--- a
+++ b/inst/poisson_moments.m
@@ -0,0 +1,27 @@
+# Copyright (C) 2005  Michael Creel <michael.creel@uab.es>
+# 
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+# 
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ 
+# the form a user-written moment function should take
+
+function m = poisson_moments(theta, data, momentargs)
+	k = momentargs{1}; # use this so that data can hold dep, indeps, and instr
+	y = data(:,1);
+	x = data(:,2:k+1);
+	w = data(:, k+2:columns(data));
+	lambda = exp(x*theta);
+	e = y ./ lambda - 1;
+	m = dmult(e, w);
+endfunction