# Mindmap sibling angle in Tikz

I am using the following tikz example (original source)

MWE:

% Author: Till Tantau
% Source: The PGF/TikZ manual
\documentclass{article}

\usepackage{tikz}
\usetikzlibrary{mindmap,trees}
\begin{document}
\pagestyle{empty}
\begin{tikzpicture}
\path[mindmap,concept color=black,text=white]
node[concept] {Computer Science}
[clockwise from=0]
child[concept color=green!50!black] {%
node[concept] {practical}
[clockwise from=90]
child {node[concept] {algorithms} }
child {node[concept] {data structures} }
child {node[concept] {pro\-gramming languages} }
child {node[concept] {software engineer\-ing} }
}
child[concept color=blue] {%
node[concept] {applied}
[clockwise from=-30]
child {node[concept] {databases} }
child {node[concept] {WWW} }
}
child[concept color=red] {node[concept] {technical} }
child[concept color=orange] {node[concept] {theoretical} };
\end{tikzpicture}\end{document}


Output:

Where each child is spread 60 degrees apart. I presume you control this spacing with sibling angle=60 (got the idea from here), but I can't use it to change the spacing. Could someone modify the MWE to illustrate how to use it. I would very much appreciate it if you could use a different angle for each branch (including the main branch). Thank you.

EDIT: There seems to be some confusion as people think I want to space things out randomly. What I want is this instead, if a node has two children, I want to define the spacing to be 180 degrees, if it has 3 children, I want the spacing to be 120 degrees, 4 children, 90 degrees, 5 children 72 degrees and so on. As is, I must have 6 children for it to not look weird.

-
Within the example that you suggested: Scientific interactions, syntax child [grow=-10, level distance=160] is used to place child at certain angle and distance from its parent concept. Is this what you want? – Ignasi Jun 11 '13 at 7:43
You can also give node position: child[concept color=orange ] {node[concept] at (-3,-2) {theoretical} }; – Penbeuz Jun 11 '13 at 7:47
The original source for your example is pgfmanual. There you find a comment which says note that 'sibling angle' can only be defined in 'level 1 concept/.append style={}'. – Ignasi Jun 11 '13 at 7:50
@Ignasi sadly I am not sure what that means – puk Jun 11 '13 at 8:49
Means that sibling angle has to be defined for every level, it's not possible to apply it to a particular concept. If you want to apply diferent angles to every concept whithin a certain level, you must use grow or at syntax. – Ignasi Jun 11 '13 at 9:00

The style set angles for level is used to append the correct sibling distance for level #1.

It can either used inside the level style or possibly in a .listed option.

Usage should vary depending on the use-case in a real document. It may preferable to append set angles for level to grow cyclic or create a custom special grow cyclic that used this solution.

## Code

\documentclass[tikz,convert=false]{standalone}
\usetikzlibrary{mindmap,trees,graphs}
\tikzset{
set angles for level/.style={level #1/.append style={sibling angle=360/\the\tikznumberofchildren}},
level/.append style={set angles for level=#1}% solution 1
}
\begin{document}
\begin{tikzpicture}
\path[
mindmap,
concept color=black,
text=white,
grow cyclic,
nodes=concept,
%    set angles for level/.list={1,...,4}% solution 2
]
node {Computer Science}
child[concept color=green!50!black] {%
node {practical}
child {node {algorithms} }
child {node {data structures} }
child {node {pro\-gramming languages} }
child {node {software engineer\-ing} }
child {node {and a fifth}}
}
child[concept color=blue] { node[concept] {applied}
child {node {databases} }
child {node {WWW} }
}
child[concept color=red] {node {technical} }
child[concept color=orange] {node {theoretical} };
\end{tikzpicture}
\end{document}


## Output

-
Thank you, that is exactly what I was looking for. – puk Jun 12 '13 at 0:05