Introducing LaTeX Math Typesetting

[chroot]

Originally posted by lethe
can we make feynman diagrams?

Not yet. I have considered adding the feynmf package, but, since it uses metafont, it would involve adding an additional stage to the image generation process. I'm not sure I want to go through all that trouble!

- Warren

 

[lethe]

Originally posted by chroot
Not yet. I have considered adding the feynmf package, but, since it uses metafont, it would involve adding an additional stage to the image generation process. I'm not sure I want to go through all that trouble!

- Warren

stop being so lazy!

just kidding, chroot.

actually, i just tried to get feynmf working on my computer, and failed. grr...

so i can sympathize.

 

[Hurkyl]

Just wondering!

$$\ddot{\smile}}$$

 

[Bob3141592]

I seem to be having a problem generating "n choose m"

Let's see if it works better here

$$x=({\colv{n}{m}})$$

Did that work?

 

[Bob3141592]

What's this? The sample I used as my template before just used the \colv command to line up two expressions over each other, but if I click the sample above that, I se a \newcommand statement that uses an array construct. Aha! Let's see if I can do that myself, as in


$$\newcommand{\colv}[2] {\left(\begin{array}{c} #1 \\ #2 \end{array}\right)}X = {\colv{n}{m}}$$

I hope that does the trick!

 

[Bob3141592]

Yes! Hallelluah! Now, let's see if that new command works as the first nonprintable line in a post and applies throughout it.

no, it's a transient macro. It has to go on every tex statement and gets forgotten on the /tex. Too bad.

$$\newcommand{\colv}[2] {\left(\begin{array}{c} #1 \\ #2 \end{array}\right)}\colv{n}{m} = \frac{n!}{(n-m)!m!}$$

$$\newcommand{\colv}[2] {\left(\begin{array}{c} #1 \\ #2 \end{array}\right)}\colv{n}{m} = \colv{n}{n-m}$$

Plus, it is so easy to mistype a brace as a parentheses! I hate it when that happens.

But, at least that's one problem down. Onwards to the prefix superscript next.

 

[master_coda]

If you want choose notation, just use

$$\binom{n}{m}=\binom{n}{n-m}$$

 

[Bob3141592]

This is a test - and a place to make experimental edits. I'll remove most of this post and post it with explanatory comments in the general math folder later.

Editing a long post doesn't always work (get a lot of "website not responding" errors). Let's see if shortening the post helps.

tbd

 

[Hurkyl]

You know, it doesn't all have to be written on one line.

 

[Bob3141592]

Originally posted by Hurkyl
You know, it doesn't all have to be written on one line.

Perhaps not, but it's been a fun (and frustrating!) exercise to learn LaTex, and get it to do exactly what I want it to. If I make compromises before I learn how to do it, I'll never learn what it's capable of.

 

[Bob3141592]

Originally posted by master_coda
If you want choose notation, just use

$$\binom{n}{m}=\binom{n}{n-m}$$

Thanks, Coda. That's much easier!

 

[Hurkyl]

I mean your actual LaTeX source code can be written across several lines, making it easier to read sometimes.

 

[Bob3141592]

Okay, back to experimenting/debugging tex:

Got it. Oh, happy day...er.. night.

 

[master_coda]

You do it like this:

$$3^n = \sum_{m=0}^n \left( \binom{n}{m} \cdot \sum_{p=0}^m \binom{m}{p} \right)$$

 

[Bob3141592]

Originally posted by master_coda
You do it like this:

I see. The \left and \right are generic, and you ave to supply the character specific delimiter following.

Thanks again!

I do wish LaTex had error messages, giving hints aout why it's parser is bailing out, but I guess that's a bit much to ask for. Ah well, if it was easy, anybody could do it.

 

[chroot]

Originally posted by Bob3141592
I see. The \left and \right are generic, and you ave to supply the character specific delimiter following.

Thanks again!

I do wish LaTex had error messages, giving hints aout why it's parser is bailing out, but I guess that's a bit much to ask for. Ah well, if it was easy, anybody could do it.

That sort of output IS generated by the latex program itself -- but getting that parsed into the PHP output would be a bear, basically.

I also have to add the fact that LaTeX errors are usually pretty unhelpful anyway, so there doesn't seem to be much reason to provide it for the user.

- Warren

 

[Bob3141592]

I've seen &=& used, but I don't understand the difference it makes. Is there a simple explanation? What's the & do in general, if it has a general interpretation.

This stuff is great. Not easy, I must admit, but definitely worth it.

 

[master_coda]

Usually & acts as an alignment character. For example, in:

$$\begin{align*} D^{-\nu}e^{at}&=\frac{1}{\Gamma(\nu)}e^{at}\int_0^t x^{\nu-1}e^{ax}\;dx \\ &=E_t(\nu,a) \end{align*}$$

the & character specifies how the columns are supposed to be lined up. Note that \\ specifies the end of each line.

The & character is also used to separate columns in a matrix. If someone is using &=& to line up their equations instead of &=, they may be using matrices to align equations.

