这是原代码和图片:
\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}
如果我使用 \textbf{} 来加粗文本,代码和图像如下所示:
\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}
这里有三个问题,第一个减号变短了,而且整体不在圆心,而是在上方位置,第二个减号圆变小了,但是加号圆大小没变,第三个我想让减号比现在粗一点,怎么做?