I have two 3D vectors in 3D line plot in Matlab. How I can specify an angle name between them? And also an angle between any two crossing lines?
What do you mean by an "angle name"? If you wanna save the angle value under a variable: mathematically, it will be a map/function. you can save the values onto an array indexed by the vectors or lines you have for efficient recalling. If you are asking for a method to obtain this angle, i.e. the function mentioned above, you can use dot product to do it. 

