Direction vector

Run direction and orientation of 2D line

In mathematics, a direction vector that describes a line D is any vector

where $A$ and $B$ are two distinct points on the line. If v is a direction vector for D, so is kv for any nonzero scalar k; and these are in fact all of the direction vectors for the line D. Under some definitions, the direction vector is required to be a unit vector, in which case each line has exactly two direction vectors, which are negatives of each other (equal in magnitude, opposite in direction).

单词	Direction vector
释义	Direction vector 英语百科 Direction vector In mathematics, a direction vector that describes a line D is any vector where $A$ and $B$ are two distinct points on the line. If v is a direction vector for D, so is kv for any nonzero scalar k; and these are in fact all of the direction vectors for the line D. Under some definitions, the direction vector is required to be a unit vector, in which case each line has exactly two direction vectors, which are negatives of each other (equal in magnitude, opposite in direction).
随便看	brushback brush back brush backward lead brushbar brush barrel brushbars brush bath brush beater brush beef brush binder brush biopay brush biopsy brush biopsy through bronchofiberscope brush bit brush block brush boat brushboat brush body brush body preparing brush body, shoe brush, polishing brush brush bolt Brush border brush border adhesin brush border appearance brush border hydrolysis