too much spacing in xymatrix

Question

I am using xypic package and I wrote the following xymatrix

  \[ 
  \xymatrix{ 
  x       \ar@(ur,dr)[]|{a} \\
  |         \\
  y       \ar@(ur,dr)[]|{b}\\ 
  |          \\  
  z        \ar@(ur,dr)[]|{c}  
   } 
  \] 

but the spacing on the output pdf file is pretty bad (there is too much gap/spacing between the rows). I spent some time modifying as in 3.3 Spacing and rotation [page 9] from this link http://www-bcf.usc.edu/~cautis/tools/xypic.pdf but that link is not helping.

Is there a way to make the gap between the rows smaller?

Answer 1

You can regulate the interrow spacing with @R; for example the following code shortens it by 2pc (24pt, but it's customary to reason in terms of picas).

\documentclass{article}
\usepackage[all,cmtip]{xy}
\begin{document}
\[
\xymatrix@R-2pc{
 x \ar@(ur,dr)[]|{a} \\
 |                   \\
 y \ar@(ur,dr)[]|{b} \\
 |                   \\
 z \ar@(ur,dr)[]|{c}
}
\]
\end{document}

A different approach is to use tipless arrows, again shortening the space between rows:

\documentclass{article}
\usepackage[all,cmtip]{xy}
\begin{document}
\[
\xymatrix@R-1pc{
 x \ar@(ur,dr)[]|{a} \ar@{-}[d] \\
 y \ar@(ur,dr)[]|{b} \ar@{-}[d] \\
 z \ar@(ur,dr)[]|{c}
}
\]
\end{document}