当要消去的因子是一个基矢量时，用另一个基矢量来点乘，以得到克罗内克尔记号。

When the factor to be cancelled is a base vector we dot-multiply by another base vector to produce a kronecker delta.

youdao

这种方法是利用参考基点的笛卡尔坐标和参考基矢量的笛卡尔分量描述物体的位置与姿态。

This kind of method describes the position and attitude of objects by utilizing Cartesian coordinates of reference base points and Cartesian components of reference base vector.

youdao

然后从基类 UIComponent 扩展，并覆盖 updateDisplayList() 方法来绘制这个定制矢量图。

Then extend from the base class UIComponent, and override the updateDisplayList() method to draw the custom vector drawing.

youdao

You can pick your unit vectors, or what are called basis vectors, any way you like.

你可以任意选取单位矢量,或者也可以叫做基矢量,这都随便你

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