# [Xy-pic] Vertical alignment in xymatrix

Lengyel, Florian FLENGYEL at gc.cuny.edu
Wed Mar 5 15:14:04 CET 2003

Hi, Michael and others!

Consider these lines for solutions to mentioned problems.

Entrymodifiers is a weird thing --- i faild to apply a modifier to
a single cell later.  But it aligns the arrow in the axis (actually,
shifts the entries).

@!R0 at the beginning of \xymatrix guarantees the fixed \xymatrixrowsep
distance between entries' centers, thus you can move it up by
the same amount.

Actually, i made no tests of the latter, just guessed.

As for punctuation, i use to put it in \rlap{} in the last cell.

\documentclass[12pt]{book}
\usepackage[matrix,arrow]{xy}
\entrymodifiers={+!!<0pt,\fontdimen22\textfont2>}
\xymatrixrowsep={3pc}
\xymatrixcolsep={3pc}

\begin{document}
This is a test \raisebox{3pc}{$\xymatrix@!R0{& C \\ A_1^1 \ar[r]\ar[ur] & B \ar[u]}$}.
\end{document}

I can offer no better thanks for this than to use it in a project I'm
working on; for example:

\documentclass[12pt]{book}
\usepackage[all]{xy}
\usepackage{amsfonts}
% etc
\entrymodifiers={+!!<0pt,\fontdimen22\textfont2>}
\xymatrixrowsep={3pc}
\xymatrixcolsep={3pc}

\begin{document}

Examples of finite free categories are the discrete categories
$n=\{0,\ldots,n-1\}$ and the ordered categories
$\mathbf{n}=\{\xymatrix{0\ar[r]&1\ar[r]&\cdots\ar[r]&n-1}\}$ for
$n\ge 0$, as well as the subcategories
$\underline{\Lambda}=% \left(\raisebox{1.9pc}{\xymatrix@!R0{& (0,0)\ar[dl]\ar[dr] & \\ % (1,0) & & (0,1) % }}\right),\ \ {\underline{\Lambda}}^{\mathrm{op}}=% \left(\raisebox{1.9pc}{ \xymatrix@!R0{(1,0)\ar[dr] & & (0,1)\ar[dl]\\ & (1,1)}}\right)$
of $\mathbf{2}\times\mathbf{2}$, which is itself not free.

\end{document}

FL