Index: /issm/trunk-jpl/src/m/classes/gia.py
===================================================================
--- /issm/trunk-jpl/src/m/classes/gia.py	(revision 14824)
+++ /issm/trunk-jpl/src/m/classes/gia.py	(revision 14824)
@@ -0,0 +1,67 @@
+from fielddisplay import fielddisplay
+from EnumDefinitions import *
+from checkfield import *
+from WriteData import *
+
+class gia(object):
+	"""
+	GIA class definition
+
+	   Usage:
+	      gia=gia();
+	"""
+
+	def __init__(self): # {{{
+		self.lithosphere_thickness         = float('NaN');
+		self.output_rates                  = 0;
+		self.cross_section_shape           = 0;
+	
+		#set defaults
+		self.setdefaultparameters()
+
+		#}}}
+	def __repr__(self): # {{{
+		
+		string='   gia solution parameters:' 
+		
+		string="%s\n%s"%(string,fielddisplay(self,'lithosphere_thickness','lithosphere thickness constraints (NaN means no constraint) [m]'))
+		string="%s\n%s"%(string,fielddisplay(self,'output_rates','1: deflection (w) [m], 2: rate of deflection (dw/dt) [mm/yr]'))
+		string="%s\n%s"%(string,fielddisplay(self,'cross_section_shape',"1: square-edged, 2: elliptical-edged surface"))
+		return string
+		#}}}
+	def setdefaultparameters(self): # {{{
+
+		self.output_rates=1;  
+		self.cross_section_shape=1; 
+
+		return self
+	#}}}
+	def checkconsistency(self,md,solution,analyses):    # {{{
+
+		# Early return 
+		if not ismember(GiaAnalysisEnum(), analyses):
+			return md 
+		
+		md = checkfield(md,'gia.lithosphere_thickness','NaN',1,'size',[md.mesh.numberofvertices 1],'>',0)
+		md = checkfield(md,'gia.output_rates','numel',[1],'values',[1,2])
+		md = checkfield(md,'gia.cross_section_shape','numel',[1],'values',[1,2])
+
+		#be sure that if we are running a prognostic ice flow model coupled with gia, that thickness forcings 
+		#are not provided into the future.
+		if md.transient.isprognostic:
+			thickness=md.geometry.thickness 
+			#figure out if thickness is a transient forcing: 
+			s=size(thickness)
+			if s(1)>=md.mesh.numberofvertices:
+				#recover the furthest time "in time": 
+				time=thickness(end,end)
+				if not time==md.timestepping.start_time:
+					raise RunetimeError("if isprognostic is on, transient thickness forcing for the gia model should not be provided in the future. Synchronize your start_time to correspond to the most recent transient thickness forcing timestep")
+
+		return md
+	# }}}
+	def marshall(self,fid):    # {{{
+		WriteData(fid,'data',self.lithosphere_thickness,'format','DoubleMat','mattype',1,'enum',GiaLithosphereThicknessEnum());
+		WriteData(fid,'object',self,'fieldname','output_rates','format','Integer');
+		WriteData(fid,'object',self,'fieldname','cross_section_shape','format','Integer');
+	# }}}