Learn Mandatory LaTeX with PF: A Step-by-Step Guide

[chroot]

Originally posted by enigma
Greg, Warren,

I think that the intro thread which Warren posted should be made into a general announcement to all forums.

Most likely -- I can't do that though.

(except I currently have access to the entire site's code... supermegalomentor, here I come! )

- Warren

 

[Ambitwistor]

ALT tags

Sometimes the equation images take a while to load. Perhaps the TeX source could be squished into an ALT tag for the browser to display while it's loading the images (for those browsers that do that)?

 

[chroot]

Originally posted by Ambitwistor
Sometimes the equation images take a while to load. Perhaps the TeX source could be squished into an ALT tag for the browser to display while it's loading the images (for those browsers that do that)?

The browser does not display alt tags for images that are loading, it displays them for images that are unloadable -- in other words, images that don't exist on the server.

Are you saying it takes a long time to view a page that has TeX equations on it, because the image files take time to download? Or do you mean it takes time for a newreply (or editpost) operation to complete for a post with images in it?

- Warren

 

[ahrkron]

Wolfenstein parameterization:

[tex]
V = \left( \begin{array}{ccc}
1-\frac{1}{2}\lambda^2 & \lambda & A\lambda^3(\rho-i\eta) \\
-\lambda & 1-\frac{1}{2}\lambda^2 & A\lambda^2 \\
A\lambda^3(1-\rho-i\eta) & -A\lambda^2 & 1
\end{array} \right) + {\cal O}(\lambda^4)
[/tex]

 

[chroot]

ahrkron,

Post your examples in the general physics thread. :) Looks very pretty! I thought Wolfenstein was a video game.

- Warren

 

[Ambitwistor]

The browser does not display alt tags for images that are loading, it displays them for images that are unloadable -- in other words, images that don't exist on the server.

Some browsers do display ALT tags for images that are loading, and then replace them with the actual images after they have loaded.

Are you saying it takes a long time to view a page that has TeX equations on it, because the image files take time to download?

Yes.

 

[chroot]

Originally posted by Ambitwistor
Some browsers do display ALT tags for images that are loading, and then replace them with the actual images after they have loaded.

Okay -- well, the images already have an alt tag -- so if your browser is not displaying it, I don't know what to tell you.

Yes.

That's surprising. I chose the converters and formatting specifically to limit file sizes. In fact, the largest equation png file generated so far is just a hair over two kilobytes -- files of this size shouldn't be a problem on even an ancient phone modem. (Each image would take about half a second to download.)

As far as I can tell, the images haven't slowed my page loads noticeably at all.

What browser, OS, and internet access medium are you using?

- Warren

 

[Ambitwistor]

Originally posted by chroot
Okay -- well, the images already have an alt tag -- so if your browser is not displaying it, I don't know what to tell you.

Oh. Heh. My browser at home does that, but I never actually checked to see if this one does (I just started using it).

As far as I can tell, the images haven't slowed my page loads noticeably at all.

Well, my page loads are always slow, even over broadband ... I don't think it's due to image size, but due to the fact that each HTTP request stalls briefly while connecting. (So the total load time is proportional to number of images, not size. It can take a number of seconds just to load a forum page with all the little icons.) I don't think there's anything you can do about that.

 

[chroot]

Originally posted by Ambitwistor
Oh. Heh. My browser at home does that, but I never actually checked to see if this one does (I just started using it).

Well, my page loads are always slow, even over broadband ... I don't think it's due to image size, but due to the fact that each HTTP request stalls briefly while connecting. I don't think there's anything you can do about that.

Are you using a proxy server? Do you just happen to have some very slow link in your traceroute to physicsforums.com?

- Warren

 

[ahrkron]

Originally posted by chroot
Post your examples in the general physics thread. :) Looks very pretty! I thought Wolfenstein was a video game.

I knew the game too. I should have brought it up with him sometime.

Ok, General Physics, here it goes!

 

[Ambitwistor]

Originally posted by chroot

Are you using a proxy server? Do you just happen to have some very slow link in your traceroute to physicsforums.com?

No, I'm not using a proxy. My traceroute isn't bad, and I get 85 ms pings. It's probably the browser (Konqueror). I was using Mozilla, but I mangled some of my libraries beyond the current limits of my patience to fix them, so it doesn't work right for now.

 

[chroot]

Originally posted by Ambitwistor
No, I'm not using a proxy. My traceroute isn't bad, and I get 85 ms pings. It's probably the browser (Konqueror). I was using Mozilla, but I mangled some of my libraries beyond the current limits of my patience to fix them, so it doesn't work right for now.

Yeah, it's entirely possible your browser is opening new connections for each and every HTTP request -- and only opening one connection at a time. Ack!

- Warren

 

[ahrkron]

Tests...

[tex]
\newcommand{\colv}[2] {\left(\begin{array}{c} #1 \\ #2 \end{array}\right)}
L_L &=& \left(
{\colv{\nu_e}{e}}_L,
{\colv{\nu_\mu}{\mu}}_L,
{\colv{\nu_\tau}{\tau}}_L\,
\right), \qquad Y_L = -\frac{1}{2}
[/tex]

[tex]
\newcommand{\colv}[2] {\left(\begin{array}{c} #1 \\ #2 \end{array}\right)}
Q_L &=& \left(
{\colv{u}{d}}_L,
{\colv{c}{s}}_L,
{\colv{t}{b}}_L\,
\right), \qquad\quad\ Y_Q = \frac{1}{6}
[/tex]

 

[Ambitwistor]

Yeah, it's entirely possible your browser is opening new connections for each and every HTTP request -- and only opening one connection at a time.

I hope not! That's so 1995.

