def train():
"""
Performs training and evaluation of ConvNet model.
TODO:
Implement training and evaluation of ConvNet model. Evaluate your model on
the whole test set each eval_freq iterations.
"""
### DO NOT CHANGE SEEDS!
# Set the random seeds for reproducibility
np.random.seed(42)
torch.manual_seed(42)
#all external parameters in a readable format.
lr = FLAGS.learning_rate
max_steps = FLAGS.max_steps
batch_size = FLAGS.batch_size
eval_freq = FLAGS.eval_freq
data_dir = FLAGS.data_dir
#fetch data
data = cifar10_utils.get_cifar10(data_dir)
n_classes = 10
n_channels = 3
#number of iterations to train the data in the whole dataset:
n_iter = 1 # int(np.ceil(data["train"]._num_examples/batch_size))
#number of evaluations
num_evals = int(np.ceil(data['test']._num_examples / batch_size))
#load model
cnn_model = ConvNet(n_channels, n_classes)
#Loss function
loss_XE = torch.nn.CrossEntropyLoss()
#keep track of how loss and accuracy evolves over time.
loss_train = np.zeros(max_steps + 1) #loss on training data
acc_train = np.zeros(max_steps + 1) #accuracy on training data
loss_eval = np.zeros(max_steps + 1) #loss on test data
acc_eval = np.zeros(max_steps + 1) #accuracy on test data
#Optimizer
optmizer = optim.Adam(cnn_model.parameters(), lr=lr)
#let's put some gpus to work!
cnn_model.to(device)
#index to keep track of the evaluations.
eval_i = 0
#Train shit
for s in range(max_steps):
for n in range(n_iter):
#fetch next batch of data
X, y = data['train'].next_batch(batch_size)
#use torch tensor + gpu
X = torch.from_numpy(X).type(dtype).to(device)
y = torch.from_numpy(y).type(dtype).to(device)
#reset gradient to zero before gradient descent.
optmizer.zero_grad()
#calculate loss
probs = cnn_model(X) #automatically calls .forward()
loss = loss_XE(probs, y.argmax(dim=1))
#backward propagation
loss.backward()
optmizer.step()
#stores the loss and accuracy of the trainind data for later analysis.
loss_train[eval_i] += loss.item() / num_evals #
acc_train[eval_i] += accuracy(probs, y) / num_evals
probs.detach()
if (s % eval_freq == 0) | (s == (max_steps - 1)):
#calculate accuracy for the whole data set
for t in range(num_evals):
#fetch all the data
X, y = data['test'].next_batch(batch_size)
#use torch tensor + gpu, no gradient needed.
X = torch.tensor(X, requires_grad=False).type(dtype).to(device)
y = torch.tensor(y, requires_grad=False).type(dtype).to(device)
#actually calculates loss and accuracy for the batch
probs = cnn_model.forward(X)
loss_eval[eval_i] += loss_XE(
probs,
y.argmax(dim=1)).item() # detach().data.cpu().item()
acc_eval[eval_i] += accuracy(probs, y)
probs.detach()
#frees memory
X.detach()
y.detach()
#average the losses and accuracies across test batches
loss_eval[eval_i] /= num_evals
acc_eval[eval_i] /= num_evals
#print performance
print(f"step {s} out of {max_steps}")
print(
f" loss: {loss_eval[eval_i]}, accuracy: {acc_eval[eval_i]}")
print(
f" loss: {loss_train[eval_i]}, accuracy: {acc_train[eval_i]}"
)
#save the results
# np.save("loss_eval", loss_eval)
# np.save("accuracy_eval", acc_eval)
#increments eval counter
eval_i += 1
#Save intermediary results for later analysis
print("saving results in folder...")
np.save("loss_train", loss_train)
np.save("accuracy_train", acc_train)
np.save("loss_eval", loss_eval)
np.save("accuracy_eval", acc_eval)
print("savign model")
torch.save(cnn_model.state_dict(), cnn_model.__class__.__name__ + ".pt")
def train():
"""
Performs training and evaluation of ConvNet model.
