How to make the text in a node bold without changing the node and text size？

Question

This is the original code and picture：

\documentclass[tikz,border=2pt]{standalone} 
\usepackage{amsmath}
\usepackage{tikz}
\usepackage{xparse}
\usetikzlibrary{positioning}
\tikzset{
    basenode/.style = {
        circle,
        draw,
        inner sep=0pt,
        minimum size=3.5mm,
    },
    rednode/.style = { 
        basenode,
        fill=white,
        text = red,
    },
    bluenode/.style = { 
        basenode,
        fill=white,
        text = blue,
    },
}
\begin{document}
\NewDocumentCommand{\drawchargepair}{ r() r() }{
    % draws two connected charges
    % (#1) position of - charge
    % (#2) relative position of + charge
    \draw (#1) node[bluenode]{${-}$} -- ++(#2) node[rednode]{${+}$};
}
\begin{tikzpicture}[x={(10cm,0)},y={(0,1cm)}]
    \drawchargepair (0,0) (2cm, 0)
\end{tikzpicture}
\end{document}

If I use \textbf{} to bold the text, the code and image look like this:

\documentclass[tikz,border=2pt]{standalone} 
\usepackage{amsmath}
\usepackage{tikz}
\usepackage{xparse}
\usetikzlibrary{positioning}
\tikzset{
    basenode/.style = {
        circle,
        draw,
        inner sep=0pt,
        minimum size=3.5mm,
    },
    rednode/.style = { 
        basenode,
        fill=white,
        text = red,
    },
    bluenode/.style = { 
        basenode,
        fill=white,
        text = blue,
    },
}
\begin{document}
\NewDocumentCommand{\drawchargepair}{ r() r() }{
    % draws two connected charges
    % (#1) position of - charge
    % (#2) relative position of + charge
    \draw (#1) node[bluenode]{$\textbf{-}$} -- ++(#2) node[rednode]{$\textbf{+}$};
}
\begin{tikzpicture}[x={(10cm,0)},y={(0,1cm)}]
    \drawchargepair (0,0) (2cm, 0)
\end{tikzpicture}
\end{document}

There are three problems here. The first minus sign has become shorter, and the whole is not in the center of the circle, but in the upper position. The second minus sign circle has become smaller, but the size of the plus sign circle has not changed. Third, I want to make the sign thicker than it is now, how should I do it?

@Qrrbrbirlbel I have used it, it may or may not be bold, because my naked eye can't tell it at all, and I hope it is a lot bolder, at least the naked eye can tell — Zhao Dazhuang, Oct 20 '22 at 07:43
Would be duplicate of math mode - Thicker line for minus sign and plus sign - TeX - LaTeX Stack Exchange if that's thick enough for you. Otherwise... — user202729, Oct 20 '22 at 09:53
Or A bold plus symbol in math mode - TeX - LaTeX Stack Exchange etc. — user202729, Oct 20 '22 at 09:54
@ZhaoDazhuang That's a font issue then and has nothing to do with TikZ and nodes. (See the other links by @us3r202729.) With \textbf you switched back to text mode and the - became a hyphen again. Obviously, you could just draw the - and + with TikZ (and not as text), too. — Qrrbrbirlbel, Oct 20 '22 at 09:58

How to make the text in a node bold without changing the node and text size？

0 Answers0