def reg_logistic_implementation(y, x, degrees, ratio, seed, max_iters, gamma):
from helpers import build_poly, split_data
# Split the data based on the input ratio into training and testing data
x_tr, y_tr, x_te, y_te = split_data(x,y,ratio,seed)
losses_tr = []
losses_te = []
for degree in degrees:
print('degree = ',degree)
# Build a training polynomial basis based on the choice of degree
tx_tr = build_poly(x_tr, degree)
# Initialize starting point of the gradient descent
initial_w = np.zeros(tx_tr.shape[1])
# Perform iteration - calculate w(t+1) and calculate the new loss
w, loss_tr = reg_logistic_regression(y_tr, tx_tr, initial_w, max_iters, gamma)
np.append(losses_tr,loss_tr)
# Build a testing polynomial basis based on the choice of degree
tx_te = build_poly(x_te, degree)
# Test the validity of the predictions with the help of the test data
correct_percentage, loss_te = reg_logistic_test(y_te,tx_te,w,degree)
np.append(losses_te,loss_te)
return
def cross_validation_rr(y, x, k_indices, k, lambda_, degree):
"""train and test ridge regression model using cross validation"""
x_test = x[k_indices[k]]
x_train = np.delete(x, [k_indices[k]], axis=0)
y_test = y[k_indices[k]]
y_train = np.delete(y, [k_indices[k]], axis=0)
x_tr_poly = helpers.build_poly(x_train, degree)
x_te_poly = helpers.build_poly(x_test, degree)
w, loss_tr = imp.ridge_regression(y_train, x_tr_poly, lambda_)
loss_te = imp.compute_mse(y_test, x_te_poly, w)
return loss_tr, loss_te
def cross_validation_ridge_regression(y, x, k_indices, k, lambdas, degrees):
"""
Completes k-fold cross-validation using the ridge regression method.
Here, we build polynomial features and create four subsets using
the jet feature.
"""
# get k'th subgroup in test, others in train
msk_test = k_indices[k]
msk_train = np.delete(k_indices, (k), axis=0).ravel()
x_train_all_jets = x[msk_train, :]
x_test_all_jets = x[msk_test, :]
y_train_all_jets = y[msk_train]
y_test_all_jets = y[msk_test]
# split in 4 subsets the training set
msk_jets_train = get_jet_masks(x_train_all_jets)
msk_jets_test = get_jet_masks(x_test_all_jets)
# initialize output vectors
y_train_pred = np.zeros(len(y_train_all_jets))
y_test_pred = np.zeros(len(y_test_all_jets))
for idx in range(len(msk_jets_train)):
x_train = x_train_all_jets[msk_jets_train[idx]]
x_test = x_test_all_jets[msk_jets_test[idx]]
y_train = y_train_all_jets[msk_jets_train[idx]]
# data pre-processing
x_train, x_test = process_data(x_train, x_test, False)
phi_train = build_poly(x_train, degrees[idx])
phi_test = build_poly(x_test, degrees[idx])
phi_train = add_constant_column(phi_train)
phi_test = add_constant_column(phi_test)
# compute weights using given method
weights, loss = ridge_regression(y=y_train, tx=phi_train, lambda_=lambdas[idx])
y_train_pred[msk_jets_train[idx]] = predict_labels(weights, phi_train)
y_test_pred[msk_jets_test[idx]] = predict_labels(weights, phi_test)
# compute accuracy for train and test data
acc_train = compute_accuracy(y_train_pred, y_train_all_jets)
acc_test = compute_accuracy(y_test_pred, y_test_all_jets)
return acc_train, acc_test
def least_squares_demo(y, x, k):
"""return error for least square model"""
seed = 1
weights=[]
mse_errors = []
tx = helpers.build_poly(x, 1)
# Initialization
w_initial = np.zeros(tx.shape[1])
# split data in k fold
k_indices = helpers.build_k_indices(y, k, seed)
for i in range(k):
mse_te, opt_w = cross_validation_ls(y, tx, k_indices, i)
mse_errors.append(mse_te)
weights.append([opt_w])
mse = np.min(mse_errors)
opt_w = weights[np.argmin(mse_errors)]
y_model = helpers.predict_labels(np.array(opt_w).T, tx)
#Computing accuracy
print(" mse={mse}".format(mse = mse))
accuracy = (list(y_model.flatten() == y).count(True))/len(y_model)
print(" accuracy={acc:.3f}".format(acc=accuracy))
def cross_validation(y, x, k_indices, k, lambda_, degree):
te_indice = k_indices[k]
tr_indice = k_indices[~(np.arange(k_indices.shape[0]) == k)]
