We need Tex markup [duplicate]

Question

Possible Duplicate:
Can we turn off math-tex please?
Why doesn't maths render as maths?

... but, until we get it, I have created a GreaseMonkey script for use here.

http://userscripts.org/scripts/show/81977

To use the script, simply enclose the markup in dollar signs like so:

$\frac{1}{2}$

The script has some severe limitations in that it does not do recursive decent parsing. As such, it cannot handle this format:

$ \text{ $content$ } $

This is primarily of use for math markup, but will work for anything supported by these seven rendering services:

• Google Charts $\frac{1}{2}$ http://chart.apis.google.com/chart?cht=tx&chf=bg,s,FFFFFF00&chl=%5Cfrac%7B1%7D%7B2%7D
• 72 Pines $\frac{1}{2}$ http://tex.72pines.com/latex.php?latex=%5Cfrac%7B1%7D%7B2%7D
• CodeCogs.com $\frac{1}{2}$ http://latex.codecogs.com/gif.latex?%5Cfrac%7B1%7D%7B2%7D
• MathTran.org $\frac{1}{2}$ http://www.mathtran.org/cgi-bin/mathtran?D=1;tex=%5Cfrac%7B1%7D%7B2%7D
• MimeTeX $\frac{1}{2}$ http://www.forkosh.dreamhost.com/mimetex.cgi?%5Cfrac%7B1%7D%7B2%7D
• MathTeX $\frac{1}{2}$ http://www.forkosh.dreamhost.com/cgi-bin/mathtex.cgi?%5Cfrac%7B1%7D%7B2%7D
• Simto Equation Editor $\frac{1}{2}$ http://www.sitmo.com/gg/latex/latex2png.2.php?z=100&eq=%5Cfrac%7B1%7D%7B2%7D

Answer 1

Why do we need TeX markup?

Firstly, what is usually meant by this is "We need TeX mathematics markup" rather than the full power of TeX. That's subtly different.

Secondly, what benefit would that bring to this site? I can't actually think of one, but I can think of several reasons why it would be a bad thing:

1. It might interfere with quoting TeX markup that is meant to be left alone (it can quickly get annoying to have to put every TeX command in backticks)
2. Whatever method is used, it is likely to have its own idiosyncrasies and so it could become hard to distinguish errors due to TeX from errors due to the conversion method
3. If people need to show something that's compiled to demonstrate an error, then they should link to a PDF where they can be absolutely sure that what everyone else is seeing is what they mean them to see

(For comments on actually implementing this, see my comments to this question on the main site.)

Answer 2

Having now used the site a little, I can see that there is a case to be made for a way to included rendered TeX. I would argue that:

1. It has to be true TeX. Otherwise, we can't be sure that what we're seeing isn't some artifice of the method used to render it.
2. It has to be explicitly selected for. Otherwise, it's confusing for newcomers to have their code suddenly converted.
3. It has to be easy to separate from the Markdown markup. Otherwise, it gets confusing remembering what needs to be escaped and what not.

So here's a suggestion: a web-server that has a standard installation of TeXLive 2009 that can call tex, or one of its variants, on files uploaded. Somewhat similar to that done at the arXiv. But to encourage people to provide minimum working examples, there should be a quite low limit on file size. I would consider putting a limit on the number of pages rendered, perhaps 2 as sometimes issues are about differences between one page and another.

I would then have the server cache the result, either as a PNG (if small enough) and/or a PDF, and return a link to that cache, maybe using md5sum or something to generate a unique URL that isn't too bad. This could then be included back in the question/answer using the usual Markdown image syntax.

As well as a file upload method, there could be a short-cut whereby the contents of a textbox gets processed inside some standard setup.

Answer 3

The problem with every solution other than server-side TeX rendering is: this is a site about TeX and friends and examples should be generated by TeX and friends.

However, there is a slight problem: it's not only about equations, which can be rendered without a hinch as images. Most problems people have are those of positioning. That actually means that every example marked as "complete" in some way (i.e. not an excerpt) should be rendered on server to some sensible format, stored on some statically-deployable subdomain and made available in at least two formats: original rendering and a PNG thumbnail, the latter being a reduced rendering of a complete page in output format.

Implementing this stuff would probably begin with an installation of current TeXlive on some server. Each user should be able to mark some code as "to be rendered" and probably also specify the engine (ConTeXt, LaTeX, XeLaTeX, etc.) The following edge cases should be considered though:

1. "My DVI is broken but PDF using pdflatex is ok"
2. "This code used to work with MikTex version X, but doesn't on TeXlive 2009"

The easiest would probably be to go with the 80/20 rule and exclude such questions from being rendered.

Answer 4

I fee that this is a pretty important feature for the site, which is why I’m pushing the discussion.

While Andrew’s request would be the ideal, I believe that even an approximation would help a lot (and is more realistic to get). I’d like to point out that two of the potential problems he pointed out are trivial to solve:

Markdown can easily be extended to generate some kind of “TeX environment”, like the current code environment. There are tons of possibilities, the simplest being a dedicated <tex> pseudo-HTML tag. This would be completely unambiguous.

Here are a few posts that would benefit from some kind of rendering, just on the current top page of questions:

• How to deal with bibliography items containing long URLs?
• How to typeset Haskell ++ operator and friends?
• Bad positioning of math accents for the beamer standard font
• Space between emphasized word and parenthesis

Indeed, most of my own posts contain images of rendered LaTeX which are hosted off-site and might accidentally be taken offline by me in the future (I’m sloppy with my web resources). (Issue fixed.)

Answer 5

The #latex channel on irc.freenode.net has tex, latex and context bots which can generate pngs and svgs. I would be great when explaining and showing the differences between suggested approaches, as sometimes it is very subtle and not obvious from the markup.

E.g. explaing \phantom is best with two small samples/images then by saying ``it's like invisible ink"

Answer 6

The problem with this is that people using other browsers (like IE or Safari) see what looks like line-noise (although raw TeX markup is more acceptable on this Stack Exchange than on others). A better solution may be to use a service that compiles the equation to PNG and then host it using a service like TinyPic.

I put together a list of such compilation services on the statistical analysis stack exchange.

This way everyone gets to see what the equation looks like.

Answer 7

Well, I would argue about this.

1. Every code has to be debugged, which means that it is processed multiple times giving completely unnecessary load of the server.

2. As well, as mentioned by others, there will arise bugs of this system and questions on TeX.SX concerning only this system, which makes it real pain in the ass and kills the whole idea of this site as a "TeX wiki".

3. I believe that what we really need is

   • a good image storage (possibly like 10 images per user up to some reputation, then enlarging the number, or similar solution);
   • with automatic file.pdf->cropped_file.pdf->file.png (the middle part optional) conversion so that you can include "PDF" images and be happy;
   • these two feature would enable to quickly include any rendered material (equation, table, symbol, page), yet being sufficiently independent of any TeX-related problems on the server side.