I am very new at tikz or any type of latex graphics. I need to generate a latex graphics for this diagram. I have tried to modify an example in: http://texample.net/tikz/examples/observer-estimator/ But I can't obtain the diagram that I need. Can anyone help me?

enter image description here

% Observer/Estimator
% Author: Dominik Haumann

\usepackage[utf8x]{inputenc} % utf8 encoding
\usepackage[T1]{fontenc} % use T1 fonts
\usepackage{amsmath} % nice math symbols
\usepackage{bm} % bold math
\usepackage{color} % change text color


:Title: Observer/Estimator
:Slug: observer-estimator
:Author: Dominik Haumann

An example of an observer with a feedback loop. By using the matrix
tikzlibrary it is shown how to easily place and link the nodes appropriately
in order to create very complex block diagrams. Additionally, this example
shows how to use line decorations as well as how to use an offset for arrow

I have modify the example by  Dominik Haumann. Rubert

\usetikzlibrary{decorations.pathmorphing} % for snake lines
\usetikzlibrary{matrix} % for block alignment
\usetikzlibrary{arrows} % for arrow heads
\usetikzlibrary{calc} % for manimulation of coordinates
% TikZ styles for drawing
\tikzstyle{block} = [draw,rectangle,thick,minimum height=2em,minimum width=2em]
\tikzstyle{sum} = [draw,circle,inner sep=0mm,minimum size=2mm]
\tikzstyle{connector} = [->,thick]
\tikzstyle{line} = [thick]
\tikzstyle{branch} = [circle,inner sep=0pt,minimum size=1mm,fill=black,draw=black]
\tikzstyle{guide} = []
\tikzstyle{snakeline} = [connector, decorate, decoration={pre length=0.2cm,
                         post length=0.2cm, snake, amplitude=.4mm,
                         segment length=2mm},thick, magenta, ->]

\renewcommand{\vec}[1]{\ensuremath{\boldsymbol{#1}}} % bold vectors
\def \myneq {\skew{-2}\not =} % \neq alone skews the dash


  \begin{tikzpicture}[scale=1, auto, >=stealth']
    % node placement with matrix library: 5x4 array
    \matrix[ampersand replacement=\&, row sep=1cm, column sep=0.4cm] {
      \node[block] (F1) {$\gg d$}; \&
      \node[branch] (u1) {}; \&
      \node[block] (f1) {$(x_{n-r_1}+x_{n-s_1})\mod m$}; \& \\

      \node[block] (L1) {$(y_{n-r_2}+y_{n-s_2})\mod m$};\&
      \node [sum] (e1) {}; \\

      \node[sum] (v1) {}; \&
      \node[block] (o1) {$(z_{n-r_3}+z_{n-s_3})\mod m$};
      \node[guide] (i1) {}; \& \& \& \& \\

    % now link the nodes
    \draw [line] (F1) -- (f1);
    \draw [connector] (f1) -| node[near end] {$\vec{y}_i$} (e1);
    \draw [connector] (e1) -- (L1);
    \draw [connector] (L1) -| (v1);
    \draw [connector] (v1) -- node {} (o1);
    \draw [connector] (u1) |- (v1);
    \draw [connector] (o1) -| node[pos=0.96] {$-$} node [near end, swap]
                      {$\widetilde{\vec{y}}_i$} (e1);

    % draw the snake lines with offset (using the calc library)


%This  is what I've tried to do... :-(

  \tikzset{packet/.style={rectangle, draw, very thick}}
  \tikzset{xor/.style={circle, draw, very thick}}

 \node[packet] (p1) at (0,1.5) {$\gg d1$};
  \node[xor] (p2) [right=6mm of p1] {};
   \node[branch] (s)  [below=-.7mm of p2 ] {};
  \draw [->] (p1) -- (p2);
  \node[branch] (c1)  [below left=7.5mm of p1] {};
    \node[packet] (p3) [below right=5mm of p2] {$(x_{n-r_1}+x_{n-s_1})\mod m$};
   \draw [line] (c1) -- (p3);
    \draw [->] (c1) |-(p1);
   \node[pto] (co) [right=5mm of p1] {$+$};

  \node[packet] (p4) at (0,-1.5) {$\gg d$};
  \node[xor] (p5)  [right=5mm of p4] {$+$};
  \draw [->] (p4) -- (p5);