tr_indice = tr_indice.reshape(-1)
y_te, y_tr = y[te_indice], y[tr_indice]
x_te, x_tr = x[te_indice], x[tr_indice]
tx_tr = build_poly(x_tr, degree)
tx_te = build_poly(x_te, degree)
w, _ = ridge_regression(y_tr, tx_tr, lambda_)
y_tr_pred = predict_labels(w, tx_tr)
y_te_pred = predict_labels(w, tx_te)
loss_tr = sum(y_tr_pred != y_tr) / len(y_tr)
loss_te = sum(y_te_pred != y_te) / len(y_te)
return loss_tr, loss_te, w
def logistic_implementation(y,
x,
degrees,
ratio,
seed,
max_iters,
gamma,
Newton=False):
from helpers import build_poly, split_data
x_tr, y_tr, x_te, y_te = split_data(x, y, ratio, seed)
losses_tr = []
losses_te = []
for degree in degrees:
print('degree = ', degree)
tx_tr = build_poly(x_tr, degree)
initial_w = np.zeros(tx_tr.shape[1])
if Newton == False:
w, loss_tr = logistic_regression(y_tr, tx_tr, initial_w, max_iters,
gamma)
else:
w, loss_tr = logistic_newton(y_tr, tx_tr, initial_w, max_iters)
np.append(losses_tr, loss_tr)
tx_te = build_poly(x_te, degree)
correct_percentage, loss_te = logistic_test(y_te, tx_te, w, degree)
np.append(losses_te, loss_te)
#plt.plot(degrees,losses_tr,'r',degrees,losses_te,'b')
return
def lrr_demo(y, x, k):
"""find best hyperparameters and return error for regularized logistic regression model"""
#Adding constant term
tx = helpers.build_poly(x, 4)
seed = 1
max_iters = 50
lambdas = np.logspace(-4, -3, 1)
gammas = np.logspace(-4, -3, 1)
hyperparams = [(gamma,lambda_) for gamma in gammas for lambda_ in lambdas]
w_initial = np.zeros(tx.shape[1])
# split data in k fold
k_indices = helpers.build_k_indices(y, k, seed)
result_loss =[]
result_opt_w=[]
for gamma,lambda_ in hyperparams:
loss_errors=[]
weights=[]
for i in range(k):
loss_te, opt_w = cross_validation_lrr(y, tx, k_indices, i, lambda_, gamma, max_iters, w_initial)
loss_errors.append(loss_te)
weights.append([opt_w])
result_loss.append(np.mean(loss_errors))
result_opt_w.append(np.mean(weights,axis=0))
del loss_errors
del weights
mse = np.min(result_loss)
hyper_opt= hyperparams[np.argmin(result_loss)]
print(" gamma={g:.3f}, mse={mse:.3f} lambda{l:.3f}".format(mse = mse, g=hyper_opt[0], l=hyper_opt[1]))
opt_w = result_opt_w[np.argmin(result_loss)]
#Training Accuracy
y_predicted = helpers.predict_labels(opt_w.T, tx)
accuracy = (list(y_predicted.flatten() == y).count(True))/len(y)
print(" accuracy={acc:.3f}".format(acc=accuracy))
del result_loss
del result_opt_w
def lr_demo(y, x, k):
"""find best hyperparameters and return error for logistic regression model"""
max_iters = 100
gammas = np.logspace(-4, -3, 1)
seed = 1
# adding constant term
tx = helpers.build_poly(x, 1)
# Initialization
w_initial = np.zeros(tx.shape[1])
# split data in k fold
k_indices = helpers.build_k_indices(y, k, seed)
gen_opt_w = []
gen_loss = []
#gamma selection
for gamma in gammas:
weights=[]
loss_errors = []
for i in range(k):
loss_te, opt_w = cross_validation_lr(y, tx, k_indices, i, gamma, max_iters, w_initial)
loss_errors.append(loss_te)
weights.append([opt_w])
gen_loss.append(np.mean(loss_errors))
gen_opt_w.append(np.mean(weights,axis=0))
del weights
del loss_errors
opt_gamma = gammas[np.nanargmin(gen_loss)]
opt_w = gen_opt_w[np.nanargmin(gen_loss)]
print(" gamma={l:.3f},loss={loss:.3f}".format(loss = np.min(gen_loss), l = opt_gamma))
#Training Accuracy
y_predicted = helpers.predict_labels(opt_w.T, tx)
accuracy = (list(y_predicted.flatten() == y).count(True))/len(y)
print(" accuracy={acc:.3f}".format(acc = accuracy))
del gen_opt_w
del gen_loss
def LS_SGD_demo(y, x, k):
"""find best hyperparameters and return error for least square SGD model"""
#Adding constant term
tx = helpers.build_poly(x, 1)
seed = 1
max_iters = 50
gammas = np.logspace(-3, 0, 10)
batch_sizes = np.array([1])
# Initialization
w_initial = np.zeros(tx.shape[1])
# split data in k fold
k_indices = helpers.build_k_indices(y, k, seed)
temp_mse = []
temp_opt_w = []
hyperparams = [(batch_size,gamma) for batch_size in batch_sizes for gamma in gammas ]
