Tikz 定位 \draw 不起作用

Question

我遇到了以下问题：我向路径添加了一个节点（使用 \draw 绘制），我希望该节点位于“中间”或“pos=.5”，但在以下示例中，该节点位于图形的第一个节点（rrhp）上，而不是圆弧上。我使用相同的加载库进行了其他绘图，定位成功，所以我想知道下面的代码有什么问题。

包含许多其他软件包，但它们似乎与 tikz 没有冲突，我包含了 pgfplots，尽管消除它并不能解决问题。

\documentclass{article}

\usepackage{tikz}
\usetikzlibrary{shadows,arrows,calc,backgrounds,fit,shapes,snakes,shapes.multipart,decorations.pathreplacing,shapes.misc,patterns,positioning}
\usepackage{pgfplots}

\begin{document}
\begin{tikzpicture}[node distance=4mm]
    \node[align=center] (rrhp) { Robust Relational \\ Hyperproperty Preservation};
    \node[align=center, below = of rrhp.south east] (r2rsp) { Robust 2-Relational \\ Safety Preservation};
    \node[align=center, below = of r2rsp.south, yshift=-3em] (fac2) { Fully Abstract\\ Compilation };

    \draw[-] (rrhp.south) to (r2rsp.north west);
    \draw[-, dotted] (r2rsp.south) to (fac2.north) node [right,align=left,pos=.5] { + determinacy } ;  

\end{tikzpicture}
\end{document}

Answer 1

使用 Line-To operation(< 坐标 > -- < 坐标 >) 代替To-Path operation(< 坐标 > 到 < 坐标 >) 就足够了：

\documentclass{article}

\usepackage{tikz}
\usetikzlibrary{shadows,arrows,calc,backgrounds,fit,shapes,snakes,shapes.multipart,decorations.pathreplacing,shapes.misc,patterns,positioning}
\usepackage{pgfplots}

\begin{document}
\begin{tikzpicture}[node distance=4mm]
    \node[align=center] (rrhp) { Robust Relational \\ Hyperproperty Preservation};
    \node[align=center, below = of rrhp.south east] (r2rsp) { Robust 2-Relational \\ Safety Preservation};
    \node[align=center, below = of r2rsp.south, yshift=-3em] (fac2) { Fully Abstract\\ Compilation };

    \draw[-] (rrhp.south) to (r2rsp.north west);
    \draw[-, dotted] (r2rsp.south) -- (fac2.north) node [right,align=left,pos=.5] { + determinacy } ;  

\end{tikzpicture}
\end{document}

第二种解决方案： 您使用的语法 To-Path operation与手册不匹配（3.0.1.a 手册第 157 页）

 \path ... to[options] < nodes > < coordinate or cycle > ...;

代码如下

\documentclass{article}

\usepackage{tikz}
\usetikzlibrary{shadows,arrows,calc,backgrounds,fit,shapes,snakes,shapes.multipart,decorations.pathreplacing,shapes.misc,patterns,positioning}
\usepackage{pgfplots}

\begin{document}
\begin{tikzpicture}[node distance=4mm]
    \node[align=center] (rrhp) { Robust Relational \\ Hyperproperty Preservation};
    \node[align=center, below = of rrhp.south east] (r2rsp) { Robust 2-Relational \\ Safety Preservation};
    \node[align=center, below = of r2rsp.south, yshift=-3em] (fac2) { Fully Abstract\\ Compilation };

    \draw[-] (rrhp.south) to (r2rsp.north west);
    \draw[-, dotted] (r2rsp.south) to  node [right,align=left,pos=.5] { + determinacy } (fac2.north);  

\end{tikzpicture}
\end{document}

Answer 2

我将使用quotes库并用它稍微简化图片代码：

\documentclass{article}
\usepackage{pgfplots} % <--- it load `tikz`
\usetikzlibrary{arrows,
                backgrounds,
                decorations.pathreplacing,
                calc,
                fit,
                patterns, positioning,
                quotes, % <--- added
                shadows, shapes, shapes.multipart, shapes.misc, snakes
                }

\begin{document}
\begin{tikzpicture}[node distance=4mm, align=center]
    \node (rrhp) { Robust Relational \\ Hyperproperty Preservation};
    \node [below=of rrhp.south east] (r2rsp) { Robust 2-Relational \\ Safety Preservation};
    \node[below=12mm of r2rsp] (fac2) { Fully Abstract\\ Compilation };
%
    \draw (rrhp.south) -- (r2rsp.north west);          % <--- changed
    \draw[dotted] (r2rsp) to ["+ determinacy"] (fac2); % <--- changed
\end{tikzpicture}
\end{document}