Re: vector notation

[Larry Smith <Larry.Smith@SNOW.EDU>]

At 6:36 PM -0400 7/20/04, Gerd Kortemeyer wrote:
> Hi,
>
> On Jul 20, 2004, at 5:09 PM, Larry Smith wrote:
> >  I always thought the vector arrow over the letter (or the squiggly
> >  under
> >  it) was employed in handwritten work precisely because it is hard to do
> >  boldface by hand.
>
> And I always thought that boldface or italic are used because the
> vector arrow is not available in many text processors

I'm pretty sure it is the other way around.  I found 2 or 3 other
"authoritative" sources that concur that vectors should be boldface
italic (including the ISO).

>  - not everybody uses LaTeX, like they should :-)

I agree.  I use LaTeX.  In fact, it was in one of my LaTeX books that
I found reference to the ISO guidelines that vectors should be
boldface italic.

>   \vec{a} produces an arrow.

Yes, and that is easier (shorter) than \boldsymbol{a}, so maybe
Knight is just lazy.

> I prefer the vector arrow in both printed and handwritten.

Maybe the standards will change to agree with you some day.

> Unit vector have the hat instead.

Agreed.

At 4:25 PM -0700 7/20/04, Roger Haar wrote:
>         Certainly my preference for teaching, is the
> arrow.  My reasons include:
>
> 1. On the board or overhead I cannot do boldface.
> 2. Students when working problems cannot do
> boldface. So teach them in the manner in which
> they will be working.

Agreed.  That was part of the original post.  When writing by hand
(including chalkboard or overhead) we use arrows over the symbols (or
squigglies under).  We model that on the board so students will do it
on their homework.

But it is because neither of us can do it the typesetting way.

> 3. When reading boldface impies to the student
> emphasis not a vector.

I question whether a single letter in boldface italic, especially in
a math context, implies emphasis.

> But using something that is
> new and unique may at least hint different.
>
>
>         The rules for typesetting are quite old and
> predate much of the modern wordprocessing.  Also
> they might have to increase the line spacing a bit
> to fit in the arrows.

This is true, but doesn't mean the rules necessarily fall by the
wayside.  Maybe the question becomes a pedagogical one as well as a
standards one.  Modern technology (i.e. LaTeX) allows arrows as
easily as boldface; maybe the standard will change.  Until it does...

>         Of course, Knight is letting the application be
> his guide in what he does.  We are not training
> students in introductory classes to produce
> publications.

But we are training them to read them.

Larry