def get_elapsed_time(time_in_seconds):
    """ Helper function to get elapsed time in human-readable format.

    Parameters
    ----------
    time_in_seconds : float
        runtime, in seconds

    Returns
    -------
    str
        formatted human-readable string describing the time
    """
    if time_in_seconds < 60:
        return '%.1f seconds' % time_in_seconds
    elif time_in_seconds < 3600:
        return '%.1f minutes' % (time_in_seconds / 60)
    else:
        return '%.1f hours' % (time_in_seconds / 3600)
