Adding arrows to rectangles in TikZ

Question

Is it possible to decorate rectangles with arrows? I used:

\node [draw,rectangle,minimum width=4cm,minimum height=4cm](r){};

But then it is really difficult to line up an edge so that it's level with the edge of the rectangle, is there an easier way? I want it to look like:

enter image description here

Perhaps you can find some inspiration here http://tex.stackexchange.com/questions/172288/complex-dynamically-sized-tikz-diagram — Fredrik Pihl, Apr 21 '15 at 13:54
Welcome to TeX.SX!. When asking questions it is better to provide a full minimal working example (MWE) both in order to demonstrate what you are trying to do and to help others help you. The MWE should look like \documentclass...\begin{document}...\end{document}, it should compile and contain close to the minimal amount of code needed to explain/demonstrate what you are asking. This saves everyone time:) — , Apr 21 '15 at 13:56

score 4 · Answer 1 · 2015-04-21T14:17:34.347

Your rectangle is a node. Hence you can place an arrow shaped node at its anchors like south and east.

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{shapes.arrows}

\tikzset{
myarrow/.style={
  draw,thick,
  single arrow,
  text width=1cm,
  fill=white
  },
}


\begin{document}
 \begin{tikzpicture}
   \node [draw,rectangle,minimum size=4cm](r){};
   \node[myarrow,rotate=90] at (r.east){};
   \node[myarrow] at (r.south){};
 \end{tikzpicture}%
\end{document}

enter image description here

For modifying the shape of the arrow, you may refer to pgfmanual page 725, section 67.5, under shape single arrow.

Using the calc library you can also locate between anchors like ($(r.south west)!0.25!(r.south east)$) — John Kormylo, Apr 21 '15 at 16:01

score 3 · Answer 2 · edited Apr 13 '17 at 12:34

And here's a simple Metapost approach.

enter image description here

prologues := 3;
outputtemplate := "%j%c.eps";

ad_phi = 1/2;
ad_rho = 7/8;

% return the path of an arrow scaled to size "s" at time "t" on path "p"
vardef arrow_decor(expr s, t, p) = 
  save a; path a;
  a = ((1,0) -- (0,ad_rho) -- (0,ad_phi) -- (-1,ad_phi) 
      -- (-1,-ad_phi) -- (0,-ad_phi) -- (0,-ad_rho) -- cycle) 
      scaled 1/2 s
      rotated angle direction t of p 
      shifted point t of p;
  unfill a;
  a
  enddef;

beginfig(1);
path R; 
R = unitsquare xscaled 55 yscaled 34;
draw R; 
for t = 1/2 step 1 until 4:
  draw arrow_decor(8, t, R);
endfor
endfig;
end.

Adjust ad_rho and ad_phi to control the shape of the arrow. Or just change the definition of a in the macro to suit.

Adding arrows to rectangles in TikZ

2 Answers2