曲线图形

In the first Chapter of this thesis, after a short review of the role of solid modellers in CAD and CAM, we explain the importance of robustness for curved or surfaced solid models.

本文将系统地研究区间曲线与曲面的逼近问题，对这些问题的研究，在计算机图形学和机械产品CAD中具有一定的理论价值和良好的应用前景。

In geographical information drawing, there are many random curves, like boundary lines, reivers, coasts and roads, etc.

地理信息图示中的很多图形要素均是随机曲线，如边界线、河流、海岸、道路等。

Explain how to draw the experimental curves. The advantage of using figure to expression experimental data is clearly,easy to compare, and easy to see the extreme value point and turning point, periodic rate and other properties in the data.

问题补充：说明如何绘制实验曲线实验数据用图形表示的优点是直观清晰，便于比较，容易看出数据中的极值点、转折点、周期性变化率以及其它特性。

Traditionally ellipsoids and hyperboloids are modeled as implicit surfaces or through the use of rational surface schemes. The existing methods for generating spheres or quadrics have shortcoming such as the rational parameterizations for these surfaces are non-uniform, the resulting scheme cannot represent these surfaces in their natural acr-length parameterization and the implementation of the scheme is complex.

长久以来，Subdivision方法对一些看似简单却又在计算机图形学中有着重要作用的曲线曲面的造型非常困难，即使是对简单的圆和球的生成也很困难，已有的一些生成球或二次曲面的Subdivision方法一般都有太复杂、不能自然弧长参数化或者计算量太大等缺点。

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。