How to put a curvearrow around a letter?

Question

In physics, it's sometimes useful to draw an arrow over a letter to represent the torch around that point. I've seen this in multiple textbooks and would like to know how to do it myself in \LaTeX documents. Anyone who knows a solution for this?

Note that this isn't just about putting a \curverarrow above a letter, but surrounding the letter by the curved arrow like in the picture I attached below.

Thanks in advance for the help and have a good day :)

score 11 · Answer 1 · answered Mar 15 '21 at 11:54

11

You could use \curvearrowleft from AMS Symbols, e.g.:

\documentclass{article}
\usepackage{amssymb}
\newcommand{\curvearrow}[1]{\ooalign{\kern1pt \ensuremath{#1}\cr\hidewidth\raise.8ex\hbox{$\curvearrowleft$}\hidewidth}}
\begin{document}
$\curvearrow{a}, \curvearrow{b}, \curvearrow{c}$
\end{document}

Perhaps you have to tweak the distances, e.g. to cover capital letters.

answered Mar 15 '21 at 11:54

Matthias

711

I like the simplicity here, keeping the \usepackage count low. It doesn't match the exact look but certainly solves the crux of the problem :) – StiggyStardust Mar 17 '21 at 17:35

score 7 · Answer 2 · edited Mar 15 '21 at 19:27

7

Something like this, with the \nccircle command from pst-node?

\documentclass[12pt]{article}
\usepackage{pst-node}
\begin{document}
\psset{arrowinset=0.1}
$\psDefBoxNodes{A}{A}\nccircle[nodesep =5pt]{-&gt;}{A:bC}{0.6em}$%


\end{document}

edited Mar 15 '21 at 19:27

Vincent

20,157

answered Mar 15 '21 at 11:52

Bernard

271,350

Very nice use of pst-node indeed. Putting this within a \newcommand and this would be a very easy method to implement. – StiggyStardust Mar 17 '21 at 17:39

score 7 · Answer 3 · answered Mar 15 '21 at 12:12

7

Not sure if this looks too appealing but maybe this goes in the right direction.

\documentclass{article}
\usepackage{mathtools}
\usepackage{amssymb}
\usepackage{scalerel}
\newcommand\OverCurveArrowRight[2][n]{%
\setbox0\hbox{\scalerel*{\curvearrowright}{\overset{#1}{#2}}}\copy0%
\mathllap{\mathmakebox[\wd0]{#2\hskip0.2\wd0}}}
\newcommand\OverCurveArrowLeft[2][n]{%
\setbox0\hbox{\scalerel*{\curvearrowleft}{\overset{#1}{#2}}}\copy0%
\mathllap{\mathmakebox[\wd0]{\hskip0.2\wd0#2}}}
\begin{document}
abc $\OverCurveArrowRight{A}$ $\OverCurveArrowLeft{A}$ 
\[\OverCurveArrowRight{A}\to\OverCurveArrowLeft{A}\]
\[\OverCurveArrowRight[\int]{\int}\to\OverCurveArrowLeft{A}\]
\end{document}

answered Mar 15 '21 at 12:12

I like very much your approach. – Sebastiano Mar 15 '21 at 20:54
Some of them seem to go in the left direction, though. – Pål GD Mar 15 '21 at 21:22
@PålGD You have to look at those from the back. – Mar 15 '21 at 21:40
This is very good in the output, and if the looks are a priority I would pick this because it's open for quality customization. :) – StiggyStardust Mar 17 '21 at 17:38

score 6 · Answer 4 · answered Mar 15 '21 at 21:39

Starting from the code of the answer of the user @egreg in this question How to write a character overlapping another character I have adapted this using the packages graphicx, scalerel to have a little big arrow and to rotate the symbol \circlearrowleft of 170 degrees (for example).

\documentclass[a4paper,12pt]{article}
\usepackage{newtxtext,newtxmath}
\usepackage{graphicx,scalerel}
\makeatletter
\DeclareRobustCommand{\as}[1]{
  {\vphantom{#1}\mathpalette\erel@as{#1}}%
}
\newcommand{\cla}{\rotatebox[origin=c]{170}{\hstretch{1}{$\scaleobj{1.5}{\circlearrowleft}$}}}
\newcommand{\erel@as}[2]{%
  \ooalign{\hfil$\m@th#1\cla$\hfil\cr\hfil$\m@th#1#2$\hfil\cr}%
}
\makeatother
\begin{document}
$\as{A}$
\end{document}

Thanks for linking to the how to overlap a character, together with your example that's very good for understanding. — StiggyStardust, Mar 17 '21 at 17:40

How to put a curvearrow around a letter?

4 Answers4