Index: /issm/trunk-jpl/src/py3/classes/SMBcomponents.py
===================================================================
--- /issm/trunk-jpl/src/py3/classes/SMBcomponents.py	(revision 19897)
+++ /issm/trunk-jpl/src/py3/classes/SMBcomponents.py	(revision 19898)
@@ -56,20 +56,20 @@
 
 		if MasstransportAnalysisEnum() in analyses:
-			md = checkfield(md,'fieldname','smb.accumulation','timeseries',1,'NaN',1)
+			md = checkfield(md,'fieldname','smb.accumulation','timeseries',1,'NaN',1,'Inf',1)
 
 		if BalancethicknessAnalysisEnum() in analyses:
-			md = checkfield(md,'fieldname','smb.accumulation','size',[md.mesh.numberofvertices],'NaN',1)
+			md = checkfield(md,'fieldname','smb.accumulation','size',[md.mesh.numberofvertices],'NaN',1,'Inf',1)
 
 		if MasstransportAnalysisEnum() in analyses:
-			md = checkfield(md,'fieldname','smb.runoff','timeseries',1,'NaN',1)
+			md = checkfield(md,'fieldname','smb.runoff','timeseries',1,'NaN',1,'Inf',1)
 
 		if BalancethicknessAnalysisEnum() in analyses:
-			md = checkfield(md,'fieldname','smb.runoff','size',[md.mesh.numberofvertices],'NaN',1)
+			md = checkfield(md,'fieldname','smb.runoff','size',[md.mesh.numberofvertices],'NaN',1,'Inf',1)
 
 		if MasstransportAnalysisEnum() in analyses:
-			md = checkfield(md,'fieldname','smb.evaporation','timeseries',1,'NaN',1)
+			md = checkfield(md,'fieldname','smb.evaporation','timeseries',1,'NaN',1,'Inf',1)
 
 		if BalancethicknessAnalysisEnum() in analyses:
-			md = checkfield(md,'fieldname','smb.evaporation','size',[md.mesh.numberofvertices],'NaN',1)
+			md = checkfield(md,'fieldname','smb.evaporation','size',[md.mesh.numberofvertices],'NaN',1,'Inf',1)
 		
 		md = checkfield(md,'fieldname','masstransport.requested_outputs','stringrow',1)
Index: /issm/trunk-jpl/src/py3/classes/SMBd18opdd.py
===================================================================
--- /issm/trunk-jpl/src/py3/classes/SMBd18opdd.py	(revision 19897)
+++ /issm/trunk-jpl/src/py3/classes/SMBd18opdd.py	(revision 19898)
@@ -91,13 +91,13 @@
 		if MasstransportAnalysisEnum() in analyses:
 			md = checkfield(md,'fieldname','smb.desfac','<=',1,'numel',[1])
-			md = checkfield(md,'fieldname','smb.s0p','>=',0,'NaN',1,'size',[md.mesh.numberofvertices,1])
-			md = checkfield(md,'fieldname','smb.s0t','>=',0,'NaN',1,'size',[md.mesh.numberofvertices,1])
+			md = checkfield(md,'fieldname','smb.s0p','>=',0,'NaN',1,'Inf',1,'size',[md.mesh.numberofvertices,1])
+			md = checkfield(md,'fieldname','smb.s0t','>=',0,'NaN',1,'Inf',1,'size',[md.mesh.numberofvertices,1])
 			md = checkfield(md,'fieldname','smb.rlaps','>=',0,'numel',[1])
 			md = checkfield(md,'fieldname','smb.rlapslgm','>=',0,'numel',[1])
 
