树的决定

Question

我尝试重现这棵决策树但遇到了一些问题。

我就是这么做的

\documentclass{article}
\usepackage{tikz,forest}
\usetikzlibrary{arrows.meta}
\tikzset{% common styles of tikz pictures elements
  treenode/.style = {shape=rectangle, rounded corners,
                     draw, align=center, 
                     minimum height=2ex, text depth=0.25ex,
                     top color=white, bottom color=blue!20},
  root/.style     = {treenode, font=\Large\rmfamily, bottom color=red!30},
  env/.style      = {treenode, font=\ttfamily\normalsize},
}
\begin{document}
\begin{tikzpicture}[% local settings for tree
            grow                     = right,
            sibling distance         = 6em,
            level distance           = 10em,
            edge from parent/.style  = {draw, -latex},
            every node/.append style = {font=\footnotesize},
            sloped
        ]
        \node [root] {}    
            child { node [env] {\(M\)}
                child { node [env] {\(T\)}
                    edge from parent node [below] {\(p(T|M) = \dots\)}}
                child { node [env] {\(A\)} %%%confondu avec
                    edge from parent node [above] {\(p(\overline{T}|M) = \dots\)}}
                edge from parent node [below] {\(p(M) = \dots\)}
            }
            child { node [env] {\(\overline{M}\)}
                child { node [env] {\(B\)} %%%ceci
                    edge from parent node [below] {\(p(T|\overline{M}) = \dots\)}}
                child { node [env] {\(\overline{T}\)}
                    edge from parent node [above] {\(p(\overline{T}|\overline{M}) = \dots\)}}
                edge from parent node [above] {\(p(\overline{M}) = \dots\)}
            };
        \end{tikzpicture}

\end{document}

结果如下：

A 和 B 在同一个地方。

Answer 1

使用起来稍微容易一些forest（您已加载但未使用）。您可以使用它forestset来设置边缘标签的样式。

\documentclass{article}

\usepackage{forest}
\usetikzlibrary{arrows.meta}
\tikzset{% common styles of tikz pictures elements
  treenode/.style = {shape=rectangle, rounded corners,
                     draw, align=center, 
                     minimum height=2ex, text depth=0.25ex,
                     top color=white, bottom color=blue!20},
  root/.style     = {treenode, font=\Large\rmfamily, bottom color=red!30},
  env/.style      = {treenode, font=\ttfamily\normalsize}
}
\forestset{
  bedge/.style    = {edge label={node[midway, sloped, font=\footnotesize, below]{$#1$}}},
  aedge/.style    = {edge label={node[midway, sloped, font=\footnotesize, above]{$#1$}}}
}

\begin{document}

\begin{forest}
for tree={
    l sep=10em, s sep=6em,
    edge={-latex},
    math content,
    grow'=0, 
    if level=0{root}{env}
}
[, 
    [\overline{M}, aedge={p(\overline{M})=\cdots}
        [\overline{T}, aedge={p(\overline{T}|\overline{M})=\cdots}]
        [A, bedge={p(T|\overline{M})=\cdots}]
    ]
    [M, bedge={p(M)=\cdots}
        [B, aedge={p(\overline{T}|M)=\cdots}]
        [T, bedge={p(T|M)=\cdots}]
    ]
]
\end{forest}

\end{document}