def split_data(X, y, split_ratio=0.2):
    """
    Split data into training and testing.

    :param X: X
    :param y: y
    :param split_ratio: split ratio for train and test data
    """
    split = X.shape[0] * split_ratio
    X_test = X[:split, :, :, :]
    y_test = y[:split, :]
    X_train = X[split:, :, :, :]
    y_train = y[split:, :]

    return X_train, y_train, X_test, y_test