def shapefunc(self, y):
        '''Take y and return a radius for the location of the foliage cluster.

        If no foliage cluster is to be created, return None
        Designed for sublcassing.  Only makes clusters close to the trunk.
        '''
        if random() < 100. / (self.height ** 2) and y < self.trunkheight:
            return self.height * .12
        return None
Take y and return a radius for the location of the foliage cluster.

        If no foliage cluster is to be created, return None
        Designed for sublcassing.  Only makes clusters close to the trunk.
        
stock-filters/Forester.py