle=True)
test_loader = DataLoader(dataset=test_ds, batch_size=batch_size, shuffle=False)
# Initialize network
model = NN(input_size=input_size, num_classes=num_classes).to(device)
# Loss and optimizer
criterion = nn.CrossEntropyLoss()
optimizer = optim.Adam(model.parameters(), lr=learning_rate)
# Train Network
for epoch in range(num_epochs):
for batch_idx, (data, targets) in enumerate(tqdm(train_loader)):
# Get data to cuda if possible
data = data.to(device=device)
targets = targets.to(device=device)
# Get to correct shape
data = data.reshape(data.shape[0], -1)
# Forward
scores = model(data)
loss = criterion(scores, targets)
# Backward
optimizer.zero_grad()
loss.backward()
# Gradient descent or adam step
optimizer.step()
# Check accuracy on training & test to see how good our model
def check_accuracy(loader, model):
num_correct = 0
num_samples = 0
model.eval()
# We don't need to keep track of gradients here so we wrap it in torch.no_grad()
with torch.no_grad():
# Loop through the data
for x, y in loader:
# Move data to device
x = x.to(device=device)
y = y.to(device=device)
# Get to correct shape
x = x.reshape(x.shape[0], -1)
# Forward pass
scores = model(x)
_, predictions = scores.max(1)
# Check how many we got correct
num_correct += (predictions == y).sum()
# Keep track of number of samples
num_samples += predictions.size(0)
model.train()
return num_correct / num_samples
# Check accuracy on training & test to see how good our model
model.to(device)
print(f"Accuracy on training set: {check_accuracy(train_loader, model)*100:.2f}")
print(f"Accuracy on validation set: {check_accuracy(val_loader, model)*100:.2f}")
print(f"Accuracy on test set: {check_accuracy(test_loader, model)*100:.2f}")