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Is there any small and simple program (or even library) that can render LaTeX locally as you type?

I'm looking for something pretty much like this page, which auto-renders immediately as you type, except that it:

  • Must not need any internet connection

  • Should be as "lightweight" as possible (it shouldn't even depend on a browser, if that can be avoided... a standalone executable would be ideal)

(The goal is to avoid going having to go through the pain of creating LaTeX documents every time you want to write a little expression to paste somewhere else, but without needing an internet connection or another program to run it.)

If there is even a C/C++-compatible library that could convert a basic LaTeX equation to a PNG file (or SVG or whatever), that would be fine too; I could write a front-end for it pretty easily.

barbara beeton
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user541686
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3 Answers3

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The website you point to is using MathJax to render the LaTeX. If you don't mind using a browser, then you can simply download MathJax, unpack the zip file, go into the test subfolder and open sample-dynamic.html in your browser. This is effectively an equation editor. You can make a custom web page to cater to your needs.

enter image description here

Note: As it is this requires you to hit the return key to render. That should be simple enough to alter. Grabbing the equation as a PNG could be a little more complex to achieve.

qubyte
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  • In terms of "lightweightedness", what is the size of the download? Also, would it be possible to modify the code to typeset the equation on-the-fly rather than pressing RETURN? These are just inquisitive questions... – Werner Feb 07 '12 at 07:13
  • Since the site that the question points to is using MathJax and updates on the fly, yes to the second question. The download is ~15MB, so it depends on your definition of light. Lighter than a full install of TeX Live anyway. ;) – qubyte Feb 07 '12 at 07:16
  • I kinda already knew about MathJax but was hoping for something more lightweight (15 MB is kinda huge for this, especially when combined with a > 20 MB browser)... +1 thanks anyway. – user541686 Feb 07 '12 at 08:23
  • @Mehrdad: The problem you're going to have is that TeX is simply big. If you want even a fraction of the functionality then I'm afraid you're stuck. Perhaps you can strip out some of the unnecessary fonts that come with MathJax. A modern system should include the necessary fonts without having to use them. You can also strip out docs and perhaps more stuff taking you down to 5MB. – qubyte Feb 07 '12 at 10:59
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    @MarkS.Everitt: Hmm... I might actually give that a try, thanks for the suggestion. – user541686 Feb 07 '12 at 11:06
6

Is there any small and simple program (or even library) that can render LaTeX locally as you type?

The only freely available program that I know of which can handle on-the-fly rendering of TeX and friends is LyX.

(The goal is to avoid going having to go through the pain of creating LaTeX documents every time you want to write a little expression to paste somewhere else, but without needing an internet connection or another program to run it.)

If there is even a C/C++-compatible library that could convert a basic LaTeX equation to a PNG file (or SVG or whatever), that would be fine too; I could write a front-end for it pretty easily.

As far as libraries go, you could look into running MathJax. This could be embedded into a C++ program using the WebKit browser or even into a command-line tool using a "headless" browser like PhantomJS. Some more options are listed in:

What parsers for (La)TeX mathematics exist outside of the TeX engines?

The issue that prevents a proliferation of good parsing libraries for TeX math is that TeX has a context-sensitive grammer that can be altered on the fly. Because of this, it is easy to come up with pathological examples that will confound any parser that is not TeX:

\catcode`/=13
\let/\over

$y = {-b \pm \sqrt{b^2 - 4ac}} / {2a}$

\end

Add users eventually wanting to use "a specialized macro from LaTeX package X" and the most robust contenter left is an actual TeX engine.

Community
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Sharpie
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The closest thing to your needs probably is latexmk. Every time you save your #.tex-file, latexmk runs LaTeX, pdfLaTeX and probably even LuaLaTeX, plus BibTeX, if you need that also. I propose to use Sumatra-PDF to view the PDF. This great piece of software does not lock the PDF, when opened, so latexmk can change the PDF and Sumatra-PDF will render it more or less immediately.

Maybe you can connect a second screen to your computer and have on one screen your *.tex-file and on the other the PDF.

Besides that: Compiling your document every second probably won't work, while you type. Any open bracket will cause an error.

Keks Dose
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  • What you describe, does only work with the -pvc option, or has the default behaviour been changed? – Speravir Feb 07 '12 at 18:37
  • @Speravir Yes, -pvc is needed, or more generally: you have to set up latexmk properly to use it the way I described. – Keks Dose Feb 08 '12 at 11:00