Thanks @rnd-debug , this PR looks good and ready to merge 👍 . Great that you've added support for units. A function rotate(w, theta) on top of this will make this really interesting!

* should I provide a "complete Latex support"? For the moment, `toTex` will convert to `mathrm`.

I'm not sure what you mean with "complete" Latex support. Isn't rotationMatrix just a regular function like say sin? In that case we could render it just like other functions as \rotationMatrix\left(...\right). Or is there a special Latex notation for rotation matrices?

sin is one of the few "standard" functions, so it is recognized when we write \sin and will produce a nice roman font when inside an equation block.
If we try to do the same (\rotationMatrix) with non-standard functions, it will fail to output: we have to call mathrm explicitely. I don't think that there is a particular Latex syntax for rotations, so I assume we can live with the current version of math.parse('rotationMatrix(1)').toTex(), that produces a \mathrm.

A small example below:

\begin{equation}
  \begin{align*}
    \cos(\theta) \\
    cos(\theta) \\
    \rotationMatrix(\theta) \\
    rotationMatrix(\theta) \\
    \mathrm{rotationMatrix(\theta)}
  \end{align*}
\end{equation}

I don't think that there is a particular Latex syntax for rotations, so I assume we can live with the current version of

Thanks for the explanation, I agree, looks good like this 👍 . Thanks again, will merge your PR now.

Available now in v7.4.0, thanks again.