--- a
+++ b/nls_estimate.m
@@ -0,0 +1,71 @@
+## 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
+
+# usage: 
+# [theta, obj_value, conv, iters] = nls_estimate(theta, data, model, modelargs, control, nslaves) 
+#
+# inputs:
+# theta: column vector of model parameters
+# data: data matrix
+# model: name of function that computes log-likelihood
+# modelargs: (cell) additional inputs needed by model. May be empty ("")
+# control: (optional) BFGS or SA controls (see bfgsmin and samin). May be empty (""). 
+# nslaves: (optional) number of slaves if executed in parallel (requires MPITB)
+#
+# outputs:
+# theta: NLS estimated value of parameters
+# obj_value: the value of the sum of squared errors at NLS estimate
+# conv: return code from bfgsmin (1 means success, see bfgsmin for details)
+# iters: number of BFGS iteration used
+#
+# please see nls_example.m for examples of how to use this
+function [theta, obj_value, convergence, iters] = nls_estimate(theta, data, model, modelargs, control, nslaves)
+
+	if nargin < 3
+		error("nls_estimate: 3 arguments required");
+	endif
+
+	if nargin < 4 modelargs = {}; endif # create placeholder if not used
+	if !iscell(modelargs) modelargs = {}; endif # default controls if receive placeholder
+	if nargin < 5 control = {Inf,0,1,1}; endif # default controls and method
+	if !iscell(control) control = {Inf,0,1,1}; endif # default controls if receive placeholder
+	if nargin < 6 nslaves = 0; endif
+
+	if nslaves > 0
+		global NSLAVES PARALLEL NEWORLD TAG
+		LAM_Init(nslaves);
+		# Send the data to all nodes
+		NumCmds_Send({"data", "model", "modelargs"}, {data, model, modelargs});
+	endif
+
+	# bfgs or sa?
+	if (size(control,1)*size(control,2) == 0) # use default bfgs if no control
+		control = {Inf,0,1,1};	
+	  method = "bfgs";
+	elseif (size(control,1)*size(control,2) < 11)
+		method = "bfgs";
+	else method = "sa";	
+	endif
+	
+	if strcmp(method, "bfgs")
+	  [theta, obj_value, convergence, iters] = bfgsmin("nls_obj", {theta, data, model, modelargs, nslaves}, control);
+	elseif strcmp(method, "sa") 	
+	  [theta, obj_value, convergence] = samin("nls_obj", {theta, data, model, modelargs, nslaves}, control);
+	endif	
+	
+	# cleanup	
+	if nslaves > 0 LAM_Finalize; endif
+endfunction