def __init__(self, ly_min=0.0, ly_max=1.0, skew=0.5, threshold=1.0):
self.ly_min = float(ly_min)
self.ly_max = float(ly_max)
self.skew = float(skew)
self.threshold = float(threshold)
self.map = SectionMap(self.lx_min, self.lx_max, self.ly_min, self.ly_max, skew)
