☰

使用森林包的树形图-箭头的位置

tag-icon • tag-icon forest
使用森林包的树形图-箭头的位置

我是 latex 包的新手forest。如何在 中实现预期结果LaTeX。如何arrows在 forest 包中移动？

我的 MWE 是：

\documentclass{beamer}
\usepackage{qtree}
\usepackage[linguistics]{forest}
\useforestlibrary{linguistics}
\usetikzlibrary{shapes.geometric}
\usepackage{mathptm}

\forestset{
 sn edges/.style={for tree={parent anchor=south, child anchor=north}},
        background tree/.style={for tree={
            text opacity=0.8,draw opacity=0.8,edge={draw opacity=0.8}}}
}

\begin{document}
\centering
\begin{forest}
    [\textrm{CP},
        [\phantom{xxxxxxxxxxxxxxxxxxxx}\v{\!\!\!\d{c}}\hbox{'}al-$\textrm{ew}_{\textrm{i}}$\phantom{xxxxxxxxxxxxxxxxxxxx},name=spec CP]
            [$\textrm{C}^\prime$
                [\phantom{xxxxxxx}TP\phantom{xxxxxxx}
                    [\phantom{xxxxxxx}vP\phantom{xxxxxxx}
                        [\phantom{xxxxxxx}DP\phantom{xxxxxxx}
                            [$\textrm{Op}_{\textrm{i}}$,name=spec PC]
                            [PossP
                                [\!\!\!$_{-\!\!\!-\!\!\!-\!\!\!-\!\!\!-}{_{\textrm{PG}}}$ z-\v{s}, name=objects, roof]]]
                        [$\textrm{v}^\prime$
                            [\!\!\!$t_i({{\scriptstyle{\textrm{IO}}}}) \emptyset${-ze-r-j-t}, name=object, roof]]]
                    [T[-e]]]
                    [C${[{\scriptstyle{\textrm{WH}}}]}$]
            ]
    ]
    \draw[->] (object) to[out=south west,in=south] (spec CP);
    \draw[->] (objects) to[out=south west,in=south] (spec PC);
\end{forest}

\end{document}

预期结果是在此处输入图片描述

答案1

严格来说，绘制箭头是 TikZ 的事情，即使是在森林树中绘制也是如此。我想这是一门艺术——PGF/TikZ 手册的第 13 章和第 15 章是这里的终极参考来源，该手册中的教程也应该会很有帮助。

继续讨论森林业务，有两个技巧必须使用才能得到所需的树。第一个很简单：“fit=band”将创建一个下面没有任何内容的节点；当嵌入“for tree”时，如下所示，我们得到一个“宽”树。（因此，“for tree={fit=band}”消除了对 OP 的幻象“xxx”的需求。）

第二个技巧很复杂。我们如何让外箭头在绕 DP 子树一圈后笔直向上射出？如果我们对此不做任何处理，它会稍微向左射出，因为“č'al-ew_i”向左移动太多——请记住，“fit=band”的效果是将节点下方的空间留空。这里的想法是使用空节点排版树——下面，我另外删除了 (i) 该节点的内部 x 空间和 (ii) 节点与其兄弟节点之间的“s 分隔”——然后才放入所需的内容。要了解如何绘制箭头本身，请查看（注释的）代码。

我还擅自清理了代码。我删除了\textsubscript用于文本模式下标的多余的包、用于语音符号的包\textipa（来自包）和用于功能的包（小写字母）。tipa\textsc

\documentclass{beamer}
\usepackage[linguistics]{forest}
\usepackage{tipa}

\begin{document}
\centering
\begin{forest}
  for tree={
    plain content, % The linguistics library default has a little bug which results in some undesired space below each node. (The culprit is "align=center" in "default preamble".) Key "plain content" reverses that, but note that it only allows for single-line nodes.
    fit=band, % Removing this will result in a more compact tree.
  },
  [CP,
    [% \d{\v{c}}'al-ew\textsubscript{i},
      % We don't set the content of the node right away (it is commented out above), but rather pack the tree with this node empty --- which results in the center of "č'al-ew_i" being right above the west of Op_i --- and swap the empty node for the real node only just before drawing the tree.
      ,inner xsep=0, for parent={s sep=0}, before drawing tree={content=\d{\v{c}}'al-ew\textsubscript{i}, typeset node},
      name=spec CP,
      fit=band, % Strictly speaking, this is not necessary, it is only here so that if we remove the upper "fit=band", the arrow to spec-CP still shoots straight up.
    ]
    [C$^\prime$
      [TP
        [vP
          [DP
            [Op\textsubscript{i},name=Op] % text mode subscript
            [PossP
              [\textsubscript{\text{------PG}} \textipa{z@-\v{s}}, inner xsep=0, roof]
              % "---" = em dash
              {\draw[->] () to[out=south west,in=south] (Op);}
            ]
          ]
          [v$^\prime$
            [$t$\textsubscript{i}(\textsc{io}) $\emptyset$\textipa{-ze-r-j@-t@}, roof, inner xsep=0]
            {\draw[->,overlay]
              (.south west) % start at the bottom left of the node
              +(1.2em,0pt) % move a bit to the right, without drawing a line
              to[out=south,in=south,looseness=2]
              (Op.west) % loop to the west of Op_i, loosely ("looseness" sets two parameters, "in looseness" and "out looseness")
              -- (spec CP);}
          ]
        ]
        [T[\textipa{-Ke}]] % IPA
      ]
      [{C[\textsc{wh}]}] % small caps
    ]
  ]
\end{forest}

\end{document}

相关内容