 

[Monique]

OK, my attempt to make a chemical equation::

[tex]^{33}_{17}Cl^16~\xrightarrow{n,n)~^{31}_{15}P^{16}~+~^4_2He^2[/tex]

 

[Monique]

ahhh! why!?

breaking it down::


[tex]^{33}_{17}Cl^{16}[/tex]

[tex]\xrightarrow{n,n}[/tex]

[tex]^{31}_{15}P^{16}[/tex]

[tex]^4_2He^2[/tex]

[tex]^{33}_{17}Cl^{16} ~ \xrightarrow{n,n) ~ ^{31}_{15}P^{16} ~ + ~ ^4_2He^2[/tex]

 

[Monique]

ok, I am probably putting the spaces or the + in in the wrong way?

 

[Monique]

[tex]^{33}_{17}Cl^{16}\xrightarrow{n,n)^{31}_{15}P^{16}+^4_2He^2[/tex]


..wtf! :P ?

I don't see what's wrong with this.. it worked individually?

[tex]^{33}_{17}Cl^{16}~\xrightarrow{n,n}~^{31}_{15}P^{16}~+~^4_2He^2[/tex]

ah, a wrong bracket..

 

[Monique]

COOLLLL!

 

[Ambitwistor]

[tex]
\newcommand{\atom}[4]{{}^{#1}_{#2}#3^{#4}}

\atom{33}{17}{Cl}{16} \xrightarrow{n,n} \atom{31}{15}{P}{16} + \atom{4}{2}{He}{2}
[/tex]

 

[Monique]

what happened there?

 

[Monique]

I also made a sticky in Chemistry, since it is very usefull to be used there too, maybe I should lock it an provide a link to the General Physics thread??

 

[Ambitwistor]

Originally posted by Monique
what happened there?

I have no idea. The page looks really messed up, but when I edit my post, the code looks okay. I should try again ...

 

[Ambitwistor]

Another attempt:

[tex]
\newcommand{\atom}[4]{{}^{#1}_{#2}#3^{#4}}

\atom{33}{17}{Cl}{16} \xrightarrow{n,n} \atom{31}{15}{P}{16} + \atom{4}{2}{He}{2}
[/tex]

 

[chroot]

Post the code with [ tex] and [ /tex], with spaces instead, so I can see it.

- Warren

 

[Ambitwistor]

This worked fine when I tried it in actual LaTeX, but it seems to choke here:

[ tex ]
\newcommand{\atom}[4]{{}^{#1}_{#2}#3^{#4}}

\atom{33}{17}{Cl}{16} \xrightarrow{n,n} \atom{31}{15}{P}{16} + \atom{4}{2}{He}{2}
[ /tex ]

 

[Ambitwistor]

Originally posted by Monique
[ tex ]^{33}_{17}Cl^{16}~\xrightarrow{n,n}~^{31}_{15}P^{16}~+~^4_2He^2[ /tex ]

You don't need all the tilde (~) characters ... they force a non-breaking space to prevent word wrap, but that's not an issue for a single line.

It's also customary not to leave ^ or _ dangling after nothing ... put a {} before them.

[tex]{}^{33}_{17}{Cl}^{16} \xrightarrow{n,n} {}^{31}_{15}P^{16} + {}^4_2He^2[/tex]

 

[Ambitwistor]

It seems not to like the [4] ... or rather, the [ 4 ] ...

 

[chroot]

I can't even get your code to work properly in tex on my local machine...

I'm trying

\newcommand{\atom}[4]{{x}^{#1}_{#2} {#3}^{#4}}

\atom{33}{17}{Cl}{16}
\xrightarrow{n,n}
\atom{31}{15}{P}{16} + \atom{4}{2}{He}{2}

I'll have to look into what's making it fail.

- Warren

 

[chroot]

I never consider people putting "smilie" code inside [ tex ] brackets -- I may need to change the precedence of the parsing code to prevent this. I'll let you know -- right now I don't have access to the site's code.

- Warren

 

[Ambitwistor]

Originally posted by chroot
I can't even get your code to work properly in tex on my local machine...

Works fine on mine ... Are you using latex (not tex), and including amsmath? Did you enclose the second line (the actual equation, after the macro definition) in a displaymath environment like $$...$$? What's the error?

I'm trying

\newcommand{\atom}[4]{{x}^{#1}_{#2} {#3}^{#4}}

\atom{33}{17}{Cl}{16}
\xrightarrow{n,n}
\atom{31}{15}{P}{16} + \atom{4}{2}{He}{2}

You've got an extra x in there ... it's supposed to be {{}^{#1} ... and so on. Otherwise, that's what I have.

 

[Monique]

[tex]\frac{[A^-]}{[HA]}[/tex]

 

[chroot]

Originally posted by Ambitwistor
Another attempt:

[tex]
\newcommand{\atom}[4]{{}^{#1}_{#2}#3^{#4}}

\atom{33}{17}{Cl}{16} \xrightarrow{n,n} \atom{31}{15}{P}{16} + \atom{4}{2}{He}{2}
[/tex]

 

[chroot]

Originally posted by Ambitwistor
Another attempt:

[tex]
\newcommand{\atom}[ 4 ]{{}^{#1}_{#2}#3^{#4}}

\atom{33}{17}{Cl}{16} \xrightarrow{n,n} \atom{31}{15}{P}{16} + \atom{4}{2}{He}{2}
[/tex]

 

[chroot]

Okay Ambi

It's the [ 4 ] that's causing problems, since it's being parsed by the smilie parser before being sent to latex. Here are two solutions:

1) Write [ 4 ] with spaces inside the tag, so the smilie parser won't touch it. LaTeX doesn't care about spaces.

2) Disable smilies in the post to stop the smilie parser from messing with it.

I'll update the code to put the smilie parser AFTER the latex parser when I get a chance.

- Warren