# Better arrowheads in commutative diagrams

The Fourier package gives a different look for the arrowheads, which looks nice to me. I also want to use this arrowhead in the commutative diagrams. I have tried Taylor's diagrams package, xy-matrix, but the arrowheads they produce is not the type I want. The best one is the Stealth style arrowhead from tikz. Since I only need simple diagrams, I really don't want to be tortured by tikz complicated syntax. Is it possible to transplant this Stealth style to diagrams or xy-matrix?

TikZ's syntax is complicated because it's powerful. You may only want a simple diagram now, but later on, you'll hit the edge of what's possible with xy. I'd recommend learning the basics of TikZ, the effort will repay itself as soon as you want to draw anything complicated.

And anyway, TikZ syntax isn't that complicated for simple diagrams:

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{positioning}
\begin{document}
\begin{tikzpicture}
% Tell it where the nodes are
\node (A) {$A$};
\node (B) [below=of A] {$B$};
\node (C) [right=of A] {$C$};
\node (D) [right=of B] {$D$};
% Tell it what arrows to draw
\draw[-stealth] (A)-- node[left] {\small $f$} (B);
\draw[-stealth] (B)-- node [below] {\small $g$} (D);
\draw[-stealth] (A)-- node [above] {\small $h$} (C);
\draw[-stealth] (C)-- node [right] {\small $k$} (D);
\end{tikzpicture}
\end{document}


And you can make things easier by specifying at the start that all paths should have the [-stealth] decoration and so on...

• And if you prefer the matrix based xy approach, you can do that with tikz too... Jun 23, 2011 at 11:52

With \usepackage[tips]{xy}, you can try \SelectTips{cm}{10}.

Where cmstand for computer modern and 10 for the font size. The possible variations are eu(for Euler), lu (for Lucida) and xy. For the size, you only have — according to the manual — the choice between 10, 11 or 12.

But you can do even more and define new type style, for example :

\newdir{|>}{*{\alpha}}
\xymatrix{
A \ar@{|>} [r] & B }


gives you something like that : A –α B.

For more reference, see the xyguide sections 2.2 and 2.9