def get_min_max_range(arr_1d, std_factor=2):
    """Get min max ranges for array, defined as so many standard deviations +/- from the mean

    Args:
        arr_1d (numpy.array): Numpy array over which values are calculated.
        std_factor (int, optional): The min / max ranges returned are this many std +/- the mean. Defaults to 3.

    Returns:
        double, double: min and max calculated values
    """
    arr_mean = arr_1d.mean()
    arr_std = arr_1d.std()
    min_val = arr_mean - arr_std * std_factor
    max_val = arr_mean + arr_std * std_factor
    return min_val, max_val