And when I am on the curve I am on the boundary of the surface, so there is a direction along the surface that is the curve and the other one is pointing into the surface.

当我在曲线上时，我是在曲面的边上的，所以一个是沿着曲面的边指，那个就是曲线的定向，另外一个就要指向曲面里面的那个方向。

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And we looked at the component of a vector field in the direction that was normal to the curve.

我们研究的是，向量场在曲线法向量方向的情况。

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Firstly, using the first order derivative of Gaussian function as the base wavelet, the direction Angle function of a planar curve was analyzed on multiple scales to obtain the candidates of corners.

使用高斯函数的一阶导数作为基本小波，对曲线的方向角函数进行多尺度小波分析得到候选点集，提出了四个筛选规则对候选点集进行逐步筛选得到正确角点集。

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