Fontsize – Changing Font Size in Forest Decision Tree

fontsizeforest

I want to change the font size of the following forest decision tree to \footnotesize. When I add font=\footnotesize to for tree, it only the size of the "Name"s get changed, but not the edge labels ("H" and "T"). If I fiddle with the decision edge label/.style by adding \footnotesize in it, an error would occur:

! TeX capacity exceeded, sorry [input stack size=5000].
\@setfontsize #1#2#3->\@nomath #1
\ifx \protect \@typeset@protect \let \@curr…
l.53 \end{forest}

MWE

\documentclass{article}
\usepackage{mathtools,forest}
\def\getfirst#1;#2\endget{#1}
\def\getsecond#1;#2\endget{#2}
\forestset{declare toks={elo}{}} % edge label options
\begin{document}
\color{red}
\begin{forest}
  anchors/.style={anchor=#1,child anchor=#1,parent anchor=#1},
  for tree={font=\footnotesize,
    s sep=5mm,l=15mm,
    if n children=0{anchors=north}{
    if n=1{anchors=south east}{anchors=south west}},
    content format={$\forestoption{content}$}
  },
  anchors=south, outer sep=2pt,
  nomath/.style={content format=\forestoption{content}},
  dot/.style={tikz+={\draw[#1](.child anchor)circle[radius=2pt];}},
  dot={fill={white}},for descendants={dot={fill}}, % initial node hollow, rest solid
  decision edge label/.style n args=3{
    edge label/.expanded={node[midway,auto=#1,anchor=#2,\forestoption{elo}]{\strut$#3$}}
  },
  decision/.style={if n=1
    {decision edge label={left}{east}{#1}}
    {decision edge label={right}{west}{#1}}
  },
  delay={for descendants={
    decision/.expanded/.wrap pgfmath arg={\getsecond#1\endget}{content},
    content/.expanded/.wrap pgfmath arg={\getfirst#1\endget}{content},
  }},
  [Name,nomath
    [Name;{+\epsilon},nomath
      [;{H}
        [;{H}]
        [;{T}]
      ]
      [;{T}
        [;{H}]
        [;{T}]
      ]
    ]
    [Name;{-\epsilon},nomath
      [;{H}
        [;{H}]
        [;{T}]
      ]
      [;{T}
        [;{H}]
        [;{T}]
      ]
    ]
  ]
\end{forest}
\end{document}

Output

Best Answer

The easiest way to set the entire tree this way is to simply put \footnotesize in a group with the tree. For example:

{\footnotesize
  \begin{forest}
    ...
  \end{forest}%
}

Alternatively, you can set the font for every node in the tree's preamble using

 /tikz/every node/.append style={font=\footnotesize},

\documentclass[tikz,border=10pt,multi]{standalone}
\usepackage{mathtools,forest}
\def\getfirst#1;#2\endget{#1}
\def\getsecond#1;#2\endget{#2}
\forestset{declare toks={elo}{}} % edge label options
\begin{document}
\color{red}
\begin{forest}
  anchors/.style={anchor=#1,child anchor=#1,parent anchor=#1},
  /tikz/every node/.append style={font=\footnotesize},
  for tree={
    font=\footnotesize,
    s sep=5mm,l=15mm,
    if n children=0{anchors=north}{
    if n=1{anchors=south east}{anchors=south west}},
    content format={$\forestoption{content}$},
  },
  anchors=south, outer sep=2pt,
  nomath/.style={content format=\forestoption{content}},
  dot/.style={tikz+={\draw[#1](.child anchor)circle[radius=2pt];}},
  dot={fill={white}},for descendants={dot={fill}}, % initial node hollow, rest solid
  decision edge label/.style n args=3{
    edge label/.expanded={node[midway,auto=#1,anchor=#2,\forestoption{elo}]{\strut$#3$}}
  },
  decision/.style={if n=1
    {decision edge label={left}{east}{#1}}
    {decision edge label={right}{west}{#1}}
  },
  delay={for descendants={
    decision/.expanded/.wrap pgfmath arg={\getsecond#1\endget}{content},
    content/.expanded/.wrap pgfmath arg={\getfirst#1\endget}{content},
  }},
  [Name,nomath
    [Name;{+\epsilon},nomath
      [;{H}
        [;{H}]
        [;{T}]
      ]
      [;{T}
        [;{H}]
        [;{T}]
      ]
    ]
    [Name;{-\epsilon},nomath
      [;{H}
        [;{H}]
        [;{T}]
      ]
      [;{T}
        [;{H}]
        [;{T}]
      ]
    ]
  ]
\end{forest}
\end{document}

