# Copyright (C) 2003,2004  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, see <http://www.gnu.org/licenses/>.

# Unscales parameters that were estimated using scaled data
# primarily for use by BFGS
function [theta_us, vartheta_us] = unscale_parameters(theta, vartheta, scalecoefs);
	k = rows(theta);
	A = nth(scalecoefs, 1);
	b = nth(scalecoefs, 2);
	
	kk = rows(b);
	B = zeros(kk-1,kk);
	B = [b'; B];
	
	C = A + B;
	
	# allow for parameters that aren't associated with x
	if (k > kk)
		D = zeros(kk, k - kk);
		C = [C, D; D', eye(k - kk)];
	endif;	
	
	
	
	theta_us = C*theta;
	vartheta_us = C * vartheta * C';
endfunction
