def smooth_series(radius, col):
    """
        Generates "smoothed" copy of input data by applying a rolling mean of the requested radius.

        Args:
            radius (int): number of values to include in rolling mean
                        (e.g. radius = 1 means average values i, i-1 and i+1)
            col (pd.Series): column data to be smoothed
    """

    # Return original column if radius is less than 1
    if radius <= 0:
        return col

    window = (radius * 2) + 1
    return col.rolling(window, min_periods=1, center=True).mean()