Tikz matrix: Align node to center of multirow

Question

I am having an issue with TIKZ, or matrices ... I don't know which :)

All I want to do is to move/align my Blackbox in the center of this one (multi-)row while having the arrows spread evenly on the sides (see below). Somehow it does not work. I tried with tabular and array, but still no luck.

Any ideas? Thanks!!

(I'm no hero with latex, please be kind!)

\documentclass[10pt]{article} %
\usepackage{tikz} %
\usepackage{multirow} %
\usetikzlibrary{automata,arrows} %
\usepackage[active,tightpage]{preview}%
\PreviewEnvironment{tikzpicture}%
\setlength\PreviewBorder{1em}%
\begin{document}

    \begin{tikzpicture}
    [auto,
    block/.style ={rectangle, draw=black, thick, fill=black!85, text width=8em, text centered, text=white, rounded corners, minimum height=10em},
    line/.style ={draw, thick, -latex}]

    \matrix [column sep=15mm,row sep=6mm]
    {
    \node[] (in1) {Eingang 1} ; & \multirow{6}{*}{\node[block] (bb) {Blackbox};} & \node[] (out1) {Ausgang 1} ; \\
    \node[] (in2) {Eingang 2} ; & & \node[] (out2) {Ausgang 2} ; \\
    \node[] (in3) {Eingang 3} ; & & \node[] (out3) {Ausgang 3} ; \\
    \node[] (in4) {Eingang 4} ; & & \node[] (out4) {Ausgang 4} ; \\
    \node[] (in5) {Eingang 5} ; & & \node[] (out5) {Ausgang 5} ; \\
    \node[] (in6) {Eingang 6} ; & & \node[] (out6) {Ausgang 6} ; \\
    };

    \begin{scope}[every path/.style=line]
    \path (in1.east) -- ([yshift=3em]bb.west);
    \path (in2.east) -- ([yshift=2em]bb.west);
    \path (in3.east) -- ([yshift=1em]bb.west);
    \path (in4.east) -- ([yshift=-1em]bb.west);
    \path (in5.east) -- ([yshift=-2em]bb.west);
    \path (in6.east) -- ([yshift=-3em]bb.west);

    \path ([yshift=3em]bb.east) -- (out1.west);
    \path ([yshift=2em]bb.east) -- (out2.west);
    \path ([yshift=1em]bb.east) -- (out3.west);
    \path ([yshift=-1em]bb.east) -- (out4.west);
    \path ([yshift=-2em]bb.east) -- (out5.west);
    \path ([yshift=-3em]bb.east) -- (out6.west);
    \end{scope}

    \end{tikzpicture}

\end{document}

Answer 1

Is this what you want?

The following method first places the two sets of nodes on both sides, which creates a bounding box. Then, it puts the black box at the center of the bounding box. You need to load the positioning library. And seems that the automata library is not needed.

Code

\documentclass[10pt]{article} %
\usepackage{tikz} %
\usepackage{multirow} %
\usetikzlibrary{arrows,positioning} %
\usepackage[active,tightpage]{preview}%
\PreviewEnvironment{tikzpicture}%
\setlength\PreviewBorder{1em}%
\begin{document}

    \begin{tikzpicture}
    [auto,
    block/.style ={rectangle, draw=black, thick, fill=black!85, text width=8em, text centered, text=white, rounded corners, minimum height=10em},
    line/.style ={draw, thick, -latex}]

    \node(in1){Eingang 1};
    \foreach\innum[count=\inlag] in {2,...,6}
        \node(in\innum)[below=of in\inlag]{Eingang \innum};

    \node(out1)[right=50mm of in1]{Ausgang 1};
    \foreach\outnum[count=\outlag] in {2,...,6}
        \node(out\outnum)[below=of out\outlag]{Ausgang \outnum};

    \node[block] (bb) at(current bounding box.center) {Blackbox};

    \begin{scope}[every path/.style=line]
    \path (in1.east) -- ([yshift=3em]bb.west);
    \path (in2.east) -- ([yshift=2em]bb.west);
    \path (in3.east) -- ([yshift=1em]bb.west);
    \path (in4.east) -- ([yshift=-1em]bb.west);
    \path (in5.east) -- ([yshift=-2em]bb.west);
    \path (in6.east) -- ([yshift=-3em]bb.west);

    \path ([yshift=3em]bb.east) -- (out1.west);
    \path ([yshift=2em]bb.east) -- (out2.west);
    \path ([yshift=1em]bb.east) -- (out3.west);
    \path ([yshift=-1em]bb.east) -- (out4.west);
    \path ([yshift=-2em]bb.east) -- (out5.west);
    \path ([yshift=-3em]bb.east) -- (out6.west);
    \end{scope}

    \end{tikzpicture}

\end{document}

Output

Answer 2

What you have is a matrix of nodes in which \multirow won't work. You have to a new row at the center for the black box. To change the excess vertical space, you can use \\[<dimen>] as in

\node[] (in3) {Eingang 3} ; & & \node[] (out3) {Ausgang 3} ; \\[-2.3cm]
                  &    \node[block] (bb) {Blackbox};   &          \\[-2.3cm]

