[Tex/LaTex] Adding an independent (small) node in a mind map

mindmapstikz-pgf

I used this template, made some alterations and came up with following mind map:

The minimum working example (MWE) can be seen here:

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{matrix,paths.ortho,calc,paths.rectangle,positioning-plus,arrows.meta,shapes,positioning,shadows,trees,mindmap,backgrounds}

\begin{document}

\begin{figure}[!h]
    \centering
    \resizebox{0.8\textwidth}{!}{
        \begin{tikzpicture}[mindmap,
        level 1 concept/.append style={level distance=130,sibling angle=90},
        extra concept/.append style={color=blue!50,text=black}]
        \path[mindmap,concept color=black,text=white]
        node[concept] {Something}
        [clockwise from=0]
        child[concept color=green!50!black] {
            node[concept] (gov) {Something}
            [clockwise from=0]
            child { node[concept] (blub) {Something} }
            child { node[concept] (bla) {Something} }
            child { node[concept] (sep) {Something} }
            [clockwise from=-90]
            child { node[concept] (pau) {Something} }
        }  
        child[concept color=blue] {
            node[concept] (top) {Something}
        }
        child[concept color=red] { 
            node[concept] {Something} 
            [clockwise from=310]
            child { node[concept] (cot) {Something} }
            child { node[concept] (cont) {Something} }
        }
        child[concept color=orange] {
            node[concept] (gen) {Something} 
            [clockwise from=-180]
            child { node[concept] {Something} }
        };

        \begin{pgfonlayer}{background}
        \draw [left color=blue, right color=green!50!black, draw=white, decorate,decoration=circle connection bar] (pau) -- (top);
        \draw [left color=orange, right color=green!50!black, draw=white, decorate,decoration=circle connection bar] (gen) -- (gov);
        \draw [left color=red, right color=blue, draw=white, decorate,decoration=circle connection bar] (cot) -- (top);
        \draw [left color=red, right color=blue, draw=white, decorate,decoration=circle connection bar] (cont) -- (top);
        \end{pgfonlayer}
        \end{tikzpicture}
    }
\end{figure}
\end{document}

One feature of this MWE is that I have included all tikz libraries that I use in my tex file as well as the \resizebox. Please let me know if this does not add any helpful information.

I now want to add an independent node of approximately the same size as the other smaller nodes. What I have in mind looks something like this:

I am aware that this template exists. However, the second independent node would be horribly big. Does anyone have suggestions on how to solve this. I would dearly appreciate it.

Best Answer

You can use the extra concept style for the additional node (this is the exact situation for which the style was designed) and draw the lines with a loop:

\node[fill=blue,circle,font=\scriptsize,extra concept,text=white]
  (additional)
  at (blub|-pau)
 {Something else};
\foreach \Name in {blub,sep,bla}
  \draw[dashed,ultra thick,blue] (additional) -- (\Name);

The result:

The complete code:

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{matrix,calc,,arrows.meta,shapes,positioning,shadows,trees,mindmap,backgrounds}

\begin{document}

\begin{figure}
    \centering
    \resizebox{0.8\textwidth}{!}{%
        \begin{tikzpicture}[mindmap,
        level 1 concept/.append style={level distance=130,sibling angle=90},
        extra concept/.append style={color=blue!50,text=black}]
        \path[mindmap,concept color=black,text=white]
        node[concept] {Something}
        [clockwise from=0]
        child[concept color=green!50!black] {
            node[concept] (gov) {Something}
            [clockwise from=0]
            child { node[concept] (blub) {Something} }
            child { node[concept] (bla) {Something} }
            child { node[concept] (sep) {Something} }
            [clockwise from=-90]
            child { node[concept] (pau) {Something} }
        }  
        child[concept color=blue] {
            node[concept] (top) {Something}
        }
        child[concept color=red] { 
            node[concept] {Something} 
            [clockwise from=310]
            child { node[concept] (cot) {Something} }
            child { node[concept] (cont) {Something} }
        }
        child[concept color=orange] {
            node[concept] (gen) {Something} 
            [clockwise from=-180]
            child { node[concept] {Something} }
        };

        \begin{pgfonlayer}{background}
        \draw [left color=blue, right color=green!50!black, draw=white, decorate,decoration=circle connection bar] (pau) -- (top);
        \draw [left color=orange, right color=green!50!black, draw=white, decorate,decoration=circle connection bar] (gen) -- (gov);
        \draw [left color=red, right color=blue, draw=white, decorate,decoration=circle connection bar] (cot) -- (top);
        \draw [left color=red, right color=blue, draw=white, decorate,decoration=circle connection bar] (cont) -- (top);
        \end{pgfonlayer}

