def main(x_data, y_data, num_iterations, model, is_logit=True):
if is_logit:
optim = torch.optim.SGD(model.parameters(),
lr=0.01) # 70%=0.01) # 50%=0.001)
criterion = torch.nn.CrossEntropyLoss() # computes softmax internallyΩ
else:
optim = torch.optim.Adam(model.parameters(), lr=0.01)
# criterion = torch.nn.NLLLoss() # size_average=True
# criterion = torch.nn.MSELoss(reduction='sum')
for j in range(num_iterations):
# run the model forward on the data
if is_logit:
y_pred = model(x_data).squeeze(-1)
# calculate the log loss, when forward computes regression
loss = criterion(y_pred, y_data) # (outputs, labels)
else:
y_pred = model(x_data)
# loss = criterion(input=y_pred, target=y_data)
loss = nn.functional.binary_cross_entropy(input=y_pred.squeeze(-1),
target=y_data)
# initialize gradients to zero
optim.zero_grad()
# backpropagate
loss.backward()
# take a gradient step
optim.step()
if (j + 1) % 50 == 0:
print("\n [iteration %04d] loss: %.4f " % (j + 1, loss.item()))
if is_logit:
outputs = model(x_data)
_, predicted = torch.max(outputs.data, 1)
correct = (predicted == y_data).sum()
print('Accuracy of logistic model: {} %'.format(
100 * correct / y_data.size(0)))
else:
y_pred = model(x_data).squeeze(-1)
error_mean = ((y_pred > 0.5).float() -
y_data_float).abs().mean()
print('Accuracy of regression model: {} %'.format(100. - 100. *
error_mean))
# Inspect learned parameters
print("Learned parameters:")
for name, param in model.named_parameters():
print(name, param.data.numpy())
def main():
x_data = data[:, :-1]
y_data = data[:, -1]
for j in range(num_iterations):
# run the model forward on the data
y_pred = net(x_data).squeeze(-1)
# calculate the mse loss
loss = loss_fn(y_pred, y_data)
# initialize gradients to zero
optim.zero_grad()
# backpropagate
loss.backward()
# take a gradient step
optim.step()
if (j + 1) % 50 == 0:
print("[iteration %04d] loss: %.4f" % (j + 1, loss.item()))
# Inspect learned parameters
print("Learned parameters:")
for name, param in net.named_parameters():
print(name, param.data.numpy())
def main():
# x_data = train
# y_data = test
X, y = train[:, 0:n_lag], train[:, n_lag:]
X = X.reshape(X.shape[0], 1, X.shape[1])
x_data, y_data = np.array(X), np.array(y)
x_data = torch.tensor(x_data, dtype=torch.float)
y_data = torch.tensor(y_data, dtype=torch.float)
print(x_data.shape)
print(y_data.shape)
for j in range(num_iterations):
y_pred = regression_model(x_data).squeeze(-1)
loss = loss_fn(y_pred, y_data)
optim.zero_grad()
loss.backward()
optim.step()
if (j + 1) % 100 == 0:
print("[iteration %04d] loss: %.4f" % (j + 1, loss.item()))
print("Learned parameters:")
for name, param in regression_model.named_parameters():
print(name, param.data.numpy())