how can I create q bar symbol in math mode just like \hbar?

Question

I need create a new math symbol a q with a bar just like command \hbar (h with a bar)

Thanks for your help, this is an example

\documentclass[]{article}
\usepackage{polyglossia}
\setmainlanguage{spanish}
\usepackage[dvipsnames,svgnames,x11names,]{xcolor}
\usepackage{graphicx}
\usepackage{amsmath,mathtools,calculator}
\usepackage{commath}
\usepackage{xfrac}
\usepackage{fancybox}
\usepackage{multicol}
\usepackage{nicefrac}% UNIDADES SI
\usepackage{units}% UNIDADES SI
\usepackage{pgf,tikz,tikz-3dplot}
\usepackage{pgfplots}
\usepackage[american]{circuitikz}
\usetikzlibrary{arrows,patterns}
\usetikzlibrary{decorations.text,bending}
\usepgfplotslibrary{fillbetween}
\usepgfplotslibrary{groupplots,polar} %
\usepgflibrary{arrows.meta}
\usetikzlibrary{arrows.meta}
\usetikzlibrary{decorations.markings}
\usetikzlibrary{decorations.text}
\usepgfplotslibrary{fillbetween}
\usepgfplotslibrary{groupplots,polar}
\usepackage{cancel}
\usepackage{wasysym}
\usepackage{txfonts}
\usepackage{smartdiagram}
\usepackage{siunitx}
\usepackage{fourier} % math font
\usepackage{fontspec}
%\defaultfontfeatures{Mapping=tex-text}
\setmainfont{Arial}
\begin{document}
This is the document
$\left(x+a\right)^2$, I need a $q$ command with bar
\end{document}

Well, go to this answer and just replace lambda with q. You might want to further fine tune the height to suit q. — AboAmmar, Oct 11 '20 at 01:08
Avoid commath; I don't see how units helps as you're loading siunitx. Your preamble is full of contradictory calls: why txfonts if you're later loading fourier? And are you sure that fourier math fonts are compatible with Arial as the main text font? — egreg, Oct 14 '20 at 21:47

egreg · Accepted Answer · 2020-10-14T22:31:46.267

1

It depends on the math font you're using.

With Computer Modern, taking the cue from https://tex.stackexchange.com/a/551356/4427, but also from the fact that the bar is at a different position, namely \mathchar '26, we can do

\documentclass{article}
\usepackage{amsmath}
\makeatletter
\newcommand{\addbar@}[2]{%
  \makebox[0pt][l]{%
    \raisebox{#1}[0pt][0pt]{%
      \kern#2
      $\m@th\mathchar'26$%
    }%
  }%
}
\DeclareRobustCommand{\qbar}{\text{\addbar@{-1.5ex}{0.01em}}q}
\makeatother
\begin{document}
Normal size $q\ne \qbar$ and subscript $X_{q}\ne X_{\qbar}$
\end{document}

For the fourier math fonts, the code should be modified, because they don't have the required bar in the expected place. I'll solve this by horizontally scaling a minus sign.

\documentclass{article}
\usepackage{amsmath}
\usepackage{fourier}
\usepackage{graphicx}
\makeatletter
\newcommand{\addbar@}[3]{%
  \makebox[0pt][l]{%
    \raisebox{#1}[0pt][0pt]{%
      \kern#2
      \scalebox{0.6}[1]{$\m@th-$}%
    }%
  }%
}
\DeclareRobustCommand{\qbar}{\text{\addbar@{-0.8ex}{0.2em}{1}}q}
\makeatother
\begin{document}
Normal size $q\ne \qbar$ and subscript $X_{q}\ne X_{\qbar}$
\end{document}

edited Oct 14 '20 at 22:31

answered Oct 11 '20 at 09:31

egreg

1,121,712

Thanks for the answer, Im using as math font fourier from fourier package and Im using LuaLatex too... – Alejandro Munoz Ossa Oct 11 '20 at 14:22
Yes, but How can I do this q when Im Using Fourier font in LuaLatex – Alejandro Munoz Ossa Oct 11 '20 at 14:24
1

@AlejandroMunozOssa I stated at the outset that this depends on the fonts. Please, add a minimal version of your document preamble, limited to the font setup. – egreg Oct 11 '20 at 16:14
I added a code like you told me, thanks for the help – Alejandro Munoz Ossa Oct 14 '20 at 20:04
@AlejandroMunozOssa I added the workaround. – egreg Oct 14 '20 at 22:31

how can I create q bar symbol in math mode just like \hbar?

1 Answers1