Xy-pic User's Guide

## 1.7 Speeding up typesetting

One thing that you will notice is that Xy-pic is sometimes slow in typesetting diagrams (this is to be expected considering the number of drawing operations performed as reflected by the number last in each `xymatrix` message). If you followed the rule of starting all entries with a (nonexpandable) character or `{` then you can insert the declaration

`\CompileMatrices`

in the preamble of your document: this will create temporary files containing compiled versions of each matrix that can be loaded very quickly; they are automatically recreated when a matrix is changed.

If this causes some diagrams to not work, then such compilation can be explicitly switched off by using `\xymatrixnocompile` in place of `\xymatrix`. Compilation can be switched off completely with `\NoCompileMatrices` (which respects TeX grouping as does `\CompileMatrices`, by the way).

And if you are still not satisfied with the speed then you can add the following:

`\OnlyOutlines`

which will omit all compiled pictures; the additional command `\ShowOutlines` will add a dotted rectangle outlining the size of the picture.

Xy-pic User's Guide