A problem in creating symbols by TikZ

Question

First, a minimal working sample is as follows.

\documentclass{article}
\usepackage{tikz}
\makeatletter
\newcommand*\newcirc{\mathrel{%
\tikz{%
\draw (0em,0em) circle [radius=0.2em];%
}}}
\makeatother
\begin{document}
[
\phi\newcirc\psi
]
\end{document}

As you see, I defined a math symbol of \newcirc by TikZ. It seems to work well. While when I put it in the script without brackets, for example, $\phi_\newcirc$ , it doesn't work. So is there any way to fix the problem by revising the codes? (I don't like to add brackets every time when I use it singly in the script, for example, $\phi_{\newcirc}$ )

If you add more than one character to the subscript, you have to use curly brackets. So $\phi_{\newcirc}$ is correct. But you can put \bgroup and \egroup (or a pair of curly brackets) intro the command to make it work for the command. — dexteritas, Sep 08 '23 at 08:32
See Why do I have to put braces around my macro for subscripts / indices? - TeX - LaTeX Stack Exchange and related questions. — user202729, Sep 08 '23 at 08:52
@dexteritas While in this way, the spacing around the symbol would change. — M. Logic, Sep 08 '23 at 09:07
Ok, yes, if you put brackets around \mathrel the spacing usually added by this is ignored, so $\phi_{\newcirc}$ would be the best way, to not change the behavior in the other case. — dexteritas, Sep 08 '23 at 09:24
I agree that the correct way is to get used to use _{...} (which is the correct, LaTeX syntax anyway). You can get a look at https://tex.stackexchange.com/a/571062/38080 for a way to make the symbols scale. — Rmano, Sep 08 '23 at 09:35
Not an answer to your question, but your symbol will not scale down when used in a subscript. You might consider the scalerel package and the definition \newcommand{\newcirc}{\mathrel{\scalerel*{\tikz{\draw circle [radius=0.2em];}}{x}}}. — Sandy G, Sep 08 '23 at 17:46

minorChaos · Answer 1 · 2023-09-08T15:06:35.827

0

I don't like to add brackets every time when I use it singly in the script, for example, $\phi_{\newcirc}$

You may define a command which frees you from typing _{ }:

\newcommand{\phiI}[1]{\phi_{#1}}
\phiI\newcirc

which works as long as you your intention i to put just one token after \phiI.

(It is good idea to combine that with scaled definition of \newcirc as Rmano suggests.)

You could define _ to make it behave the same as \ind I define bellow, but I do not think redefining _ is a good idea.

There are more ways how to save some typing:

\newcommand\phicirc{\phi_{\newcirc}}
\[ \phicirc \]
\newcommand\gr[1]{{#1}}
[ \phi_\gr\newcirc ]
\newcommand\grcirc{{\newcirc}}
[ \phi_\grcirc ]
\newcommand\ind[1]{_{#1}}
[ \phi\ind\newcirc ]
\newcommand\indcirc{_{\newcirc}}
[ \phi\indcirc ]
[ \psi\indcirc - \mu\indcirc]
\newcommand\withcirc[1]{#1_{\newcirc}}
[ \withcirc\psi + \withcirc\mu + \withcirc\phi  ]

Sometimes I use optional arguments, e.g.,

\renewcommand\phicirc[1][]{\phi_{\newcirc#1}}
\[ \phicirc  \qquad   \phicirc[_3]   \]

edited Sep 08 '23 at 15:06

answered Sep 08 '23 at 09:53

minorChaos

260
6

1

But we may use $\psi_{\newcirc}$ and so on. – M. Logic Sep 08 '23 at 13:09
You can use any choice of the suggestion. For example \mu\indcirc or define \mucirc analogically to \phicirc. Or we can define \withcirc -- I will added it to the answer. – minorChaos Sep 08 '23 at 14:15
It seems not to decrease the consumption of physical power validly. – M. Logic Sep 08 '23 at 16:44
1

@M.Logic Do you mean it doesn't reduce the typing? – cfr Sep 09 '23 at 01:31

A problem in creating symbols by TikZ

1 Answers1