 			if self.isd18opd:
-				md = checkfield(md,'fieldname','smb.temperatures_presentday','size',[md.mesh.numberofvertices+1,12],'NaN',1,'timeseries',1)
-				md = checkfield(md,'fieldname','smb.precipitations_presentday','size',[md.mesh.numberofvertices+1,12],'NaN',1,'timeseries',1)
-				md = checkfield(md,'fieldname','smb.delta18o','NaN',1,'size',[2,numpy.nan],'singletimeseries',1)
+				md = checkfield(md,'fieldname','smb.temperatures_presentday','size',[md.mesh.numberofvertices+1,12],'NaN',1,'Inf',1,'timeseries',1)
+				md = checkfield(md,'fieldname','smb.precipitations_presentday','size',[md.mesh.numberofvertices+1,12],'NaN',1,'Inf',1,'timeseries',1)
+				md = checkfield(md,'fieldname','smb.delta18o','NaN',1,'Inf',1,'size',[2,numpy.nan],'singletimeseries',1)
 				md = checkfield(md,'fieldname','smb.dpermil','>=',0,'numel',[1])
 		
Index: /issm/trunk-jpl/src/py3/classes/SMBforcing.py
===================================================================
--- /issm/trunk-jpl/src/py3/classes/SMBforcing.py	(revision 19897)
+++ /issm/trunk-jpl/src/py3/classes/SMBforcing.py	(revision 19898)
@@ -43,8 +43,8 @@
 
 		if MasstransportAnalysisEnum() in analyses:
-			md = checkfield(md,'fieldname','smb.mass_balance','timeseries',1,'NaN',1)
+			md = checkfield(md,'fieldname','smb.mass_balance','timeseries',1,'NaN',1,'Inf',1)
 
 		if BalancethicknessAnalysisEnum() in analyses:
-			md = checkfield(md,'fieldname','smb.mass_balance','size',[md.mesh.numberofvertices],'NaN',1)
+			md = checkfield(md,'fieldname','smb.mass_balance','size',[md.mesh.numberofvertices],'NaN',1,'Inf',1)
 
 		md = checkfield(md,'fieldname','masstransport.requested_outputs','stringrow',1)
Index: /issm/trunk-jpl/src/py3/classes/SMBgradients.py
===================================================================
--- /issm/trunk-jpl/src/py3/classes/SMBgradients.py	(revision 19897)
+++ /issm/trunk-jpl/src/py3/classes/SMBgradients.py	(revision 19898)
@@ -49,8 +49,8 @@
 
 		if MasstransportAnalysisEnum() in analyses:
-			md = checkfield(md,'fieldname','smb.href','timeseries',1,'NaN',1)
-			md = checkfield(md,'fieldname','smb.smbref','timeseries',1,'NaN',1)
-			md = checkfield(md,'fieldname','smb.b_pos','timeseries',1,'NaN',1)
-			md = checkfield(md,'fieldname','smb.b_neg','timeseries',1,'NaN',1)
+			md = checkfield(md,'fieldname','smb.href','timeseries',1,'NaN',1,'Inf',1)
+			md = checkfield(md,'fieldname','smb.smbref','timeseries',1,'NaN',1,'Inf',1)
+			md = checkfield(md,'fieldname','smb.b_pos','timeseries',1,'NaN',1,'Inf',1)
+			md = checkfield(md,'fieldname','smb.b_neg','timeseries',1,'NaN',1,'Inf',1)
 
 		md = checkfield(md,'fieldname','masstransport.requested_outputs','stringrow',1)
Index: /issm/trunk-jpl/src/py3/classes/SMBmeltcomponents.py
===================================================================
--- /issm/trunk-jpl/src/py3/classes/SMBmeltcomponents.py	(revision 19897)
+++ /issm/trunk-jpl/src/py3/classes/SMBmeltcomponents.py	(revision 19898)
@@ -62,26 +62,26 @@
 
 		if MasstransportAnalysisEnum() in analyses:
-			md = checkfield(md,'fieldname','smb.accumulation','timeseries',1,'NaN',1)
+			md = checkfield(md,'fieldname','smb.accumulation','timeseries',1,'NaN',1,'Inf',1)
 
 		if BalancethicknessAnalysisEnum() in analyses:
-			md = checkfield(md,'fieldname','smb.accumulation','size',[md.mesh.numberofvertices],'NaN',1)
+			md = checkfield(md,'fieldname','smb.accumulation','size',[md.mesh.numberofvertices],'NaN',1,'Inf',1)
 
