Change imaginary unit in siunitx

Question

Is there any way to change the default imaginary unit of siunitx to \mathrm j instead of \mathrm i?
Thanks.

Answer 1

The key output-complex-root defines that, and the default is

\ensuremath{\mathrm{i}}

Hence,

\sisetup{output-complex-root=\ensuremath{\mathrm{j}}}

should do what you want.

For input, you can use both i and j.

\documentclass[border=5mm]{standalone}
\usepackage{siunitx}
\sisetup{output-complex-root=\ensuremath{\mathrm{j}}}
\begin{document}
\num{1+2i} \num{1+2j}
\end{document}