Related Solutions

[Tex/LaTex] Changing text font size without changing math font size

You can change the surrounding text font size to 14pt by normal means. And to maintain the math font size to 12pt you could use the \DeclareMathSizes in your preamble. The syntax is:

\DeclareMathSizes{display size}{text size}{script size}{scriptscript size}

So, for instance, you could set:

\DeclareMathSizes{14pt}{12pt}{10pt}{8pt}

Or make all math sizes equal:

\DeclareMathSizes{14pt}{12pt}{12pt}{12pt}

It really depends on your requirements! But adding either code to your document's preamble should achieve what you needed to do.

Reference: @Stephan Kottwitz's answer shown here

[Tex/LaTex] Forest trees: Reduce size of tree node

As Salim Bou pointed out in a comment, the reason the inner sep appears ineffective is that the content of the node itself is rather large, relatively speaking. So the difference between 0.1mm and 0.001mm makes little difference as that only changes the margin around the content from tiny to more tiny.

As Salim Bou suggested, one approach is to delete the code adding the content to the tree's nodes. In this case, the inner sep settings will actually determine the size of all nodes in the tree.

If you only want to adjust the size of that one node, however, you may prefer to override the content later. This will change only that node's content, if set as an argument for that node. Do note that most of the inner sep settings could be simply deleted in this case, with almost no visual affect on the appearance.

I'd also suggest making use of styles to avoid duplicating settings. How best to do this depends on what you need. Here's a possible example which also illustrates the two methods of altering the sizing explained above.

\documentclass[border=10pt]{standalone}
\usepackage{forest}

\begin{document}
\begin{forest}
  for tree={
    s sep'+=5mm,
    l'+=5mm,
  },
  my circle/.style={
    circle, fill=#1,
  },
  red circle/.style={
    my circle=red, inner sep=#1mm,
  },
  black circle/.style={
    my circle=black, inner sep=#1mm,
  },
  black hole/.style={
    circle, draw=black, inner sep=#1mm,
  }
  [, black circle=1
    [, red circle=0.5
      [, black hole=0.1]
      []
      [, black hole=0.1]
      []
    ]
    []
    [, red circle=0.5
      [, red circle=0.25
          [, black hole=0.1]
          [, black hole=0.1]
          [, black hole=0.1]
          [, black hole=0.001]
      ]
          []
          []
      [, black hole=0.1]
    ]
    [, red circle=0.5]
  ]
\end{forest}
\begin{forest}
  for tree={
    delay={where content={}{content={\phantom{00}}}{}},
    s sep'+=5mm,
    l'+=5mm,
  },
  my circle/.style={
    circle, fill=#1,
  },
  red circle/.style={
    my circle=red, inner sep=#1mm,
  },
  black circle/.style={
    my circle=black, inner sep=#1mm,
  },
  black hole/.style={
    circle, draw=black, inner sep=#1mm,
  }
  [, black circle=1
    [, red circle=0.5
      [, black hole=0.1]
      []
      [, black hole=0.1]
      []
    ]
    []
    [, red circle=0.5
      [, red circle=0.25
          [, black hole=0.1]
          [, black hole=0.1]
          [, black hole=0.1]
          [, black hole=0.001, before typesetting nodes={content=}]%%% <------------- ??
      ]
          []
          []
      [, black hole=0.1]
    ]
    [, red circle=0.5]
  ]
\end{forest}
\end{document}

The tree on the left shows the nodes with sizes determined by their inner seps. The tree on the right shows them with the phantom 00 as content, excepting the single tiny node where this is overridden.

MWE

Output

Best Answer

Related Solutions

[Tex/LaTex] Changing text font size without changing math font size

[Tex/LaTex] Forest trees: Reduce size of tree node

Related Question