 		if MasstransportAnalysisEnum() in analyses:
-			md = checkfield(md,'fieldname','smb.melt','timeseries',1,'NaN',1)
+			md = checkfield(md,'fieldname','smb.melt','timeseries',1,'NaN',1,'Inf',1)
 
 		if BalancethicknessAnalysisEnum() in analyses:
-			md = checkfield(md,'fieldname','smb.melt','size',[md.mesh.numberofvertices],'NaN',1)
+			md = checkfield(md,'fieldname','smb.melt','size',[md.mesh.numberofvertices],'NaN',1,'Inf',1)
 
 		if MasstransportAnalysisEnum() in analyses:
-			md = checkfield(md,'fieldname','smb.refreeze','timeseries',1,'NaN',1)
+			md = checkfield(md,'fieldname','smb.refreeze','timeseries',1,'NaN',1,'Inf',1)
 
 		if BalancethicknessAnalysisEnum() in analyses:
-			md = checkfield(md,'fieldname','smb.refreeze','size',[md.mesh.numberofvertices],'NaN',1)
+			md = checkfield(md,'fieldname','smb.refreeze','size',[md.mesh.numberofvertices],'NaN',1,'Inf',1)
 
 		if MasstransportAnalysisEnum() in analyses:
-			md = checkfield(md,'fieldname','smb.evaporation','timeseries',1,'NaN',1)
+			md = checkfield(md,'fieldname','smb.evaporation','timeseries',1,'NaN',1,'Inf',1)
 
 		if BalancethicknessAnalysisEnum() in analyses:
-			md = checkfield(md,'fieldname','smb.evaporation','size',[md.mesh.numberofvertices],'NaN',1)
+			md = checkfield(md,'fieldname','smb.evaporation','size',[md.mesh.numberofvertices],'NaN',1,'Inf',1)
 
 		md = checkfield(md,'fieldname','masstransport.requested_outputs','stringrow',1)
Index: /issm/trunk-jpl/src/py3/classes/SMBpdd.py
===================================================================
--- /issm/trunk-jpl/src/py3/classes/SMBpdd.py	(revision 19897)
+++ /issm/trunk-jpl/src/py3/classes/SMBpdd.py	(revision 19898)
@@ -120,29 +120,29 @@
 		if MasstransportAnalysisEnum() in analyses:
 			md = checkfield(md,'fieldname','smb.desfac','<=',1,'numel',[1])
-			md = checkfield(md,'fieldname','smb.s0p','>=',0,'NaN',1,'size',[md.mesh.numberofvertices,1])
-			md = checkfield(md,'fieldname','smb.s0t','>=',0,'NaN',1,'size',[md.mesh.numberofvertices,1])
+			md = checkfield(md,'fieldname','smb.s0p','>=',0,'NaN',1,'Inf',1,'size',[md.mesh.numberofvertices,1])
+			md = checkfield(md,'fieldname','smb.s0t','>=',0,'NaN',1,'Inf',1,'size',[md.mesh.numberofvertices,1])
 			md = checkfield(md,'fieldname','smb.rlaps','>=',0,'numel',[1])
 			md = checkfield(md,'fieldname','smb.rlapslgm','>=',0,'numel',[1])
 
