使用森林包时尺寸太大-空节点太多？

Question

当我使用以下代码时

\documentclass{article}
\usepackage[edges]{forest}

\begin{document}
    
\begin{forest}
  for tree={
    grow'=east,
    anchor=west,
    font=\itshape,
    forked edge,
    fork sep = 2mm, 
    l sep=4mm,
    s sep=2mm,
  },
  s sep=2mm,
 delay={   where content={}{coordinate}{}, },
  [XXX-root,
   [ % 1
    [ % 2
     [XXX-children-A
      [XXX-children-B]
      [XXX-children-C]
     ] 
     [XXX-children-D]
    ]
    [ % 3
     [XXX-children-E]
     [XXX-children-F
      [XXX-children-G]
       [ % 4
        [XXX-children-H]
        [XXX-children-I]
       ]
     ]
    ]
   ]
   [ % 5
    [ % 6
     [XXX-children-J]
     [XXX-children-K]
    ]
    [ % 7
      [XXX-children-L]
      [XXX-children-M
        [XXX-children-N]
        [ % 8
         [XXX-children-O]
         [ % 9
          [XXX-children-P]
          [ % 10
          [ % 11
             [XXX-children-Q]
             [XXX-children-S]
         ]
         [ % 12
            [XXX-children-T]
            [XXX-children-U]
          ]
          ]
         ]
        ]
      ]
    ] 
   ]
  ]
\end{forest}
\end{document}

一切正常。但是，如果我在以下代码中更改节点中的文本

\documentclass{article}
\usepackage[edges]{forest}

\begin{document}
\begin{forest}
  for tree={
    grow'=east,
    anchor=west,
    font=\itshape,
    forked edge,
    fork sep = 2mm, 
    l sep=4mm,
    s sep=2mm,
  },
  s sep=2mm,
 delay={   where content={}{coordinate}{}, },
  [Nymphalidae,
   [ % 1
    [ % 2
     [Limenitidinae
      [Neptini]
      [Limenitidini]
     ]
     [Heliconiinae]
    ]
    [ % 3
     [Apaturinae]
     [Nymphalinae
      [Nymphalini]
       [ % 4
        [Junoniini]
        [Melitaeini]
       ]
     ]
    ]
   ]
   [ % 5
    [ % 6
     [Libytheinae]
     [Danainae]
    ]
    [ % 7
      [Charaxinae]
      [Satyrinae
        [Elymniini]
        [ % 8
         [Coenonymphini]
         [ % 9
          [Ypthimini]
          [ % 10
          [ % 11
             [Melanargiini]
             [Satyrini]
         ]
         [ % 12
            [Maniolini]
            [Erebiini]
          ]
          ]
         ]
        ]
      ]
    ]
   ]
  ]
\end{forest}

\end{document}

我收到错误消息！尺寸太大。\pgf@x

如果我将空节点 11 和 12 更改为包含一个或多个字符的节点，则一切正常。这非常令人困惑，因为两段代码之间的唯一区别是每个节点中的文本。

Answer 1

我不知道为什么会出现这个错误。但是，使用坐标的目的似乎是为了避免间隙。这里有一个也可以避免间隙的解决方法：用一些短的水平线段替换空节点。

\documentclass{article}
\usepackage[edges]{forest}

\begin{document}
\begin{forest}
  for tree={
    grow'=east,
    anchor=west,
    font=\itshape,
    forked edge,
    fork sep = 2mm, 
    l sep=4mm,
    s sep=2mm,
  },
  s sep=2mm,
 delay={   where content={}{outer sep=0pt,inner sep=0pt,
    append after command={(\tikzlastnode.west) edge (\tikzlastnode.east)}}{}, },
  [Nymphalidae,
   [ % 1
    [ % 2
     [Limenitidinae
      [Neptini]
      [Limenitidini]
     ]
     [Heliconiinae]
    ]
    [ % 3
     [Apaturinae]
     [Nymphalinae
      [Nymphalini]
       [ % 4
        [Junoniini]
        [Melitaeini]
       ]
     ]
    ]
   ]
   [ % 5
    [ % 6
     [Libytheinae]
     [Danainae]
    ]
    [ % 7
      [Charaxinae]
      [Satyrinae
        [Elymniini]
        [ % 8
         [Coenonymphini]
         [ % 9
          [Ypthimini]
          [ % 10
          [ % 11
             [Melanargiini]
             [Satyrini]
         ]
         [ % 12
            [Maniolini]
            [Erebiini]
          ]
          ]
         ]
        ]
      ]
    ]
   ]
  ]
\end{forest}

\end{document}