[Tex/LaTex] Style inheritance in TikZ trees

nodestikz-pgftikz-stylestikz-trees

As I read the rule for style inheritance in a tree (pgfmanual 18.4, page 215), the naked [rect] below should mean that the node labeled "empty" be rectangular. But it's not. What am I doing wrong?

Thanks.

\begin{tikzpicture}[->,sibling distance=7mm, level distance=5mm,
rect/.style={inner sep=0pt,minimum size=2mm,draw,rectangle},
alive/.style={fill=orange,draw},
emph/.style={thick,yellow}]
\node[rect] (MRCA) at (2.5,4) {}
    [rect]
    child {node[alive](high){}
        child {node {empty}
        }
    }
;
\end{tikzpicture}

Best Answer

I don't find the manual's explanation completely clear either. But the point is that child is a path operation and an option xx placed at the following point

\node {root}
   [xx]
   child ...

applies to all the child paths. Now some options to paths get inherited by nodes on those paths, others do not. For example a colour blue in \draw[blue] (0,0) -- (1,0) node {x}; will apply both to the path and the node; whereas \draw[rectangle] (0,2) -- (1,2) node {x}; will not have any effect. Node styles can be passed via every node/.style:

Demonstration output

\documentclass{article}

\usepackage{tikz}

\begin{document}

\begin{tikzpicture}
  \draw[blue] (0,2) -- (1,2) node {x};
  \draw[rectangle,draw] (0,1) -- (1,1) node {x};
  \draw[every node/.style={rectangle,draw}] (0,0) -- (1,0) node {x};
\end{tikzpicture}

\end{document}

Similarly in your example there is an every child node/.style that can be used.

Sample output

\documentclass{article}

\usepackage{tikz}

\begin{document}

\begin{tikzpicture}[->,
rect/.style={inner sep=2pt,minimum size=2mm,draw,rectangle},
brect/.style={inner sep=2pt,minimum size=2mm,draw,rectangle,blue},
alive/.style={fill=orange,draw}]
\node[rect] at (2.5,4) {}
    [blue]
    child {node[alive] {}
        child {node {empty}
        }
    }
;
\node[rect] at (5.5,4) {}
  [every child node/.style=rect]
    child {node[alive] {}
        child {node {empty}
        }
    }
;
\node[rect] at (8.5,4) {}
  [brect]
    child {node[alive] {}
        child {node {empty}
        }
    }
;
\end{tikzpicture}

\end{document}

Notice how the brect style that contains a shape plus the colour blue, when applied to a path just passes on the colour.

Related Solutions

[Tex/LaTex] How to define the default vertical distance between nodes

I don't really get the question so I hope this is what you wanted. If you include a full document (such that we copy paste and see the problem on our systems) things are much more easier.

Here, you can change the default setting within a scope but your block style had a node distance which was resetting every time it is issued. I've made it 2mm such that we can see the difference easier.

\documentclass[tikz]{standalone}
\usetikzlibrary{arrows,shapes.geometric,positioning}

\begin{document}
\begin{tikzpicture}[decision/.style={diamond, draw, text width=4.5em, text badly centered, node distance=3.5cm, inner sep=0pt},
                    block/.style   ={rectangle, draw, text width=6em, text centered, rounded corners, minimum height=4em, minimum height=2em},
                    cloud/.style   ={draw, ellipse, minimum height=2em},
                    line/.style    ={draw,-latex'},
                    node distance = 1cm, 
                    auto]
    \node [block] (1st) {1st};
    \node [block, right= of 1st]  (2nd1) {2nd1};
\begin{scope}[node distance=2mm and 10mm]%Here we change it for everything inside this scope
    \node [block, above= of 2nd1] (2nd2) {2nd2};
    \node [block, below= of 2nd1] (2nd3) {2nd3};
    \node [block, right= of 2nd1] (3rd1) {3rd1};
    \node [block, above= of 3rd1] (3rd2) {3rd2};
    \node [block, above= of 3rd2] (3rd3) {3rd3};
\end{scope}
    \node [block, below= of 3rd1] (3rd4) {3rd4};
    \node [block, below= of 3rd4] (3rd5) {3rd5};

    \path [line] (1st) -- (2nd1);
    \path [line] (2nd1) -- (2nd2);
    \path [line] (2nd1) -- (2nd3);
    \path [line] (2nd2) -- (3rd3);
    \path [line] (2nd1) -- (3rd1);
    \path [line] (1st) -- (2nd1);
\end{tikzpicture}
\end{document}

enter image description here

[Tex/LaTex] Styles in TikZ trees not working as expected

Just a quick demonstration with Forest. The major advantages of Forest lie in its power, flexibility and concise syntax. Regularities in content and styling can be turned into automated configuration rules and trees themselves can be specified very concisely. Since Forest is based on TikZ, the power of the host package is also available.

For example,

\begin{forest}
  bordered tree,
  [
    [x, border
      [x1, acc, for descendants=border
        [][][]
      ]
      [x2, rej]
      [x3, for children=border
        [][][]
      ]
    ]
  ]
\end{forest}

specifies the target tree:

while the following partly explains the first and partly shows one or two additional tricks,

\begin{forest}
  bordered tree,
  [
    [x, border, normal
    [x1, acc, for descendants=border, label=left:\texttt{for descendants}
        [][.,label=left:bordered children [][]][]
      ]
      [x2, rej]
      [x3, normal, for children=border, label=right:\texttt{for children}
        [][.,label=right:unbordered children [][]][, for current and ancestors={edge+=blue}]
      ]
    ]
  ]
\end{forest}

which produces:

Complete code:

\documentclass[border=10pt]{standalone}
\usepackage{forest}
\forestset{
  declare boolean={border}{0},
  bordered tree/.style={
    for tree={
      minimum size=4mm, 
      inner sep=0.5mm,
      edge+={semithick},
      semithick,
    },
    before typesetting nodes={
      where border={
        edge+={dashed, draw},
      }{},
      where={isodd(n_children)}{
        tempcounta/.process={
          Ow+n {n children}{(##1+1)/2}
        },
        for n={
          >  R {tempcounta} % doesn't work to plug the above in directly ??'
        }{calign with current edge},
      }{},
      where content={}{}{normal},
    },
  },
  /tikz/.cd,
  normal/.style={circle,draw},
  invis/.style={draw=none},
  acc/.style={circle,thick,draw=green!50,fill=green!2},
  rej/.style={circle,thick,draw=red!50,fill=red!20},
}
\begin{document}
\begin{forest}
  bordered tree,
  [
    [x, border
      [x1, acc, for descendants=border
        [][][]
      ]
      [x2, rej]
      [x3, for children=border
        [][][]
      ]
    ]
  ]
\end{forest}
\begin{forest}
  bordered tree,
  [
    [x, border, normal
    [x1, acc, for descendants=border, label=left:\texttt{for descendants}
        [][.,label=left:bordered children [][]][]
      ]
      [x2, rej]
      [x3, normal, for children=border, label=right:\texttt{for children}
        [][.,label=right:unbordered children [][]][, for current and ancestors={edge+=blue}]
      ]
    ]
  ]
\end{forest}
\end{document}

Best Answer

Related Solutions

[Tex/LaTex] How to define the default vertical distance between nodes

[Tex/LaTex] Styles in TikZ trees not working as expected

Related Question