def test_basic(self):
"""
Basic test to check that the calculation is sensible.
"""
true_value1 = np.array([1, 2, 1, 2, 0, 0], dtype=np.int64)
pred_value1 = np.array([2, 1, 2, 1, 0, 0], dtype=np.int64)
self.assertAlmostEqual(
cluster_accuracy(true_value1, pred_value1)[1], 1.0)
self.assertAlmostEqual(
cluster_accuracy(true_value1, pred_value1, 3)[1], 1.0)
true_value2 = np.array([1, 1, 1, 1, 1, 1], dtype=np.int64)
pred_value2 = np.array([0, 1, 2, 3, 4, 5], dtype=np.int64)
self.assertAlmostEqual(
cluster_accuracy(true_value2, pred_value2)[1], 1.0 / 6.0)
self.assertAlmostEqual(
cluster_accuracy(true_value2, pred_value2, 6)[1], 1.0 / 6.0)
def main(cuda, batch_size, pretrain_epochs, finetune_epochs):
writer = SummaryWriter() # create the TensorBoard object
# callback function to call during training, uses writer from the scope
def training_callback(epoch, lr, loss, validation_loss):
writer.add_scalars('data/autoencoder', {
'lr': lr,
'loss': loss,
'validation_loss': validation_loss,
}, epoch)
ds_train = CachedMNIST(train=True, cuda=cuda) # training dataset
ds_val = CachedMNIST(train=False, cuda=cuda) # evaluation dataset
autoencoder = StackedDenoisingAutoEncoder([28 * 28, 500, 500, 2000, 10],
final_activation=None)
if cuda:
autoencoder.cuda()
print('Pretraining stage.')
ae.pretrain(
ds_train,
autoencoder,
cuda=cuda,
validation=ds_val,
epochs=pretrain_epochs,
batch_size=batch_size,
optimizer=lambda model: SGD(model.parameters(), lr=0.1, momentum=0.9),
scheduler=lambda x: StepLR(x, 100, gamma=0.1),
corruption=0.2)
print('Training stage.')
ae_optimizer = SGD(params=autoencoder.parameters(), lr=0.1, momentum=0.9)
ae.train(ds_train,
autoencoder,
cuda=cuda,
validation=ds_val,
epochs=finetune_epochs,
batch_size=batch_size,
optimizer=ae_optimizer,
scheduler=StepLR(ae_optimizer, 100, gamma=0.1),
corruption=0.2,
update_callback=training_callback)
print('k-Means stage')
dataloader = DataLoader(ds_train, batch_size=1024, shuffle=False)
kmeans = KMeans(n_clusters=10, n_init=20)
autoencoder.eval()
features = []
actual = []
for index, batch in enumerate(dataloader):
if (isinstance(batch, tuple)
or isinstance(batch, list)) and len(batch) == 2:
batch, value = batch # if we have a prediction label, separate it to actual
actual.append(value)
if cuda:
batch = batch.cuda(async=True)
batch = batch.squeeze(1).view(batch.size(0), -1)
features.append(autoencoder.encoder(batch).detach().cpu())
actual = torch.cat(actual).long().cpu().numpy()
predicted = kmeans.fit_predict(torch.cat(features).numpy())
reassignment, accuracy = cluster_accuracy(predicted, actual)
print('Final k-Means accuracy: %s' % accuracy)
predicted_reassigned = [reassignment[item]
for item in predicted] # TODO numpify
confusion = confusion_matrix(actual, predicted_reassigned)
normalised_confusion = confusion.astype('float') / confusion.sum(
axis=1)[:, np.newaxis]
confusion_id = uuid.uuid4().hex
sns.heatmap(normalised_confusion).get_figure().savefig('confusion_%s.png' %
confusion_id)
print('Writing out confusion diagram with UUID: %s' % confusion_id)
writer.add_embedding(
torch.cat(features),
metadata=predicted,
label_img=ds_train.ds.train_data.float().unsqueeze(1), # TODO bit ugly
tag='predicted')
writer.close()