Full code

\documentclass[10pt]{article} %
\usepackage{tikz} %
\usepackage{multirow} %
\usetikzlibrary{automata,arrows} %
\usepackage[active,tightpage]{preview}%
\PreviewEnvironment{tikzpicture}%
\setlength\PreviewBorder{1em}%
\begin{document}

    \begin{tikzpicture}
    [auto,
    block/.style ={rectangle, draw=black, thick, fill=black!85, text width=8em, text centered, text=white, rounded corners, minimum height=10em},
    line/.style ={draw, thick, -latex}]

    \matrix [column sep=15mm,row sep=6mm]
    {
    \node[] (in1) {Eingang 1} ; &  & \node[] (out1) {Ausgang 1} ; \\
    \node[] (in2) {Eingang 2} ; & & \node[] (out2) {Ausgang 2} ; \\
    \node[] (in3) {Eingang 3} ; & & \node[] (out3) {Ausgang 3} ; \\[-2.3cm]
                  &    \node[block] (bb) {Blackbox};   &          \\[-2.3cm]
    \node[] (in4) {Eingang 4} ; & & \node[] (out4) {Ausgang 4} ; \\
    \node[] (in5) {Eingang 5} ; & & \node[] (out5) {Ausgang 5} ; \\
    \node[] (in6) {Eingang 6} ; & & \node[] (out6) {Ausgang 6} ; \\
    };

    \begin{scope}[every path/.style=line]
    \path (in1.east) -- ([yshift=3em]bb.west);
    \path (in2.east) -- ([yshift=2em]bb.west);
    \path (in3.east) -- ([yshift=1em]bb.west);
    \path (in4.east) -- ([yshift=-1em]bb.west);
    \path (in5.east) -- ([yshift=-2em]bb.west);
    \path (in6.east) -- ([yshift=-3em]bb.west);

    \path ([yshift=3em]bb.east) -- (out1.west);
    \path ([yshift=2em]bb.east) -- (out2.west);
    \path ([yshift=1em]bb.east) -- (out3.west);
    \path ([yshift=-1em]bb.east) -- (out4.west);
    \path ([yshift=-2em]bb.east) -- (out5.west);
    \path ([yshift=-3em]bb.east) -- (out6.west);
    \end{scope}

    \end{tikzpicture}

\end{document}

Answer 3

This is what I do now, thanks to all of you who answered!

\documentclass[10pt]{article} %
\usepackage{tikz} %
\usepackage{multirow} %
\usetikzlibrary{arrows,positioning} %
\usepackage[active,tightpage]{preview}%
\PreviewEnvironment{tikzpicture}%
\setlength\PreviewBorder{1em}%
\begin{document}

    \begin{tikzpicture}
    [auto,
    block/.style ={rectangle, draw=black, thick, fill=black!85, text width=8em, text centered, text=white, rounded corners, minimum height=10em},
    line/.style ={draw, thick, -latex},
    nodel/.style={text width=9em, align=right, anchor=east}, % change width for long text
    noder/.style={text width=9em, align=left, anchor=west}    
    ]

    \node(in1){}; %Eingang 1
    \foreach\innum[count=\inlag] in {2,...,6}
        \node(in\innum)[below=of in\inlag]{}; %Eingang \innum

    \node(out1)[right=60mm of in1]{}; %Ausgang 1
    \foreach\outnum[count=\outlag] in {2,...,6}
        \node(out\outnum)[below=of out\outlag]{}; %Ausgang \outnum

    \node[block] (bb) at(current bounding box.center) {Blackbox};

    \begin{scope}[every node/.style=nodel]
        \node[] at (in1) {This is really long text for only one node};
        \node[] at (in2) {Very short!};
        \node[] at (in3) {Here's some more text that needs to fit my node};
        \node[] at (in4) {Here's some more text};
        \node[] at (in5) {Nothing new here};
        \node[] at (in6) {Nothing new here};
    \end{scope}

    \begin{scope}[every node/.style=noder]
        \node[] at (out1) {Not as much};
        \node[] at (out2) {Long text, see above};
        \node[] at (out3) {Short! Or maybe not as short as I thought. Maybe too much};
        \node[] at (out4) {Short};
        \node[] at (out5) {Something else over here};
        \node[] at (out6) {Something else over here};
    \end{scope}

    \begin{scope}[every path/.style=line]
        \path (in1.east) -- ([yshift=3em]bb.west);
        \path (in2.east) -- ([yshift=2em]bb.west);
        \path (in3.east) -- ([yshift=1em]bb.west);
        \path (in4.east) -- ([yshift=-1em]bb.west);
        \path (in5.east) -- ([yshift=-2em]bb.west);
        \path (in6.east) -- ([yshift=-3em]bb.west);

        \path ([yshift=3em]bb.east) -- (out1.west);
        \path ([yshift=2em]bb.east) -- (out2.west);
        \path ([yshift=1em]bb.east) -- (out3.west);
        \path ([yshift=-1em]bb.east) -- (out4.west);
        \path ([yshift=-2em]bb.east) -- (out5.west);
        \path ([yshift=-3em]bb.east) -- (out6.west);
    \end{scope}

    \end{tikzpicture}

\end{document}