TikZ 因果图详细信息（粗体、箭头位置、路径上方的文本）

Question

我很难弄清楚如何使用 TikZ 设计因果图。该图应如下所示：

下面的代码是我所能得到的，但它没有一些重要的细节（见图）。首先，如何在路径顶部添加文本（红色）？我见过使用 \draw 的示例，其中 {text} 就足够了，但如果我将其添加到我的图表中，它就不再编译了。其次，如何添加粗体文本和换行符？第三，理想情况下，箭头应该在节点之前/之后开始和结束，就像在图中一样，而不是在节点的中心（X 到 Z 和 Z 到 Y）。

\documentclass[10pt]{article}
\usepackage{color}
\usepackage{tikz}

\usetikzlibrary{shapes,decorations,arrows,calc,arrows.meta,fit,positioning}
\tikzset{
    -Latex,auto,node distance =1 cm and 1 cm,semithick,
    state/.style ={ellipse, draw, minimum width = 0.7 cm},
    point/.style = {circle, draw, inner sep=0.04cm,fill,node contents={}},
    bidirected/.style={Latex-Latex,dashed},
    el/.style = {inner sep=2pt, align=left, sloped}
}
\begin{document}

\begin{tikzpicture}
\begin{tikzpicture}
\usetikzlibrary{positioning}

    \node (1) at (6,0) {Some \ Text \ for \ X};
    \node (2) [right = 7cm of 1] {Some \ Text \ for \ Y};
    \node (3) [above right = 3cm of 1] {Some \ Text \ for \ Z};
    \node (t1) [above = 0.6cm of 3] {Text bold (with line break)};

    \draw (1) -- (2);
    \draw (3) -- (2) [anchor=west];
    \draw (1) -- (3);
    
    \node (4) at (6,6) {Some \ Text \ for \ X};
    \node (5) [right = 7cm of 4] {Some \ Text \ for \ Y};
    \node (6) [above right = 3cm of 4] {Some \ Text \ for \ Z};
    \node (t2) [above = 0.6cm of 6] {Text bold (with line break)};


    \draw (4) --  (5);
    \draw (6) -- (5);
    \draw (4) -- (6);
    
    
    \node (7) at (6,12) {Some \ Text \ for \ X};
    \node (8) [right = 7cm of 7] {Some \ Text \ for \ Y};
    \node (9) [above right = 3cm of 7] {Some \ Text \ for \ Z};
    \node (t2) [above = 0.6cm of 9] {Text bold (with line break)};


    \draw (7) --  (8);
    \draw (9) -- (8);
    \draw (7) -- (9);
\end{tikzpicture}

\end{tikzpicture}
\end{document} 

Answer 1

让我们来看看：

• 要有多行节点，你必须指定一个align键；要自动换行，你需要一个text width
• 要更改节点的字体，您可以使用键font
• 要在路径周围添加文本，您只需将其放在node路径中间即可。默认情况下，它是水平的并且位于中间，但您可以使用sloped和pos键进行更改。

示例（这是最小的，并且没有嵌套tikzpicture......）

\documentclass[10pt]{article}
\usepackage{color}
\usepackage{tikz}

\usetikzlibrary{shapes,decorations,arrows,calc,arrows.meta,fit,positioning}
\tikzset{
    -Latex,auto,node distance =1 cm and 1 cm,semithick,
    state/.style ={ellipse, draw, minimum width = 0.7 cm},
    point/.style = {circle, draw, inner sep=0.04cm,fill,node contents={}},
    bidirected/.style={Latex-Latex,dashed},
    el/.style = {inner sep=2pt, align=left, sloped}
}
\begin{document}

\begin{tikzpicture}

    \node (1) at (6,0) {Some \ Text \ for \ X};
    \node (2) [right = 7cm of 1] {Some \ Text \ for \ Y};
    \node (3) [above right = 3cm of 1] {Some \ Text \ for \ Z};
    \node (t1) [above = 0.6cm of 3, text width=4cm, align=center, font=\bfseries] {Text bold (with line break)};
    \draw (1) -- node[red, above ]{text in red} (2);
    \draw (3) -- node [red, above , sloped] {text in red, sloped} (2) [anchor=west];
    \draw (1) -- node [red, above left, pos=0.2, align=center] {text in red,\\ horizontal at 0.2} (3);
\end{tikzpicture}
\end{document}

然后有几个库可以简化这类图表的输入；一个很好的起点是Ti 中的第二个教程钾Z 手册。

Answer 2

作为交换图：

\documentclass[border?3.141592]{article}
\usepackage{amsmath}
\usepackage{makecell}
\usepackage{tikz-cd}
\tikzcdset{
arrow style = tikz,
     arrows = {>=Straight Barb, semithick},
     % nodes = {align=center}
            }
\begin{document}
    \begin{tikzcd}%[ampersand replacement=\&]
   &   \textbf{\makecell{Text bold\\ (with line break)}}
        &   \\
   &   \text{Some Text for Z}  \ar[rd, "\beta"]
        &   \\
\text{Some Text   for X}   \ar[ur, "\alpha"] \ar[rr, "\gamma" ']
    &   &   \text{Some Text for Y}
    \end{tikzcd}
\end{document}