Xy-pic User's Guide

3.2 Extra entries outside the matrix

It is possible to put extra entries in your diagrams that are not part of any "entry" of the matrix created by & and \\. This is done with the excursion command

\save t \restore

where t should be a target in one of the formats described in sections 2.5-2.6. t can do any kind of typesetting desired, for example,

\xymatrix{
 A \ar@{-}[dr]
 &{}\save[]+<3cm,0cm>*\txt<8pc>{%
     This is a very big commentary
     but it does not otherwise affect
     the diagram.}
     \ar[l] \ar[d] \restore \\
 & B \ar@{-}[r] & C \ar@{-}[r] & D
}

will typeset

It illustrates how a "down" arrow does not necessarily have to point particularly straight down - in this case because it is based in the displaced pseudo entry.

 

Xy-pic User's Guide