Sorry, for bothering you again.
I am trying to train a resnet18 model to classify images into three different classes. Therefore, I wrote a class train_one_epoch. I would like to calculate the accuracy of the training during one epoch, so I wrote a class accuracy, too. I know, that this kind of accuracy class only siuts binary classifications. The images I feed the netowrk with are in RGB and 350x350. However, I was wondering, why the size of my outputs is [8, 1000] after passing the images to the network. Shouldn’t it be [8, 3]. Afterwards I could
use the maximum as predicted class or am I missing something essential?
Any help is appreciated.
# device configuration, use cuda if possible
device = torch.device('cuda' if torch.cuda.is_available() else 'cpu')
# define hyper-parameters
num_epochs = 10
learning_rate = 0.001
batchsize = 8
resnet18 = models.resnet18()
resnet18.fc.out_features = 3
# print(resnet18)
resnet18.to(device)
...
def accuracy(outputs, trues):
### Converting preds to 0 or 1
outputs = [1 if outputs[i] >= 0.5 else 0 for i in range(len(outputs))]
print(outputs)
### Calculating accuracy by comparing predictions with true labels
acc = [1 if outputs[i] == trues[i] else 0 for i in range(len(outputs))]
### Summing over all correct predictions
acc = np.sum(acc) / len(outputs)
return (acc * 100)
# train the model with the help of a for-loop
total_step = len(train_data_loader)
curr_lr = learning_rate
def train_one_epoch(train_data_loader):
epoch_loss = []
epoch_acc = []
start_time = time.time()
for images, labels in train_data_loader:
images = images.to(device)
labels = labels.to(device)
# forward pass
optimizer.zero_grad()
outputs = resnet18(images)
print(outputs.size())
print(labels.size())
# calculating accuracy and loss
_loss = criterion(outputs, labels)
loss = _loss.item()
epoch_loss.append(loss)
acc = accuracy(outputs, labels)
epoch_acc.append(acc)
# backward and optimize
_loss.backward()
optimizer.step()
end_time = time.time()
total_time = end_time - start_time
###Acc and Loss
epoch_loss = np.mean(epoch_loss)
epoch_acc = np.mean(epoch_acc)
###Storing results to logs
train_logs["loss"].append(epoch_loss)
train_logs["accuracy"].append(epoch_acc)
train_logs["time"].append(total_time)
return epoch_loss, epoch_acc, total_time
