Xy-pic User's Guide

1.2 Entries

A diagram is created by the command

\xymatrix{ ... }

where the "..." should be replaced by entries to be aligned in rows and columns where

• entries in a row are separated by & and
• entire rows are separated by \\.

For example,

was typeset by

\xymatrix{
  A &*+[F]{\sum_{i=n}^m {i^2}} \\
    & {\bullet} & D \ar[ul]     }

Notice the following:

• entries are typeset as mathematics (using "text style"); entries should not start with a macro (as illustrated by the use of {} around \bullet.
• all entries are centered,
• the separation between rows and columns is usually quite large in a diagram,
• empty entries at the end of rows may be omitted,
• "Xy-decorations" (here \ar[ul]) in entries allow drawing of arrows and such relative to the entries without changing the overall layout, and
• "Xy-modifiers" (here *+[F]) first in entries allow changing the format and shape in many ways.

 

Xy-pic User's Guide