def n_layer_nn(optimiser_function, layer_dims=[28*28 + 1, 128, 10], learning_rate=0.1, epochs=100):
layers = len(layer_dims)
assert layers >= 3, "Please give at leaset 3 dimensions"
modules = [Linear(layer_dims[0], layer_dims[1]), Relu()]
for i in range(1, layers - 2):
modules.append(Linear(layer_dims[i], layer_dims[i+1]))
modules.append(Relu())
modules.append(Linear(layer_dims[layers-2], layer_dims[layers-1]))
modules.append(Sigmoid())
print(modules)
model = Sequential(*modules).cuda('cuda:0')
loss_function = CrossEntropyLoss()
optimiser = optimiser_function(model.parameters(), lr=learning_rate)
stopper = EarlyStop(patience=3)
train_losses=[]
val_losses=[]
accuracy=[]
for epoch in range(epochs):
losses=[]
for i,(X, y) in enumerate(get_minibatches(train_loader, device)):
optimiser.zero_grad()
yhat = model.forward(X)
loss = loss_function(yhat, y.argmax(1))
losses.append(loss.item())
loss.backward()
optimiser.step()
train_losses.append(np.mean(losses))
if epoch % 3 == 0:
with torch.no_grad():
losses = []
corrects = 0
for i,(X, y) in enumerate(get_minibatches(val_loader, device)):
y = y.argmax(1)
yhat = model.forward(X)
losses.append(loss_function(yhat, y).item())
ypred = yhat.argmax(1)
corrects += (ypred == y).sum()
val_loss = np.mean(losses)
val_losses.append(val_loss)
acc = corrects.cpu().numpy() / val_size
#print("Accuracy {}".format(acc))
accuracy.append(acc)
if not stopper.continue_still(val_loss):
print("Early stop at epoch {}".format(epoch))
break
return val_losses, accuracy
Sigmoid()
).cuda('cuda:0')
loss_function = CrossEntropyLoss()
optimiser = SGD(model.parameters(), lr=0.02)
train_loss=[]
val_loss=[]
accuracy=[]
for epoch in range(100):
losses=[]
for i,(X, y) in enumerate(get_minibatches(train_loader, device)):
optimiser.zero_grad()
yhat = model.forward(X)
loss = loss_function(yhat, y.argmax(1))
losses.append(loss.item())
loss.backward()
optimiser.step()
train_loss.append(np.mean(losses))
if epoch % 10 == 0:
with torch.no_grad():
losses = []
corrects = 0
for i,(X, y) in enumerate(get_minibatches(val_loader, device)):
y = y.argmax(1)
yhat = model.forward(X)
losses.append(loss_function(yhat, y).item())