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Web stuff

MathJax hangout on air Q&A

I did a Google+ Hangout on Air Q&A session with MathJax’s Peter Krautzberger and’s Phil Schatz last Friday. We spent about an hour and a half answering questions and talking about the way we use MathJax.

It was a bit awkward, since I couldn’t see who was watching, and it wasn’t very clear how to interact with the audience apart from them submitting questions, but some people seem to have found it worthwhile.

For your entertainment, here’s the recording:

Peter wants to run more of these Q&As in the future. I’ll make sure to attend!

A bookmarklet to replace’s image-based maths with MathJax

I finally got fed up enough with’s blurry image-based maths rendering to write a bookmarklet which goes through the page replacing them with the equivalent MathJax code. I’ve added it to my MathJax bookmarklet installation page. Drag the “image replacement bookmarklet” to your bookmarks bar, go to a blog (I recommend Gowers’s Weblog), then click the “Replace image maths with MathJax” bookmarklet.

Update 19/09/2013: Following a suggestion by Peter Krautzberger, I’ve updated the bookmarklet to do the image replacement differently, so the images don’t disappear while MathJax is working. I’ve also made it work on Wikipedia.

Talk: Computability of Bass-Serre structures in the Grzegorczyk hierarchy

My chum the inimitable David Cushing has started a postgrad pure maths seminar at Newcastle. Because there are only a few pure postgrads here, he asked me to give a talk about the stuff I was looking at for the PhD I gave up on last year.

I’ve written a few posts here in the past about the Grzegorczyk hierarchy, computable groups, and so on, but I think this might be the first time I’ve presented my work to real people (apart from an impromptu hour-long braindump when one of the real seminar speakers cancelled and I decided to test my memory).

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Slides from a talk about zero-knowledge protocols

I’ve just given a talk at Newcastle’s maths & stats Postgraduate Forum about zero-knowledge protocols. I don’t know very much about them but it’s an interesting topic and something fairly accessible to an audience of non-pure mathematicians.

Click here to see the slides.

I used deck.js, along with the Computer Modern web fonts and MathJax, to make the slides. I think it looks pretty nice! I’ve also uploaded my template deck, in case you want to build on it for your own presentations. It’s a bit big because it contains all the files needed to display the Computer Modern fonts on any browser.

Using Computer Modern on the web

Computer Modern is the family of typefaces developed by Donald Knuth for TeX. It’s so good-looking that some scientists do research just so they can write it up in Computer Modern.

The cm-unicode project compiles versions of the Computer Modern fonts in a few formats, including TTF. I’ve run them through codeandmore’s @font-face kit generator to get all the weird formats that the various browsers insist on.

I’ve put up a page containing examples of each face in use and links to packages containing everything you need to use them.

Instant MathJax preview of LaTeX typed into HTML textareas

I’ve completely rewritten my write maths, see maths library to be a little jQuery plugin that attaches itself to editable areas on pages, like contenteditable elements, textareas, and input boxes. When your cursor is inside some LaTeX, a little preview box appears just above it with the LaTeX rendered through MathJax. I’ve made a demo page on GitHub, and the code itself is available there too. It also works in TinyMCE, if you’re into that sort of thing.

The first I thing I did with it was to write a WordPress plugin which applies the plugin to the comment boxes underneath posts (source code). I’ve installed it on this site and The Aperiodical, so you can use LaTeX with confidence, knowing that it’ll appear how you want on the page. Please try it in the comments box below!

A little applet to make maths for screengrabbing

Paul Taylor wanted an easy way to write some maths he could take a screengrab of, for use as an icon. Before I intervened he was doing something unnatural with wikipedia, so I wrote a little applet using MathJax: “make big maths“.

Quite a few tools like this exist, using mimetex or some other CGI tool to run LaTeX on a server and produce an image file. That’s far too slow and rubbish-looking for my liking, so I made my own with MathJax.

How to get beautifully typeset maths on your blog

Lots of people have blogs where they talk about maths. Lots of these people just use plain text for mathematical notation which, while it gets the point across, isn’t as easy to read or as visually appealing as it could be. MathJax lets you write LaTeX and get beautifully typeset mathematical notation. And it’s really really easy to set up: you just need to paste some code into the header of your blog’s theme. To make it really really really easy, I’ve written some very detailed instructions of what to do for each big blogging service. (If you’re reading this after I wrote it, which you definitely are, beware that the interfaces I describe may have changed, so the advice below might be inaccurate. If it is, or if you’re just having trouble following along, please leave a comment below.)

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