 			if (self.isdelta18o==0 and self.ismungsm==0):
-				md = checkfield(md,'fieldname','smb.monthlytemperatures','NaN',1,'timeseries',1)
-				md = checkfield(md,'fieldname','smb.precipitation','NaN',1,'timeseries',1)
+				md = checkfield(md,'fieldname','smb.monthlytemperatures','NaN',1,'Inf',1,'timeseries',1)
+				md = checkfield(md,'fieldname','smb.precipitation','NaN',1,'Inf',1,'timeseries',1)
 			elif self.isdelta18o:
-				md = checkfield(md,'fieldname','smb.delta18o','NaN',1,'size',[2,numpy.nan],'singletimeseries',1)
-				md = checkfield(md,'fieldname','smb.delta18o_surface','NaN',1,'size',[2,numpy.nan],'singletimeseries',1)
-				md = checkfield(md,'fieldname','smb.temperatures_presentday','size',[md.mesh.numberofvertices+1,12],'NaN',1,'timeseries',1)
-				md = checkfield(md,'fieldname','smb.temperatures_lgm','size',[md.mesh.numberofvertices+1,12],'NaN',1,'timeseries',1)
-				md = checkfield(md,'fieldname','smb.precipitations_presentday','size',[md.mesh.numberofvertices+1,12],'NaN',1,'timeseries',1)
-				md = checkfield(md,'fieldname','smb.precipitations_lgm','size',[md.mesh.numberofvertices+1,12],'NaN',1,'timeseries',1)                                       
-				md = checkfield(md,'fieldname','smb.Tdiff','NaN',1,'size',[2,numpy.nan],'singletimeseries',1)
-				md = checkfield(md,'fieldname','smb.sealev','NaN',1,'size',[2,numpy.nan],'singletimeseries',1)
+				md = checkfield(md,'fieldname','smb.delta18o','NaN',1,'Inf',1,'size',[2,numpy.nan],'singletimeseries',1)
+				md = checkfield(md,'fieldname','smb.delta18o_surface','NaN',1,'Inf',1,'size',[2,numpy.nan],'singletimeseries',1)
+				md = checkfield(md,'fieldname','smb.temperatures_presentday','size',[md.mesh.numberofvertices+1,12],'NaN',1,'Inf',1,'timeseries',1)
+				md = checkfield(md,'fieldname','smb.temperatures_lgm','size',[md.mesh.numberofvertices+1,12],'NaN',1,'Inf',1,'timeseries',1)
+				md = checkfield(md,'fieldname','smb.precipitations_presentday','size',[md.mesh.numberofvertices+1,12],'NaN',1,'Inf',1,'timeseries',1)
+				md = checkfield(md,'fieldname','smb.precipitations_lgm','size',[md.mesh.numberofvertices+1,12],'NaN',1,'Inf',1,'timeseries',1)                                       
+				md = checkfield(md,'fieldname','smb.Tdiff','NaN',1,'Inf',1,'size',[2,numpy.nan],'singletimeseries',1)
+				md = checkfield(md,'fieldname','smb.sealev','NaN',1,'Inf',1,'size',[2,numpy.nan],'singletimeseries',1)
 			elif self.ismungsm:
-				md = checkfield(md,'fieldname','smb.temperatures_presentday','size',[md.mesh.numberofvertices+1,12],'NaN',1,'timeseries',1)
-				md = checkfield(md,'fieldname','smb.temperatures_lgm','size',[md.mesh.numberofvertices+1,12],'NaN',1,'timeseries',1)
-				md = checkfield(md,'fieldname','smb.precipitations_presentday','size',[md.mesh.numberofvertices+1,12],'NaN',1,'timeseries',1)
-				md = checkfield(md,'fieldname','smb.precipitations_lgm','size',[md.mesh.numberofvertices+1,12],'NaN',1,'timeseries',1)                                       
-				md = checkfield(md,'fieldname','smb.Pfac','NaN',1,'size',[2,numpy.nan],'singletimeseries',1)
-				md = checkfield(md,'fieldname','smb.Tdiff','NaN',1,'size',[2,numpy.nan],'singletimeseries',1)
-				md = checkfield(md,'fieldname','smb.sealev','NaN',1,'size',[2,numpy.nan],'singletimeseries',1)
+				md = checkfield(md,'fieldname','smb.temperatures_presentday','size',[md.mesh.numberofvertices+1,12],'NaN',1,'Inf',1,'timeseries',1)
+				md = checkfield(md,'fieldname','smb.temperatures_lgm','size',[md.mesh.numberofvertices+1,12],'NaN',1,'Inf',1,'timeseries',1)
+				md = checkfield(md,'fieldname','smb.precipitations_presentday','size',[md.mesh.numberofvertices+1,12],'NaN',1,'Inf',1,'timeseries',1)
+				md = checkfield(md,'fieldname','smb.precipitations_lgm','size',[md.mesh.numberofvertices+1,12],'NaN',1,'Inf',1,'timeseries',1)                                       
+				md = checkfield(md,'fieldname','smb.Pfac','NaN',1,'Inf',1,'size',[2,numpy.nan],'singletimeseries',1)
+				md = checkfield(md,'fieldname','smb.Tdiff','NaN',1,'Inf',1,'size',[2,numpy.nan],'singletimeseries',1)
+				md = checkfield(md,'fieldname','smb.sealev','NaN',1,'Inf',1,'size',[2,numpy.nan],'singletimeseries',1)
 
