# Separate chapters, each with individual preface, included in same document

I have a document I want to split up into individual sections. I'd like each individual section to be independently compilable, but of course I also need the whole document to compile.

The trouble is, each of my individual sections requires a large preface (\usepackage calls, command definitions, etc.) that I am including with either \input or \include. The preface includes the \documentclass command, so I end up getting ! LaTeX Error: Can be used only in preamble. if I try to compile the whole document.

I'm already using \usepackage{subfiles}, but it doesn't seem to solve the problem.

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The best package for this is the standalone package and class. It works great for me. I you might want to collect all your packages and preamble into a separate file so that this file can be included both in the main document and the sub documents. There are numerous examples on this site. –  Peter Grill Nov 12 '12 at 20:28
@PeterGrill make that an answer, it works –  keflavich Nov 13 '12 at 0:38