\node[fill=blue,circle,font=\scriptsize,extra concept,text=white]
  (additional)
  at (blub|-pau)
 {Something else};
\foreach \Name in {blub,sep,bla}
  \draw[dashed,ultra thick,blue] (additional) -- (\Name);
\end{tikzpicture}%
}


\end{figure}
\end{document}

As a side note, using [!h] as float position specifier is a recipe for disaster; use a less restrictive option such as [!htp] or, better yet, none at all.

Related Solutions

[Tex/LaTex] Rotate a node but not its content: the case of the ellipse decoration

The source of the difficulty is that ellipses are constructed in a particular way in TikZ. They are paths that start from the x-axis and proceed counter-clockwise around their centre. The vast majority of the time, the exact parametrisation doesn't matter. You appear to have found the one situation where it does!

In the actual question, you only want to be able to mirror the ellipse, and so draw it starting from the negative x-axis (the title of the question suggests a more flexible approach). That's actually not too hard since we can exploit the symmetry of the ellipse. The key is to provide it with a negative x-radius, since then it will start from the negative x-axis (and proceed clockwise, but we could correct for that by negating the y-radius as well). To do this, we interrupt the call from the node shape to the drawing command and flip the sign of the x-radius. The simplest way to do this is to redefine the \pgfpathellipse macro to do the negation and then call the original macro. The following code does this.

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{decorations,shapes,decorations.markings}
\makeatletter
\let\origpgfpathellipse=\pgfpathellipse
\def\revpgfpathellipse#1#2#3{%
  #2%
  \pgf@xa=-\pgf@x
  \origpgfpathellipse{#1}{\pgfqpoint{\pgf@xa}{0pt}}{#3}}
\makeatother

\tikzset{
  reversed ellipse/.style={
    ellipse,
    reverse the ellipse%
  },
  reverse the ellipse/.code={
    \let\pgfpathellipse=\revpgfpathellipse
  }
}
\begin{document}
\begin{tikzpicture}
\node[ellipse,
  draw,
  postaction={
    decorate,
    decoration={
      markings,
      mark=at position 1 with {
        \arrow[line width=5pt,blue]{>}
      }
    }
  }
] at (0,0) {hello world};

\node[reversed ellipse,
  draw,
  postaction={
    decorate,
    decoration={
      markings,
      mark=at position 1 with {
        \arrow[line width=5pt,blue]{>}
      }
    }
  }
] at (0,-2) {hello world};
\end{tikzpicture}

\end{document}

Here's the result:

rotated ellipse

(the arrow got clipped, but you can see where it lies)

[Tex/LaTex] Tikz mindmap with opacity, a different approach to venn diagrams

How about this: I used hexagonal nodes instead of circles. You just need to set the colors and separation, the connections are automatically computed to be the average color of the nodes they connect. A node can be assigned one of two styles, venn and unvenn. While venn draws the node, unvenn makes it transparent. You don't need to remove the =some color when using unvenn, this parameter is simply not used in the definition of unvenn.

The Code

\documentclass[parskip]{scrartcl}
\usepackage[margin=15mm]{geometry}
\usepackage{tikz}
\usetikzlibrary{shapes}

\pgfdeclarelayer{background layer}
\pgfsetlayers{background layer,main}

\begin{document}

\colorlet{abccolor}{gray!50}
\colorlet{acolor}{red!50!gray}
\colorlet{abco\documentclass[parskip]{scrartcl}
\usepackage[margin=15mm]{geometry}
\usepackage{tikz}
\usetikzlibrary{shapes}

\pgfdeclarelayer{background layer}
\pgfsetlayers{background layer,main}

\begin{document}

\colorlet{abccolor}{gray!50}
\colorlet{acolor}{red!50!gray}
\colorlet{abcolor}{orange!50!gray}
\colorlet{bcolor}{yellow!50!gray}
\colorlet{bccolor}{green!50!gray}
\colorlet{ccolor}{blue!50!gray}
\colorlet{accolor}{violet!50!gray}

