Untitled

import numpy as np
from sklearn.datasets import load_breast_cancer
from sklearn.model_selection import KFold
from sklearn.metrics import roc_auc_score

def main(iworkmode):
    iscenario = 0  ## =0 step size enumration Question 3,
                   ## =1 iteration number enumeration, Question 4

    # Load the data
    X, y = load_breast_cancer(return_X_y=True)
    mdata, ndim = X.shape 
    y = 2 * y - 1

    if iscenario == 0:  ## Question 3, step size enumeration
        # List of step sizes
        neta = 10   ## number of different step sizes
        eta0 = 0.1  ## first step size
        leta = [eta0 * (i+1) for i in range(neta)]
        iteration = 50
    elif iscenario == 1: ## Question 4, iteration number enumeration
        # List of iteration numbers
        niteration = 10  ## number of different iterations
        iteration0 = 10  ## first iteration number
        literation = [iteration0 * (i+1) for i in range(niteration)]
        eta = 0.1

    nfold = 5         ## number of folds
    np.random.seed(12345)
    cselection = KFold(n_splits=nfold, random_state=None, shuffle=False)

    # Normalize the data
    X /= np.outer(np.ones(mdata), np.max(np.abs(X), 0))

    max_avg_score = -1  # Initialize with a low value
    corresponding_hyperparameter = None

    if iscenario == 0:
        for eta in leta:
            avg_score = 0
            for train_index, val_index in cselection.split(X):
                X_train, X_val = X[train_index], X[val_index]
                y_train, y_val = y[train_index], y[val_index]

                # Implement your logistic regression algorithm here
                # Train the model and compute the ROC-AUC score
                # Example: use scikit-learn's LogisticRegression

                from sklearn.linear_model import LogisticRegression
                model = LogisticRegression(C=1/eta, max_iter=iteration, solver='lbfgs')
                model.fit(X_train, y_train)
                predictions = model.predict(X_val)

                avg_score += roc_auc_score(y_val, predictions)

            avg_score /= nfold

            if avg_score > max_avg_score:
                max_avg_score = avg_score
                corresponding_hyperparameter = eta

    elif iscenario == 1:
        for iteration in literation:
            avg_score = 0
            for train_index, val_index in cselection.split(X):
                X_train, X_val = X[train_index], X[val_index]
                y_train, y_val = y[train_index], y[val_index]

                # Implement your logistic regression algorithm here
                # Train the model and compute the ROC-AUC score
                # Example: use scikit-learn's LogisticRegression

                from sklearn.linear_model import LogisticRegression
                model = LogisticRegression(C=1/eta, max_iter=iteration, solver='lbfgs')
                model.fit(X_train, y_train)
                predictions = model.predict(X_val)

                avg_score += roc_auc_score(y_val, predictions)

            avg_score /= nfold

            if avg_score > max_avg_score:
                max_avg_score = avg_score
                corresponding_hyperparameter = iteration

    if iscenario == 0:
        print(f"Maximum average score: {max_avg_score:.2f}")
        print(f"Corresponding step size: {corresponding_hyperparameter:.2f}")
    elif iscenario == 1:
        print(f"Maximum average score: {max_avg_score:.2f}")
        print(f"Corresponding iteration number: {corresponding_hyperparameter}")

if __name__ == "__main__":
    main(0)  # Specify the scenario (0 for step size, 1 for iteration number)