def get_three_level_class(value, red_thresh, yellow_thresh):
    """
    Map a continuous value to a three level (green, yellow, red) classification in which intermediate ("yellow")
    values are tagged with class -1. The idea is that these values will be removed from the data set.
    """
    if value >= red_thresh:
        return 1
    elif value < yellow_thresh:
        return 0
    else:
        return -1