\pgfmathsetmacro{\nodescenterseparation}{4}

\begin{tikzpicture}
[   venn/.style={regular polygon, regular polygon sides=6,shape border rotate=30, minimum width=3cm,draw,inner sep=0,fill=#1,draw=#1!70!black,very thick},
    unvenn/.style={regular polygon, regular polygon sides=6,shape border rotate=30, minimum width=3.5cm,opacity=0},
]
    \node[venn=abccolor] at (0,0) (abc) {$A\cap B\cap C$};
    \node[venn=acolor] at (0:\nodescenterseparation) (a) {$A$};
    \node[venn=abcolor] at (60:\nodescenterseparation) (ab) {$A\cap B$};
    \node[venn=bcolor] at (120:\nodescenterseparation) (b) {$B$};
    \node[venn=bccolor] at (180:\nodescenterseparation) (bc) {$B\cap C$};
    \node[venn=ccolor] at (240:\nodescenterseparation) (c) {$C$};
    \node[venn=accolor] at (300:\nodescenterseparation) (ac) {$A\cap C$};

    \begin{pgfonlayer}{background layer}
        \fill[abccolor!50!acolor] (abc.corner 6) -- (abc.center) -- (abc.corner 5) -- (a.corner 3) -- (a.center) -- (a.corner 2) -- cycle;
        \fill[abccolor!50!abcolor] (abc.corner 1) -- (abc.center) -- (abc.corner 6) -- (ab.corner 4) -- (ab.center) -- (ab.corner 3) -- cycle;
        \fill[abccolor!50!bcolor] (abc.corner 2) -- (abc.center) -- (abc.corner 1) -- (b.corner 5) -- (b.center) -- (b.corner 4) -- cycle;
        \fill[abccolor!50!bccolor] (abc.corner 3) -- (abc.center) -- (abc.corner 2) -- (bc.corner 6) -- (bc.center) -- (bc.corner 5) -- cycle;
        \fill[abccolor!50!ccolor] (abc.corner 4) -- (abc.center) -- (abc.corner 3) -- (c.corner 1) -- (c.center) -- (c.corner 6) -- cycle;
        \fill[abccolor!50!accolor] (abc.corner 5) -- (abc.center) -- (abc.corner 4) -- (ac.corner 2) -- (ac.center) -- (ac.corner 1) -- cycle;

        \fill[acolor!50!abcolor] (a.corner 2) -- (a.center) -- (a.corner 1) -- (ab.corner 5) -- (ab.center) -- (ab.corner 4) -- cycle;
        \fill[abcolor!50!bcolor] (ab.corner 3) -- (ab.center) -- (ab.corner 2) -- (b.corner 6) -- (b.center) -- (b.corner 5) -- cycle;
        \fill[bcolor!50!bccolor] (b.corner 4) -- (b.center) -- (b.corner 3) -- (bc.corner 1) -- (bc.center) -- (bc.corner 6) -- cycle;
        \fill[bccolor!50!ccolor] (bc.corner 5) -- (bc.center) -- (bc.corner 4) -- (c.corner 2) -- (c.center) -- (c.corner 1) -- cycle;
        \fill[ccolor!50!accolor] (c.corner 6) -- (c.center) -- (c.corner 5) -- (ac.corner 3) -- (ac.center) -- (ac.corner 2) -- cycle;
        \fill[accolor!50!acolor] (ac.corner 1) -- (ac.center) -- (ac.corner 6) -- (a.corner 4) -- (a.center) -- (a.corner 3) -- cycle;
    \end{pgfonlayer}
\end{tikzpicture}

\end{document}

Result with all sets non-empty

enter image description here

Result with ABC, A and BC empty

\node[unvenn=abccolor] at (0,0) (abc) {$A\cap B\cap C$};
\node[unvenn=acolor] at (0:\nodescenterseparation) (a) {$A$};
\node[venn=abcolor] at (60:\nodescenterseparation) (ab) {$A\cap B$};
\node[venn=bcolor] at (120:\nodescenterseparation) (b) {$B$};
\node[venn=bccolor] at (180:\nodescenterseparation) (bc) {$B\cap C$};
\node[unvenn=ccolor] at (240:\nodescenterseparation) (c) {$C$};
\node[venn=accolor] at (300:\nodescenterseparation) (ac) {$A\cap C$};