'Sets up the list data structure needed for calculation.'

def preProcess(self, front):

    dimensions = len(self.referencePoint)
    nodeList = _MultiList(dimensions)
    nodes = [_MultiList.Node(dimensions, point) for point in front]
    for i in xrange(dimensions):
        self.sortByDimension(nodes, i)
        nodeList.extend(nodes, i)
    self.list = nodeList
