11

Consider the following example.

Code

\documentclass{article}

\usepackage[per-mode=symbol-or-fraction]{siunitx}

\begin{document}
\[ \frac{x}{\SI{4}{\m\per\degree}} \]
\end{document}

Output

Output

Question

Why is the per-mode option set to symbol? Shouldn't it be fraction or am I missing something obvious?

1 Answer 1

10

See the difference bettween per-mode=fraction and per-mode=symbol.

\documentclass{article}

\usepackage{siunitx}
\begin{document}
\[ \frac{x}{\SI[per-mode=fraction]{4}{\m\per\degree}} \]
\[ \frac{x}{\SI[per-mode=symbol]{4}{\m\per\degree}} \]
\[ \textstyle \frac{x}{\SI[per-mode=symbol-or-fraction]{4}{\m\per\degree}} \]
\[ \displaystyle \frac{x}{\SI[per-mode=symbol-or-fraction]{4}{\m\per\degree}} \]
\[ \frac{x}{\SI[per-mode=symbol-or-fraction]{4}{\m\per\degree}} \]
\[ \frac{x}{\displaystyle\SI[per-mode=symbol-or-fraction]{4}{\m\per\degree}} \]
\end{document}

enter image description here

In fact, in the last two equations, \per should be printed as fraction, like the siunitx manual (bottom of p. 41) points out:

Setting per-mode to symbol-or-fraction will use the symbol setting for in line math, and the fraction setting when used in \displaystyle math.

There is probably a bug or an omission of some option.

4
  • 1
    How is it a bug? The denominator of a displaystyle fraction is in textstyle by default, just see the output of \frac{1}{\sum_{i=1}^{n}{a_i}}.
    – T. Verron
    Apr 29, 2013 at 5:30
  • @T.Verron Okay. I, as well, thought it was in \displaystyle math. Apr 29, 2013 at 5:49
  • 2
    I'd say this is a subtly that should probably go into the manual: @T.Verron is correct that \textstyle is active at the point of choice (and I'd say this looks 'best'), but that might not be obvious to most people.
    – Joseph Wright
    Apr 29, 2013 at 6:06
  • I edited my answer to add the \displaystyle in the denominator. As expected the visual result is not the same as using the per-mode=fraction.
    – cacamailg
    Apr 29, 2013 at 9:45

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.