def METHOD_NAME(X):
    """
    Preprocessing of features (no dimensional reduction) using principal component analysis.
    Params:
        X: Array of features.
    Output: Tuple (processed array of features function that reduces dimension of array).
    """
    _, n = X.shape
    pca = PCA(n_components=n)
    x = pca.fit_transform(normalize(X))
    def transform(input):
        return pca.transform(normalize(input))
    return x, transform