 

[Tron3k]

Just figuring this out...

$$y = a x^2 + b x + c$$
$$x = \frac{-b \pm \sqrt{b^2 - 4 a c}}{2 a}$$

 

[Silverious]

hmmmm

$$d = \frac{1}{2}a t^2$$

$$\sum F = ma$$

$$\lim_{x\rightarrow c} f(x) = L$$

$$0 \leq |x - c| \leq \delta$$

$$|f(x) - L| \leq \epsilon$$

$$F_g = G \frac{m_1 m_2}{d^2}$$

$$this = fun$$

 

[Allegro]

Let's give it a try (using TexAide):

$$\frac{{\sqrt s }}{{s - a^2 }}$$





$$\displaystyle{\int_2^4 {\left[ {8(t - 2)} \right]^{-0.5} dt = } \left[ {\frac{1}{{\sqrt 2 }}(t - 2)^{0.5} } \right]_2^4 = 1}$$


With compliments to TeXaide.

 

[phoenixthoth]

how do i go about installing such a thing on my discussion forum? any help much appreciated!

 

[Allegro]

TeXaide

Hello phoenixthoth,

#1.
Download TeXaide:
http://www.mathtype.com/en/products/TeXaide/

#2.
Type in an equation in TeXaide and copy it.

#3
Paste it in your message on the Physics Forum,then go to my previous message and click on quote,then you can see how it is done.

Delete all superfluous characters.


Best regards.

 

[phoenixthoth]

Originally posted by Allegro
Hello phoenixthoth,

#1.
Download TeXaide:
http://www.mathtype.com/en/products/TeXaide/

#2.
Type in an equation in TeXaide and copy it.
Paste it in your message on the Physics Forum,between:
First type: $$\displaystyle{....}and finish with$$
where ... is your equation.
Delete all superfluous characters.

#3.
Go to my previous message and click on quote,then you can see how it is done.

Best regards.

how do i go about installing such a thing on my discussion forum? any help much appreciated!

thanks for trying to help but that wasn't my question. let me try to be more careful.
0. i already know how to make equations appear on this forum.
1. i have my own discussion forum.
2. i want to install something that will enable me to do what i can do on this forum on that forum.

i tried mimetex (from http://www.forkosh.com/htdocs/mimetex.html), but I'm having trouble compiling their source files into a mimetex.cgi file. it would help trememdously to just have a copy of that cgi file in question so that i can put it on my server. when i tried compiling their source files, i got a bunch of errors that i suspect are related to the fact that I'm running windows or perhaps the compiler I'm using. I'm trying to get the anti-aliasing gif version to work by entering
cc -DAA mimetex.c gifsave.c -lm -o mimetex.cgi
but it gives lots of errors.

so if you know anything on how to install an equivalent gif generator that uses html, let me know. any help is appreciated!

 

[Hurkyl]

Oh $no$! The inline $TeX$ no ^longer is aligned!

 

[chroot]

What in the world are you doing? It works fine for me... $\vec F = m \vec a$

And how about this? $\TeX$

If you put random text in, though... $hmmm who knows?$

- Warren

 

[Hurkyl]

It's because I've written superscripted normal text.

 

[chroot]

Originally posted by Hurkyl
It's because I've written superscripted normal text.

Oh, of course... hmmm, yeah. There's really no way around that.

- Warren

 

[master_coda]

Originally posted by chroot
Oh, of course... hmmm, yeah. There's really no way around that.

- Warren

There really isn't any reason you would want superscripted text and tex in the same message anyway.

 

[Hurkyl]

I put a footnote in one of my messages. I had an itex formula in it, and I tend to put my footnote tags in superscripts¹. Thus, the bug was discovered.



1: such as this one

 

[lethe]

what is going on with TeX today? is it broken?

see this thread

 

[lethe]

let's see if it works over here:

$$\int_M d\omega=\int_{\partial M}\omega$$

 

[chroot]

lethe, your link is apparently not valid. What is happening? As far as I know, $\TeX$ is working fine.

- Warren

 

[lethe]

Originally posted by chroot
lethe, your link is apparently not valid. What is happening? As far as I know, $\TeX$ is working fine.

- Warren

this morning, it seemed like LaTeX wasn't working. i guess i linked to a post that i later deleted or something. i guess that is why the link i gave didn't work (although i don't think a broken anchor is usually enough to break a link, but whatever.)

anyway, try this link. look at matt grime's post near the bottom.

everywhere there should be a LaTeX image, intsead, you get "latex still being generated, please reload" messages. i was getting the same thing in my posts, which i later deleted in order to try to recify the problem.

at any rate, whatever the problem was, it seems to be fixed now, although you can still see the weird messages now.

 

[Hurkyl]

More misformatting

I can't figure out what's going on with this one (though I haven't tried a lot)

Using this theorem, if $x^3 - x^2 - 8x + 12$ has a rational root, then it can be written in the form $p/q$ where $p \in \{1, -1\}$ and $q \in \{1, -1, 2, -2, 3, -3, 4, -4, 6, -6, 12, -12\}$. Only 12 possibilities to try, so if one exists you can find it by exhaustion.