--- a/pylearn/io/amat.py	Thu Jan 15 22:21:04 2009 -0500
+++ b/pylearn/io/amat.py	Thu Jan 15 22:21:35 2009 -0500
@@ -1,4 +1,22 @@
-"""load PLearn AMat files"""
+"""load PLearn AMat files
+
+
+An AMat file is an ascii format for dense matrices.
+
+The format is not precisely defined, so I'll describe here a single recipe for making a valid
+file.
+
+.. code-block:: text
+    
+    #size: <rows> <cols>
+    #sizes: <input cols> <target cols> <weight cols> <extra cols 0> <extra cols 1> <extra cols ...>
+    number number number ....
+    number number number ....
+
+
+Tabs and spaces are both valid delimiters.  Newlines separate consecutive rows.
+
+"""
 
 import sys, numpy, array