Implementations of R^2 Score

r2_scores.py

def r2_score(y_true, y_pred):
    """Implements the Coeffecient of Determination, R^2 or R-squared"""
    SS_res =  kb.sum(kb.square(y_true - y_pred))
    SS_tot = kb.sum(kb.square(y_true - kb.mean(y_true)))
    return (1 - SS_res / (SS_tot + kb.epsilon()))


def inverse_r2_score(y_true, y_pred):
    """Implements the inverse Coeffecient of Determination, R^2 or R-squared"""
    SS_res =  kb.sum(kb.square(y_true - y_pred))
    SS_tot = kb.sum(kb.square(y_true - kb.mean(y_true)))
    return 1 / (1 - SS_res / (SS_tot + kb.epsilon()))


def negative_r2_score(y_true, y_pred):
    """Implements the negative Coeffecient of Determination, R^2 or R-squared"""
    SS_res =  kb.sum(kb.square(y_true - y_pred))
    SS_tot = kb.sum(kb.square(y_true - kb.mean(y_true)))
    return -1 * (1 - SS_res / (SS_tot + kb.epsilon()))