Index: /issm/trunk/src/m/classes/constants.m
===================================================================
--- /issm/trunk/src/m/classes/constants.m	(revision 9599)
+++ /issm/trunk/src/m/classes/constants.m	(revision 9599)
@@ -0,0 +1,48 @@
+%CONSTANTS class definition
+%
+%   Usage:
+%      constants=constants();
+
+classdef constants
+	properties (SetAccess=public) 
+		g                    = modelfield('default',0,'marshall',true,'format','Double');
+		yts                  = modelfield('default',0,'marshall',true,'format','Double');
+		referencetemperature = modelfield('default',0,'marshall',true,'format','Double');
+	end
+	methods
+		function obj = constants(varargin) % {{{
+			switch nargin
+				case 0
+					obj=setdefaultparameters(obj);
+				case 1
+					in=varargin{1};
+					if (isa(in,'numeric') & in==0),
+						% requesting templates do nothing
+					else
+						error('constructor not supported');
+					end 
+				otherwise
+					error('constructor not supported');
+			end
+		end % }}}
+		function obj = setdefaultparameters(obj) % {{{
+
+			%first, use the defaults provided by the properties definition above. 
+			fieldnames=fields(obj);
+			for i=1:length(fieldnames),
+				fieldname=fieldnames{i};
+				obj.(fieldname)=obj.(fieldname).default;
+			end
+
+			%acceleration due to gravity (m/s^2)
+			obj.g=9.81;
+
+			%converstion from year to seconds
+			obj.yts=365*24*3600;
+
+			%the reference temperature for enthalpy model (cf Aschwanden)
+			obj.referencetemperature=223.15;
+
+		end % }}}
+	end
+end