# Is there an wasy way to program in Tikz something like the one in the image?

I am able of doing the hexagons and the rectangle, as well as all the nodes and so on. My problem is if there is an easy way to draw the blue arrows of the image, knowing that I have given to tikzpicture the coordinate of each hexagon.

\begin{scope}[xshift=-1.5cm,yshift=7.83cm]
\node[draw,circle,inner sep=2.5pt,minimum size=2pt,fill=black] (A) at (0:1cm) {};
\node[draw,circle,inner sep=2.5pt,minimum size=2pt] (B) at (60:1cm) {};
\node[draw,circle,inner sep=2.5pt,minimum size=2pt,fill=black] (C) at (120:1cm) {};
\node[draw,circle,inner sep=2.5pt,minimum size=2pt] (D) at (180:1cm) {};
\node[draw,circle,inner sep=2.5pt,minimum size=2pt,fill=black] (E) at (240:1cm) {};
\node[draw,circle,inner sep=2.5pt,minimum size=2pt] (F) at (300:1cm) {};
\draw[thick] (A)--(B);
\draw[thick] (B)--(C);
\draw[thick] (C)--(D);
\draw[thick] (D)--(E);
\draw[thick] (E)--(F);
\draw[thick] (F)--(A);
\node at (0:0cm) {\scriptsize$3$};
\end{scope}
\begin{scope}[xshift=-1.5cm,yshift=6.09cm]
\node[draw,circle,inner sep=2.5pt,minimum size=2pt,fill=black] (A) at (0:1cm) {};
\node[draw,circle,inner sep=2.5pt,minimum size=2pt] (B) at (60:1cm) {};
\node[draw,circle,inner sep=2.5pt,minimum size=2pt,fill=black] (C) at (120:1cm) {};
\node[draw,circle,inner sep=2.5pt,minimum size=2pt] (D) at (180:1cm) {};
\node[draw,circle,inner sep=2.5pt,minimum size=2pt,fill=black] (E) at (240:1cm) {};
\node[draw,circle,inner sep=2.5pt,minimum size=2pt] (F) at (300:1cm) {};
\draw[thick] (A)--(B);
\draw[thick] (B)--(C);
\draw[thick] (C)--(D);
\draw[thick] (D)--(E);
\draw[thick] (E)--(F);
\draw[thick] (F)--(A);
\node at (0:0cm) {\scriptsize$4$};
\coordinate (1c) at (280:0.7cm);
\end{scope}


Above there is an example of how I programmed two adjacent hexagons. I programmed one and then I shifted the reference frame to have the second one below. With "\coordinate" I save a point so that in the end I can draw the red rectangle. Based on this way of programming, How can I add the blue arrows? There should be a way to put the arrows parallel to the line joining the two nodes, and then maybe with decorate I can add the number of >> that I need. Any suggestion? Thank you, I apologize if this is not the best way to draw this tiling but it is the most versatile for what I need to do, so I would like not to change it, but I am interested in how to add parallel lines joining (or pointing) to two nodes.

• This looks like the perfect use case for a loop here. But in order to do something like this I'd need to know what the numbers in the hexagon mean and how they are obtained Commented Mar 25, 2019 at 17:42
• Sure, there are many posts that draw a hexagonal lattice, like e.g. tex.stackexchange.com/a/6025/121799. I recommend you do a google picture search for site:tex.stackexchange.com hexagonal lattice tikz and look at promising posts. If there is something that you need to add, you have an arguably simpler starting point for your question.
– user121799
Commented Mar 25, 2019 at 17:55

Your code is far from optimal, so I'll not reproduce it here. I only show you how to add the blue arrow next to an edge, as you asked, by creating a style with arrows.

EDIT: I added also a closepath code to with arrows style in a way to be able to use it with regular polygon nodes (shown already in the @marmot's answer).

