我正在尝试绘制史密斯图，它也具有负阻抗。这是我到目前为止所取得的进展：
\documentclass[]{standalone}
\usepackage{tikz}
\usepackage{pgfplots}
\usetikzlibrary{pgfplots.smithchart}
\makeatletter
\begin{document}
\begin{tikzpicture}
\begin{smithchart}[
yticklabel around circle,
show origin,
xtick={-0.3,-0.2,-0.1,0.1,0.2,0.3,0.4,0.5,1,1.5,2,3,4,5,10,20,-20,-10,-5,-4,-3},
]
\addplot[mark=none,line width=2]
coordinates{
(1, 0) (1, 0.1) (1,0.2) (1,0.3) (1,0.4) (1,0.5) (1,0.5)
};
\end{smithchart}
\end{tikzpicture}
\end{document}
结果不太令人满意，当 x 值开始变为负值时，y 轴的圆圈就停止了：
目标看起来与此类似，但如果 y 轴能够延续，我会很高兴：)
编辑：所以我做了同样的进展。首先，我可以移动标记 x 轴的外圆：
\documentclass[preview]{standalone}
\usepackage{tikz}
\usepackage{pgfplots}
\usetikzlibrary{pgfplots.smithchart}
\makeatletter
\begin{document}
\begin{tikzpicture}
\begin{smithchart}[
yticklabel around circle,
show origin,
xtick={-0.3,-0.2,-0.1,0.1,0.2,0.3,0.4,0.5,1,1.5,2,3,4,5,10,20,-20,-10,-5,-4,-3},
xmin=-0.3, %works quite well
xmax=-3, %xmax seems to be always infinty?!?!?
ticklabel style={opacity=0.5},
]
\addplot[mark=none,line width=2]
coordinates{
(1, 0) (1, 0.1) (1,0.2) (1,0.3) (1,0.4) (1,0.5) (1,0.5)
};
\end{smithchart}
\end{tikzpicture}
\end{document}
结果看起来像这样，这并不令人满意，因为 xmax 被忽略（总是接近无穷大）并且只能在旧的、小的（正 x）圆内绘制线条：
接下来的事情，当 x 为负时绘制 y 圆，似乎在某种程度上也是可行的。
...... %just as before
\begin{smithchart}[
yticklabel around circle,
show origin,
xtick={-0.3,-0.2,-0.1,0.1,0.2,0.3,0.4,0.5,1,1.5,2,3,4,5,10,20,-20,-10,-5,-4,-3},
ygrid each nth passes x={-3},
ticklabel style={opacity=0.5},
]
\addplot[mark=none,line width=2]
coordinates{
(1, 0) (1, 0.1) (1,0.2) (1,0.3) (1,0.4) (1,0.5) (1,0.5)
};
\end{smithchart}
.....
结果如下：
再次编辑：通过叠加两个史密斯图，它再次更接近所需的外观......但不能画出 x 为负的线！
\documentclass[preview]{standalone}
\usepackage{tikz}
\usepackage{pgfplots}
\usetikzlibrary{pgfplots.smithchart}
\makeatletter
\begin{document}
\begin{tikzpicture}
\begin{smithchart}[
show origin,
xtick={-0.3,-0.2,-0.1,0.1,0.2,0.3,0.4,0.5,1,1.5,2,3,4,5,10,20,-20,-10,-5,-4,-3},
ygrid stop at x={0.2:-.3,-0.2:-.3, 0.5:-.3,-0.5:-.3, 1:-.3,-1:-.3, 2:-3,-2:-2.99, 5:-6,-5:-5.99,},
xmin=-0.3, %works quite well
%xmax=-3, %xmax seems to be alwys infinty?!?!?
ticklabel style={white,opacity=0},
]
\end{smithchart}
\begin{smithchart}[
show origin,
xtick={-0.3,-0.2,-0.1,0.1,0.2,0.3,0.4,0.5,1,1.5,2,3,4,5,10,20,-20,-10,-5,-4,-3},
ygrid stop at x={0.2:-3,-0.2:-3,0.5:-3,-0.5:-3,1:-3,-1:-3, 2:-3.01,-2:-3.0, 5:-6.01,-5:-6.0,},
xmin=-0.3, %works quite well
%xmax=-3, %xmax seems to be alwys infinty?!?!?
ticklabel style={opacity=0},
]
\addplot[mark=none,line width=2]
coordinates{
(1, 0) (1, 0.1) (1,0.2) (1,0.3) (1,0.4) (1,0.5) (1,0.5)
};
\addplot[mark=none,line width=0.5]
coordinates{
(1, 0) (-0.3, 0) % this one is not drawn outside!!!
