# What's is the best way to indicate a vector

1. Mar 12, 2015

### SSDdefragger

Personally I indicate vectors as a putting bar on a letter, but some people just underline it or put an arrow above it. What's your way of doing so?

2. Mar 12, 2015

### Suraj M

arrow on top. works perfectly!

3. Mar 12, 2015

### Silver_rose

I use the arrow and it seems like it's pretty standard notation from all of my textbooks to do it that way, so that's how I do it.

4. Mar 12, 2015

### Quantum Defect

Arrow for me, too. Bar on top is also used for the average/mean.

5. Mar 13, 2015

### SSDdefragger

I am looking for time efficient and yet easily recognizable and good looking method. Any suggestions?

6. Mar 13, 2015

### Suraj M

Most of us use the arrow on the top, i don't see a more time efficient method. What do you have in mind? What do you feel is comfortable?

7. Mar 13, 2015

### SSDdefragger

It is too tedious to do so, and if you are going too fast they become like an mess on the top of a bar. Arrows are definitely not the best choice for me.

8. Mar 13, 2015

### Pythagorean

Arrow on top. If the arrow is going to get in the way, I capitalize and doublestrike one of the strokes, or bold the lowercase.

9. Mar 13, 2015

### Enclose

I also use an arrow on top, I don't see how it can be more time efficient or more easily recognizable.

But instead of an arrow like this --> with a v-shaped head I only give it one stroke to the top like in this picture:

An arrow like this is done in 1 smooth pen-movement, yet obvious and neat.

10. Mar 13, 2015

### DrGreg

What people prefer will probably depend on how they were taught in the past.

I always use underlining (W = Fx) in handwriting and bold non-italic font $\left( W = \textbf{F} \cdot \textbf{x} \right)$ when typing.

I've also seen lecturers use a "wavy underline" something like this:

x
~​

11. Mar 14, 2015

### Steyn11

A vector arrow (with arrowhead) is drawn in a specified direction. The vector arrow has a head and a tail.

12. Mar 14, 2015

### leroyjenkens

I give each of them a thought bubble that says "I'm a vector."

13. Mar 14, 2015

### Staff: Mentor

That depends on the purpose. What I use:
Calculate something quickly on paper/whiteboard: usually no special mark, unless it would be really confusing without, then they get an arrow (a real one or the one from post 9).
Write something down: \vec: $\vec{a}$.

14. Mar 14, 2015

### robphy

Surprised no one chimed in with "use an [abstract] index": $v^a$
(Oh, this isn't the Relativity forum :) )

15. Mar 14, 2015

### DrGreg

If we're going to go down that route, there is Dirac notation $|\psi\rangle$. (Oh, this isn't the Quantum Physics forum.)

And some do not use any special notation at all, using the same typography for vectors and scalars alike. (Oh, this isn't the Linear Algebra forum.)

16. Apr 27, 2015

### mpresic

I took a class in elasticity in 1982, and the professor always used a curly symbol (a tilda) over the symbols (letters.) which were vectors. I never asked him why, but he was in the minority of the professors who used arrows, bars, over or under the letters. Five years later I was taking electromagnetics with a professor who also used the tildas above the letters. I never asked him about the notation, but one day, he volunteered why he did this.
It seems like in the old days, the tilde over the symbol indicated a request to the (printer) or typesetter to "use bold-faced type". He told me he could send his notes directly to a printer if he so desired, since by learning to use this notation, he was automatically preparing his manuscript to be printed.