\documentclass[tikz,border=7pt]{standalone}
\usetikzlibrary{decorations.pathreplacing,calc,shapes.geometric}
\tikzstyle{with arrows}=[
postaction={decorate,
decoration={show path construction,
lineto code={
\draw [blue,-latex] ($(\tikzinputsegmentfirst)!1mm!45:(\tikzinputsegmentlast)$) -- ($(\tikzinputsegmentlast)!1mm!-45:(\tikzinputsegmentfirst)$);
},
closepath code={
\draw [blue,-latex] ($(\tikzinputsegmentfirst)!1mm!45:(\tikzinputsegmentlast)$) -- ($(\tikzinputsegmentlast)!1mm!-45:(\tikzinputsegmentfirst)$);
}
}
}
]
\begin{document}
\begin{tikzpicture}
\draw[with arrows] (0,0) -- (1,1) node[scale=2]{.} -- (2,0);
\node[regular polygon,regular polygon sides=6,minimum width=2cm,draw,with arrows] at (3,1) {1};
\end{tikzpicture}
\end{document}



• I know that the efficient was not the strong point of my code, I just wanted to have an easy way to add arrows to the edge and your macro solved my problem. Thanks! Commented Mar 26, 2019 at 7:36

It is not too difficult to draw such a thing in loops. pics may further help to avoid repetition. I did not understand your numbering scheme so you will have to modify evaluate=\Y as \Z using {int(mod(33-\Y-\X,5)+1)} to match your prescription.

\documentclass[tikz,border=3.14mm]{standalone}
\usetikzlibrary{shapes.geometric,calc}
\newcounter{hexi}
\begin{document}
\begin{tikzpicture}[pics/hexi/.style={code={\stepcounter{hexi}
\node[draw,regular polygon,regular polygon sides=6,minimum width=2cm]
(hexi-\number\value{hexi}) {#1};
\foreach \Corner in {1,...,6}
{\ifodd\Corner
\else
\fi}
}},bullet/.style={circle,fill,inner sep=0.5pt}]
%
\clip (0,1) rectangle (9.8,6.5);
% draw the hexagons
\path foreach \X in {1,...,6} {
foreach \Y [evaluate=\Y as \Z using {int(mod(33-\Y-\X,5)+1)}] in {1,...,4} { \ifodd\X
({\X*(1+cos(60))},{\Y*(2*sin(60))})
\else
({\X*(1+cos(60))},{\Y*(2*sin(60))-sin(60)})
\fi pic{hexi=\Z}}};
% draw the blue arrows
\foreach \X in {7,9,10,11,14}
{\foreach \Y [remember=\Y as \LastY (initially 6)]in {1,...,6}
{\draw[blue,-latex,shorten >=2pt,shorten <=2pt]
($(hexi-\X.corner \LastY)!0.1!(hexi-\X.center)$)
-- ($(hexi-\X.corner \Y)!0.1!(hexi-\X.center)$);}}
% draw the red contour
\draw[red] ([yshift=-0.3cm]hexi-3.center) node[bullet]{}
-- ([yshift=-0.3cm]hexi-6.center) node[bullet]{}
-- ([yshift=-0.3cm]hexi-18.center) node[bullet]{}
-- ([yshift=-0.3cm]hexi-16.center) node[bullet]{} -- cycle;
\end{tikzpicture}
\end{document}


• You are as good with tikz as wipet is with pdf specials! And that is saying a lot. Commented Mar 25, 2019 at 18:50
• @StevenB.Segletes Thanks a lot but I beg to disagree. I am not at all good at TikZ but most of the good users like Jake, percusse and cfr seem to be on vacation, or, as in Henri Menke's case not interested in such questions.
– user121799
Commented Mar 25, 2019 at 19:07
• Thanks, this is the most efficient and correct way to programme it. However, I use these hexagons also singularly and in different tilings so I like the idea of having them separated one from the other. Each piece of the hexagons (edges, vertices and labels) have a meaning. I was looking for a easy way to add the blue arrows to each edge and I think that the macro of @Kpym solved my problem. I feel obliged to give the correct answer to him. Thank you! Commented Mar 26, 2019 at 7:35
• @AlessandroMininno It would have been really helpful if you had specified that in the question.
– user121799
Commented Mar 26, 2019 at 13:09