for batch_size, gamma in hyperparams:
mse_errors = []
weights = []
for i in range(k):
mse_te, opt_w = cross_validation_ls_SGD(y, tx, k_indices, i, gamma, max_iters, w_initial, batch_size)
mse_errors.append(mse_te)
weights.append([opt_w])
temp_mse.append(np.mean(mse_errors))
temp_opt_w.append(np.mean(weights, axis=0))
mse = np.min(temp_mse)
hyper_opt= hyperparams[np.argmin(temp_mse)]
print(" gamma={g:.3f}, batch={b:.2f}, mse={mse:.3f}".format(mse = mse, g = hyper_opt[1], b = hyper_opt[0]))
opt_w = temp_opt_w[np.nanargmin(temp_mse)]
#Training Accuracy
y_predicted = helpers.predict_labels(opt_w.T, tx)
accuracy = (list(y == y_predicted.flatten()).count(True))/len(y)
print(" accuracy={acc:.3f}".format(acc = accuracy))
def LS_GD_demo(y, x, k):
"""find best hyperparameters and return error for least square GD model"""
seed=1
max_iters = 50
gammas = np.logspace(-3, 0, 10)
tx = helpers.build_poly(x, 1)
# Initialization
w_initial = np.zeros(tx.shape[1])
# split data in k fold
k_indices = helpers.build_k_indices(y, k, seed)
gen_opt_w = []
gen_mse = []
#gamma selection
for gamma in gammas:
weights=[]
mse_errors = []
for i in range(k):
mse_te, opt_w = cross_validation_ls_GD(y, tx, k_indices, i, gamma,max_iters, w_initial)
mse_errors.append(mse_te)
weights.append([opt_w])
gen_mse.append(np.mean(mse_errors))
gen_opt_w.append(np.mean(weights, axis=0))
del weights
del mse_errors
opt_gamma = gammas[np.nanargmin(gen_mse)]
opt_w = gen_opt_w[np.nanargmin(gen_mse)]
mse_LS_GD = np.nanmin(gen_mse)
print(" gamma={l:.3f}, mse={mse:.3f}".format(mse = mse_LS_GD, l = opt_gamma))
#Training Accuracy
y_predicted = helpers.predict_labels(opt_w.T, tx)
accuracy = (list(y == y_predicted.flatten()).count(True))/len(y)
print(" accuracy={acc:.3f}".format(acc=accuracy))
def ridge_regression_demo(y, x, degree, k_fold):
"""find best hyperparameters and return error for ridge regression model"""
seed = 1
lambdas = np.logspace(-1.1, -0.8, 20)
# split data in k fold
k_indices = helpers.build_k_indices(y, k_fold, seed)
# define lists to store the loss of training data and test data
rmse_tr = []
rmse_te = []
# iterate over all the lambdas, compute model parameters, store the rmse
for i in range(len(lambdas)):
l = lambdas[i]
avg_err_tr = 0
avg_err_te = 0
for k in range(k_fold):
err = cross_validation_rr(y, x, k_indices, k, l, degree)
avg_err_tr += err[0]
avg_err_te += err[1]
rmse_tr.append(np.sqrt(2 * avg_err_tr / k_fold))
rmse_te.append(np.sqrt(2 * avg_err_te / k_fold))
helpers.visualization(lambdas, rmse_tr, rmse_te)
# find the best lambda
min_err_index = 0
for i in range(1, len(rmse_te)):
if rmse_te[i] < rmse_te[min_err_index]:
min_err_index = i
lambda_opt = lambdas[min_err_index]
x_poly = helpers.build_poly(x, degree)
w_opt, mse = imp.ridge_regression(y, x_poly, lambda_opt)
print(" lambda={l:.3f}, mse={mse:.3f}".format(mse = mse, l = lambda_opt))
#Training Accuracy
y_predicted = helpers.predict_labels(w_opt.T, x_poly)
accuracy = (list(y == y_predicted.flatten()).count(True))/len(y)
print(" accuracy={acc:.3f}".format(acc = accuracy))
ws = []
for k in range(k_fold):
loss_tr, loss_te, w = cross_validation(y, x, k_indices, k, lambda_,
degree)
losses_te.append(loss_te)
losses_tr.append(loss_tr)
ws.append(w)
return np.mean(losses_te, axis=0), np.mean(losses_tr,
axis=0), np.mean(ws, axis=0)
losses_te, losses_tr, w = cross_validation_ridge()
print(
f'Average Missclassification proportion on test folds was {losses_te}. On Train folds it was {losses_tr}.'
)
test_y, test_x, test_ids = load_csv_data(DATA_PATH + 'test.csv')
# replace missing values with means determined from training data
test_x, _, _, _ = normalize(test_x, col_mean, xmin, xmax)
# create final predictions on testing data and submission csv
y_pred = predict_labels(w, build_poly(test_x, degree))
create_csv_submission(test_ids, y_pred, DATA_PATH + 'inferred.csv')
print(
'Your final submission has been created and is called /data/inferred.csv')