拐结点

In this paper, the method, which is based on the theory of envelope and continuous map, is investigated.

文中用此方法分析了一些曲线的重要几何性质，即曲线段上含有尖点、重结点和拐点以及不含这些点的用控制顶点相对位置表示的充分必要条件。

Introduced is a kind of space uniform rational spline curve, which possesses tension parameters and is based on hyperbolic spline functions.

引入了基于双曲样条函数的、具有张力参数的空间有理等距节点样条参数曲线，给出了这种曲线在每个样条子区间上为挠曲线段的充分必要条件；分析了这种挠曲线段没有尖点、重结点和泛拐点的特性；因而在用于空间曲线几何造型时可避免奇异性。

Hence the study of geometric properties, which include the distribution of singular and inflection points and the convexity of parametric curves, is the key for designer to control the curves shape.

在计算机辅助几何设计的光顺曲线造型中，不希望曲线带有二重结点、尖点及多余拐点，因此对参数曲线的几何性质(包括奇、拐点分布及凸性等)的研究是控制其曲线形状的关键。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。