[Tex/LaTex] Write easily a TIKZ flowchart

diagramsenvironmentstikz-arrowstikz-pgf

I created a npm package to write easily a TIKZ flowchart. Flowtex facilitates maintenance of a flowchart. Such as the insertion of new nodes or the positioning of the nodes as a function of others.
I hope it will be as useful to you as for me.

https://www.npmjs.com/package/flowtex

Using flowtex.sty on github based on Creating Flowcharts with TikZ

tutorial & doc

Flowchart

Flowtex Code

flowchart.offsetX("3");
  N('Start').belowGoto(
    P('k <- 0').belowGoto(
      loop = IO('Loop ?').belowGoto(
        D('Yes or No ?').offsetY(-1) // use offsetY with D
         .rightGoto(kp1 = P('k <- k + 1')).topLabel('yes')
         .belowGoto( // use offsetY for this node because is immediatly below of D
          P('Print k').offsetY(-1).belowGoto(
            P('Stop')
          ).leftLabel('exit')
        ).leftLabel('no')
      ).leftLabel('Looping')
    ).leftLabel('Start loop')
  ).leftLabel('Init');
  kp1.goto(loop).brokenArrow();

LaTeX code using TIKZ

\begin{center}
  \begin{tikzpicture}[node distance=2cm]
    \node (node0) [startstop] {Start};
    \node (node1) [process, below of=node0] {k $\leftarrow$ 0};
    \node (node2) [io, below of=node1] {Loop ?};
    \node (node3) [decision, below of=node2, yshift=-1cm] {Yes or No ?};
    \node (node4) [process, right of=node3, xshift=3cm] {k $\leftarrow$ k + 1};
    \node (node5) [process, below of=node3, yshift=-1cm] {Print k};
    \node (node6) [process, below of=node5] {Stop};
    \draw [arrow] (node3) --node[anchor=south] {yes} (node4);
    \draw [arrow] (node3) --node[anchor=east] {no} (node5);
    \draw [arrow] (node5) --node[anchor=east] {exit} (node6);
    \draw [arrow] (node2) --node[anchor=east] {Looping} (node3);
    \draw [arrow] (node1) --node[anchor=east] {Start loop} (node2);
    \draw [arrow] (node0) --node[anchor=east] {Init} (node1);
    \draw [arrow] (node4) |- (node2);
  \end{tikzpicture}
\end{center}

Currently I use \input to insert the generated LaTeX code.
But, I would like create a LaTeX command like this:

\begin{flowtex}
Here, the Flowtex code.
\end{flowtex}

Would you know how to do?

Best Answer

An alternative to the @A.Ellet answer (both consider the first version of your question):

 \documentclass[border=3mm,
                tikz]{standalone}
\usetikzlibrary{arrows.meta,
                calc, chains,
                quotes,
                positioning,
                shapes.geometric}

\begin{document}
  \begin{tikzpicture}[
    node distance = 8mm and 16mm,
      start chain = A going below,
      base/.style = {draw, minimum width=32mm, minimum height=8mm,
                     align=center, on chain=A},
 startstop/.style = {base, rounded corners, fill=red!30},
   process/.style = {base, fill=orange!30},
        io/.style = {base, trapezium, 
                     trapezium left angle=70, trapezium right angle=110,
                     fill=blue!30},
  decision/.style = {base, diamond, fill=green!30},
  every edge quotes/.style = {auto=right}]
                    ]
\node [startstop]       {Start};            % <-- A-1
\node [process]         {k $\gets$ 0};
\node [io]              {Loop ?};
\node [decision]        {Yes or No ?};
\node [process]         {Print k};
\node [process]         {Stop};             % <-- A-6
%
\node [process,                             % <-- A-7
       right=of A-4]    {k $\gets$ k + 1};
%%
\draw [arrows=-Stealth] 
    (A-1) edge["init"]          (A-2)
    (A-2) edge["start stop"]    (A-3)
    (A-3) edge["looping"]       (A-4)
    (A-4) edge["no"]            (A-5)
    (A-5) edge["exit"]          (A-6)
    (A-4) edge["yes"']          (A-7)       % <-- by ' is swapped label position
    (A-7) |- ($(A-2.south east)!0.5!(A-3.north east)$)
          -| ([xshift=7mm] A-3.north);
  \end{tikzpicture}
\end{document}

From comparison of both solution you can observe the following main differences:

nodes in main branch are set as chain (this significantly simplify code)
for node names are used names which is defined by chain
for nodes' common parameters is defined new style named base
for drawing edges between nodes are used quotes package by which syntax for writing edges labels significantly shorter needed code.

The compilation of above MWE (Minimal Working Example) produce similar picture as is shown in @A.Ellett answer with important differences: the feedback edge is drawn more correct (according to my opinion).

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] 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

Best Answer

Related Solutions

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

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

Related Question