Controlling expansion has been a key part of expl3 from day one. A basic expl3 function name such as \foo:nn shows how many unmodified braced arguments it takes: so called n-type arguments. We can then create variants, which can lead to expansion only once (o-type), to the value of a variable (V-type) or to the value retrieved by constructing the name of a variable and then finding the value (v-type). We can do the same with single-token (N-type) arguments, which are often themselves functions and can be given as a constructed name (c-type).

Right from the first version, siunitx has supported uncertainty values in numbers. Uncertainties are a key piece of information about a lot of scientific values, and so it’s important to have a convenient way to present them.

It is quite natural to think that separating a word up into individual characters is quite easy. It turns out that for the computer this isn’t really the case. If we look at a system that understands Unicode (like XeTeX or LuaTeX), most of the time one ‘character’ is stored as one codepoint. A codepoint is a single character entity for a Unicode programme. For example, if we take the input café, it is made up of four codepoints:

A topic that comes up for many LaTeX users is how best to mark up math mode in sentences: inline math mode. LaTeX offers three (!) official ways to do that

I mentioned recently that I’m working on features for siunitx v3.1. One area that I’ve now been able to commit is improvements to handling complex values.

I’ve now done 49 (!) minor releases of siunitx on the v3.0.x branch. These have addressed quite a few minor bugs: I expected to have to do a bit of work since the shift from v2 was quite major.

The third major release of siunitx was out in May, after the TeX Live 2021 DVD. That means it’s been picked up primarily by more active users: people who install TeX between the ‘fixed’ DVD releases (or who use MiKTeX). It also didn’t initially appear on Overleaf, as they take a while to test TeX Live images before making them public.

I’ve been meaning for a little while to look properly at my Jeykll theme for the site and tidy it up: it was a bit basic. Prompted in part by Will Robertson, I decided that now is the moment.

Usually, I keep my day job (as a university lecturer in chemistry) and my LaTeX work separate. Of course, I use LaTeX at work for things like lecture handouts, but most of the time the two areas don’t directly intersect.

With v3 of siunitx out, I am as expected getting quite a few questions about moving from v2. In the main, this is quite easy as there is a decent amount of compatibility code. Here, I’ll pick out a few cases where you might want some adjustments.