İmageRecognition_usingPytorch_with_FashionMNIST_DataSet.py

# importing required libraries.. import torch import numpy as np import torch.nn as nn import torch.optim as optim import matplotlib.pyplot as plt from torchvision import datasets, transforms from torch.utils.data.sampler import SubsetRandomSampler # for validation test from Classifier import Classifier # Define a transform to convert to images to tensor and normalize transform = transforms.Compose( [ transforms.ToTensor(), transforms.Normalize( (0.5,), (0.5,), ), ] ) # mean and std have to be sequences (e.g., tuples), # therefore we should add a comma after the values # Load the data: train and test sets trainset = datasets.FashionMNIST( "~/.pytorch/F_MNIST_data", download=True, train=True, transform=transform ) testset = datasets.FashionMNIST( "~/.pytorch/F_MNIST_data", download=True, train=False, transform=transform ) # Preparing for validaion test indices = list(range(len(trainset))) np.random.shuffle(indices) # to get 20% of the train set split = int(np.floor(0.2 * len(trainset))) train_sample = SubsetRandomSampler(indices[:split]) valid_sample = SubsetRandomSampler(indices[split:]) # Data Loader trainloader = torch.utils.data.DataLoader(trainset, sampler=train_sample, batch_size=64) validloader = torch.utils.data.DataLoader(trainset, sampler=valid_sample, batch_size=64) testloader = torch.utils.data.DataLoader(testset, batch_size=64, shuffle=True) dataiter = iter(trainloader) print(len(dataiter)) # images, labels = dataiter.next() images, labels = dataiter.__next__() fig = plt.figure(figsize=(15, 5)) for idx in np.arange(20): # xticks=[], yticks=[] is empty to print the images without any ticks around them # np.sqeeze : Remove single-dimensional entries from the shape of an array. ax = fig.add_subplot(4, 5, idx + 1, xticks=[], yticks=[]) ax.imshow(np.squeeze(images[idx]), cmap="gray") # .item() gets the value contained in a Tensor ax.set_title(labels[idx].item()) fig.tight_layout() model = Classifier() # defining the loss function criterion = nn.NLLLoss() optimizer = optim.SGD(model.parameters(), lr=0.01) valid_loss_min = ( np.Inf ) # using this high value to make sure the update the weight first time epochs = 40 steps = 0 model.train() # prep model for training train_losses, valid_losses = [], [] for e in range(epochs): running_loss = 0 valid_loss = 0 # train the model # for images, labels in trainloader: optimizer.zero_grad() log_ps = model(images) loss = criterion(log_ps, labels) loss.backward() optimizer.step() running_loss += loss.item() * images.size(0) for images, labels in validloader: log_ps = model(images) loss = criterion(log_ps, labels) valid_loss += loss.item() * images.size(0) running_loss = running_loss / len(trainloader.sampler) valid_loss = valid_loss / len(validloader.sampler) train_losses.append(running_loss) valid_losses.append(valid_loss) print( "Epoch: {} \tTraining Loss: {:.6f} \tValidation Loss: {:.6f}".format( e + 1, running_loss, valid_loss ) ) if valid_loss <= valid_loss_min: print( "validation loss decreased({:.6f} -->{:.6f}). Saving Model ...".format( valid_loss_min, valid_loss ) ) torch.save(model.state_dict(), "model.pt") valid_loss_min = valid_loss plt.plot(train_losses, label="Train Loss") plt.plot(valid_losses, label="Valid Loss") plt.legend("Train Loss/Valid Loss") plt.show() model.load_state_dict(torch.load("model.pt")) # track the test loss test_loss = 0 class_correct = list(0.0 for i in range(10)) class_total = list(0.0 for i in range(10)) model.eval() for images, labels in testloader: # forword pass output = model(images) # calculate the loss loss = criterion(output, labels) # update the test loss test_loss += loss.item() * images.size(0) # convert output probabilities to predicted class _, pred = torch.max(output, 1) # compare predictions to the true labes correct = np.squeeze(pred.eq(labels.data.view_as(pred))) # calculate test accuracy for each object class for i in range(len(labels)): label = labels.data[i] class_correct[label] += correct[i].item() class_total[label] += 1 # calculate and prınt test loss test_loss = test_loss / len(testloader.sampler) print("Test Loss: {:.6f}\n".format(test_loss)) for i in range(10): if class_total[i] > 0: print( "Test Accuracy of %5s: %2d%% (%2d/%2d)" % ( str(i), 100 * class_correct[i] / class_total[i], np.sum(class_correct[i]), np.sum(class_total[i]), ) ) else: print("Test Accuracy of %5s: N/A(no training examples)" % class_total[i]) print( "\nTest Accuracy (Overall): %2d%% (%2d/%2d)" % ( 100.0 * np.sum(class_correct) / np.sum(class_total), np.sum(class_correct), np.sum(class_total), ) ) # obtain one batch of test images dataiter = iter(testloader) images, labels = dataiter.__next__() # get sample outputs output = model(images) # convert output probabilities to predicted class _, preds = torch.max(output, 1) # prep images for display images = images.numpy() # plot the images in the batch, along with predicted and true labels fig = plt.figure(figsize=(25, 4)) for idx in np.arange(20): ax = fig.add_subplot(2, 10, idx + 1, xticks=[], yticks=[]) ax.imshow(np.squeeze(images[idx]), cmap="gray") ax.set_title( "{} ({})".format(str(preds[idx].item()), str(labels[idx].item())), color=("green" if preds[idx] == labels[idx] else "red"), ) plt.show() print("Done!. There is a trained model named model.pt in this folder.")