};
\end{smithchart}
\end{tikzpicture}
\end{document}
答案1
您想要的更多是对该库的功能请求（该库无法处理那种图形）。
不过，我可以帮助您完成一项简单的任务：添加clip=false抑制\addplot操作剪辑——这将绘制您的自定义轴。
绘制不完整的圆（y 网格）是由于pgfplots计算具有精确端点的圆弧 - 并且似乎仅限于正值。执行此操作的代码包含“这是正确的完整圆”之类的注释以及生成该圆的代码。请参阅\pgfplots@smithchart@draw@yarc。tikzlibrarypgfplots.smithchart.code.tex如果您修补该宏（包括未注释的内容\pgfpathellipse而不是其后的内容），则可以获得完整的 y 网格线圆。不过，您需要以某种方式处理剪辑路径。
答案2
所以我有一个解决方案，但不是很好。也许几个月后，当我有更多时间时，我会更深入地研究代码......
\documentclass[preview]{standalone}
\usepackage{tikz}
\usepackage{pgfplots}
\usetikzlibrary{pgfplots.smithchart}
\pgfplotsset{
axis line style={opacity=1},
every axis label/.append style ={white,opacity=0},
every tick label/.append style={white,opacity=0}
}
\makeatletter
\begin{document}
\begin{tikzpicture}
\begin{smithchart}[
yticklabel around circle,
show origin,
clip=false,
xtick={-0.2,-0.1,0.1,0.2,0.3,0.4,0.5,1,1.5,2,3,4,5,10,20,-20,-10,-5,-4},
ygrid stop at x={0.2:-.3,-0.2:-.3, 0.5:-.365,-0.5:-.365, 1:-.63,-1:-.63, 2:-3,-2:-2.99, 5:-6,-5:-5.99,},
]
\addplot[mark=none,line width=0.4,]
coordinates{
(-3.5, 0) (-0.285, 0)
};
\draw[black!30] (1,0) arc (-180:-61:0.5) ;
\draw[black!30] (1,0) arc (180:61:0.5) ;
\draw[black!30] (1,0) arc (-180:-116:1) ;
\draw[black!30] (1,0) arc (180:116:1) ;
\draw[black!30] (1,0) arc (0:-145:1.43) ;
\draw[black!30] (1,0) arc (0:145:1.43) ;
\draw[black!30] (1,0) arc (0:-64:2) ;
\draw[black!30] (1,0) arc (0:64:2) ;
\draw[black!30] (1,0) -- (1,1.5) ;
\draw[black!30] (1,0) -- (1,-1.5) ;
\draw[mark=none,line width=0.5,]
circle[radius=1.8]{};
\end{smithchart}
\begin{smithchart}[
clip=false,
yticklabel around circle,
show origin,
xtick={-0.2,-0.1,0.1,0.2,0.3,0.4,0.5,1,1.5,2,3,4,5,10,20,-20,-10,-5,-4},
ygrid stop at x={0.2:-3.5,-0.2:-3.5,0.5:-3.45,-0.5:-3.45, 1:-3.15,-1:-3.15, 2:-3.01,-2:-3.0, 5:-6.01,-5:-6.0,},
ticklabel style={opacity=0},
]
\addplot[mark=none,line width=2]
coordinates{
(1, 0) (1, 0.1) (1,0.2) (1,0.3) (1,0.4) (1,0.5) (1,0.5)
};
\end{smithchart}
\end{tikzpicture}
\end{document}
结果并不像我开始所提出的图片那么好，但至少它是错误的。