"""
### DO NOT CHANGE SEEDS!
# Set the random seeds for reproducibility
np.random.seed(42)
torch.manual_seed(42)
########################
lr = FLAGS.learning_rate
max_steps = FLAGS.max_steps
batch_size = FLAGS.batch_size
eval_freq = FLAGS.eval_freq
data_dir = FLAGS.data_dir
optim = FLAGS.optimizer
#fetch data
cifar10 = cifar10_utils.get_cifar10(data_dir)
n_classes = 10
n_channels = 3
eval_rounds = int(np.ceil(cifar10['test']._num_examples / batch_size))
model = ConvNet(n_channels, n_classes)
ce = torch.nn.CrossEntropyLoss()
pars = model.parameters()
# optimizer
optim_pars = {'params': pars, 'lr': lr, 'weight_decay': FLAGS.weight_decay}
if optim == 'adadelta':
optimizer = torch.optim.Adadelta(**optim_pars)
elif optim == 'adagrad':
optimizer = torch.optim.Adagrad(**optim_pars)
elif optim == 'rmsprop':
optimizer = torch.optim.RMSprop(**optim_pars)
elif optim == 'adam':
optimizer = torch.optim.Adam(**optim_pars)
else: # SGD
optimizer = torch.optim.SGD(**optim_pars)
model.to(device)
eval_i = 0
cols = ['train_acc', 'test_acc', 'train_loss', 'test_loss', 'secs']
# train
results = []
name = f'convnet-pytorch-{optim}'
with SummaryWriter(name) as w:
for step in tqdm(range(FLAGS.max_steps)):
optimizer.zero_grad()
X, y = cifar10['train'].next_batch(batch_size)
X = torch.tensor(X).type(dtype).to(device)
train_predictions = model.forward(X)
X.detach()
y = torch.tensor(y).type(dtype).to(device)
train_acc = accuracy(train_predictions, y)
idx_train = torch.argmax(y, dim=-1).long()
y.detach()
train_loss = ce(train_predictions, idx_train)
train_predictions.detach()
# stop if loss has converged!
check = 10
if len(results) >= 2 * check:
threshold = 1e-6
losses = [result['test_loss'] for result in results]
current = np.mean(losses[-check:])
prev = np.mean(losses[-2 * check:-check])
if (prev - current) < threshold:
break
# # at each epoch, we divide the learning rate by this if the dev accuracy decreases
# if dev_acc > prev_acc:
# lr /= learning_decay
# prev_acc = dev_acc
train_loss.backward()
optimizer.step()
# evaluate
if step % FLAGS.eval_freq == 0:
time = int(step / FLAGS.eval_freq)
start = timer()
test_accs = []
test_losses = []
for t in range(eval_rounds):
X, y = cifar10['test'].next_batch(batch_size)
X = torch.tensor(
X, requires_grad=False).type(dtype).to(device)
y = torch.tensor(
y, requires_grad=False).type(dtype).to(device)
test_predictions = model.forward(X)
X.detach()
test_accs.append(accuracy(test_predictions, y))
test_losses.append(
ce(test_predictions, y.argmax(dim=1)).item())
test_predictions.detach()
y.detach()
end = timer()
secs = end - start
test_acc = np.mean(test_accs)
test_loss = np.mean(test_losses)
vals = [train_acc, test_acc, train_loss, test_loss, secs]
stats = dict(
zip(cols, [
np.asscalar(i.detach().cpu().numpy().take(0))
if isinstance(i, torch.Tensor) else np.asscalar(i)
if isinstance(i, (np.ndarray, np.generic)) else i
for i in vals
]))
print(
yaml.dump({
k: round(i, 3) if isinstance(i, float) else i
for k, i in stats.items()
}))
w.add_scalars('metrics', stats, time)
results.append(stats)
df = pd.DataFrame(results, columns=cols)
meta = {
'framework': 'pytorch',
'algo': 'convnet',
'optimizer': optim,
'batch_size': FLAGS.batch_size,
'learning_rate': FLAGS.learning_rate,
'dnn_hidden_units': '',
'weight_decay': FLAGS.weight_decay,
'max_steps': FLAGS.max_steps,
}
for k, v in meta.items():
df[k] = v
output_file = 'results/results.csv' # f'{name}.csv'
if os.path.isfile(output_file):
df.to_csv(f'{name}.csv', header=False, mode='a')
else:
df.to_csv(f'{name}.csv', header=True, mode='w')
torch.save(model.state_dict(), f'{name}.pth')
print('done!')
return test_loss