  %\node[packet] (p6) at (5,-1.5) {$(y_{n-r_2}+y_{n-s_2})\mod m$};

  • What is the actual question? Commented Aug 13, 2017 at 16:47
  • 11
    @Dr.ManuelKuehner I think that the actual question is "can you do this for me?" Commented Aug 13, 2017 at 16:49
  • this is a block diagram by the way not a tree
    – percusse
    Commented Aug 13, 2017 at 16:50
  • @Rubert Antonio Can you pleas provide a MWE showing your attempts so far? Commented Aug 13, 2017 at 16:51
  • 1
    your mwe generate nice picture. is this picture not what you like to have? how then looks desired image?. welcome to tex.se!
    – Zarko
    Commented Aug 13, 2017 at 17:51

1 Answer 1


enter image description here

\documentclass[tikz, margin=3mm]{standalone}
\usepackage[utf8]{inputenc} % instead of utf8x 
\usepackage[T1]{fontenc} % use T1 fonts
\usepackage{amsmath}     % nice math symbols
%\usepackage{bm}         % not used
%\renewcommand{\vec}[1]{\ensuremath{\boldsymbol{#1}}} % not used
%\usepackage{xcolor}     % instead of color

\usetikzlibrary{arrows.meta, % for arrow heads

%\def \myneq {\skew{-2}\not =} % \neq alone skews the dash

    \begin{tikzpicture}[auto, swap,
node distance = 3mm and 12mm,
 block/.style = {rectangle, draw,thick, minimum size=8mm,
                 inner sep=2mm, outer sep=0mm},
   sum/.style = {circle, draw=black, minimum size=6mm,
            append after command={\pgfextra
            \draw[very thick,shorten >=1mm,shorten <=1mm,-]
            (\tikzlastnode.north) edge (\tikzlastnode.south)
            (\tikzlastnode.west)   --  (\tikzlastnode.east);
            node contents={}},
    LA/.style = {thick, -Stealth}
\node (n11) [block]                         {$\gg d$};
\node (n12) [sum, right=of n11];
\node (n13) [block, below right=of n12]     {$(x_{n-r}+x_{n-s})\mod m$};
\coordinate[right=of n13]  (n14);
    \draw[LA]   (n11) edge (n12)
                (n14) to ["$\{z_n\}$"] (n13);
    \draw[LA]   (n12) -| (n14)
                (n13) -| (n12) ;
\node (n21) [block, below=of n11 |- n13]    {$\gg d$};
\node (n22) [sum, right=of n21];
\node (n23) [block, below right=of n22]     {$(y_{n-r}+y_{n-s})\mod m$};
\coordinate[right=of n23]   (n24);
\coordinate[left =of n21]   (a1);
    \draw[LA]   (n21) edge (n22)
                (n24) edge ["$\{y_n\}$"] (n23)
                (a1) -- (n21) ;
    \draw[LA]   (n12 |- n13) -| (a1)
                (n22) -| (n24)
                (n23) -| (n22);
\node (n31) [block, below=of n21 |- n23]    {$\gg d$};
\node (n32) [sum, right=of n31];
\node (n33) [block, below right=of n32]     {$(z_{n-r}+z_{n-s})\mod m$};
\coordinate[right=of n33]   (n34) ;
\coordinate[left =of n31]   (a2);
\coordinate[left =of a2]    (a3);
    \draw[LA]   (n31) -- (n32)
                (n34) edge ["$\{x_n\}$"] (n33)
                (a2) edge (n31)
                (n32 |- n33) -| (a3) |- (n11);
    \draw[LA]   (n22 |- n23) -| (a2)
                (n32) -| (n34)
                (n33) -| (n32) ;
\node (n41) [sum, right=of n24];
\node (n42) [block, rounded corners, below right=of n41] {$\{w_n\}$};
    \draw[LA]   (n14) -| (n41);
    \draw[LA]   (n34) -| (n41);
    \draw[LA]   (n41) -| (n42);
  • @RubertAntonio, you are welcome. if you liked solution and if it solve your problem, you can vote it and even accept (by clicking on up-pen and check mark at top left side of answer) :-)
    – Zarko
    Commented Aug 19, 2017 at 23:18

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