 		md = checkfield(md,'fieldname','masstransport.requested_outputs','stringrow',1)
Index: /issm/trunk-jpl/src/py3/classes/balancethickness.py
===================================================================
--- /issm/trunk-jpl/src/py3/classes/balancethickness.py	(revision 19897)
+++ /issm/trunk-jpl/src/py3/classes/balancethickness.py	(revision 19898)
@@ -43,5 +43,5 @@
 
 		md = checkfield(md,'fieldname','balancethickness.spcthickness')
-		md = checkfield(md,'fieldname','balancethickness.thickening_rate','size',[md.mesh.numberofvertices],'NaN',1)
+		md = checkfield(md,'fieldname','balancethickness.thickening_rate','size',[md.mesh.numberofvertices],'NaN',1,'Inf',1)
 		md = checkfield(md,'fieldname','balancethickness.stabilization','size',[1],'values',[0,1,2,3])
 
Index: /issm/trunk-jpl/src/py3/classes/basalforcings.py
===================================================================
--- /issm/trunk-jpl/src/py3/classes/basalforcings.py	(revision 19897)
+++ /issm/trunk-jpl/src/py3/classes/basalforcings.py	(revision 19898)
@@ -55,15 +55,15 @@
 
 		if MasstransportAnalysisEnum() in analyses and not (solution==TransientSolutionEnum() and not md.transient.ismasstransport):
-			md = checkfield(md,'fieldname','basalforcings.groundedice_melting_rate','NaN',1,'timeseries',1)
-			md = checkfield(md,'fieldname','basalforcings.floatingice_melting_rate','NaN',1,'timeseries',1)
+			md = checkfield(md,'fieldname','basalforcings.groundedice_melting_rate','NaN',1,'Inf',1,'timeseries',1)
+			md = checkfield(md,'fieldname','basalforcings.floatingice_melting_rate','NaN',1,'Inf',1,'timeseries',1)
 
 		if BalancethicknessAnalysisEnum() in analyses:
-			md = checkfield(md,'fieldname','basalforcings.groundedice_melting_rate','NaN',1,'size',[md.mesh.numberofvertices])
-			md = checkfield(md,'fieldname','basalforcings.floatingice_melting_rate','NaN',1,'size',[md.mesh.numberofvertices])
+			md = checkfield(md,'fieldname','basalforcings.groundedice_melting_rate','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices])
+			md = checkfield(md,'fieldname','basalforcings.floatingice_melting_rate','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices])
 
 		if ThermalAnalysisEnum() in analyses and not (solution==TransientSolutionEnum() and not md.transient.isthermal):
-			md = checkfield(md,'fieldname','basalforcings.groundedice_melting_rate','NaN',1,'timeseries',1)
-			md = checkfield(md,'fieldname','basalforcings.floatingice_melting_rate','NaN',1,'timeseries',1)
-			md = checkfield(md,'fieldname','basalforcings.geothermalflux','NaN',1,'timeseries',1,'>=',0)
+			md = checkfield(md,'fieldname','basalforcings.groundedice_melting_rate','NaN',1,'Inf',1,'timeseries',1)
+			md = checkfield(md,'fieldname','basalforcings.floatingice_melting_rate','NaN',1,'Inf',1,'timeseries',1)
+			md = checkfield(md,'fieldname','basalforcings.geothermalflux','NaN',1,'Inf',1,'timeseries',1,'>=',0)
 
 		return md
Index: /issm/trunk-jpl/src/py3/classes/calving.py
===================================================================
--- /issm/trunk-jpl/src/py3/classes/calving.py	(revision 19897)
+++ /issm/trunk-jpl/src/py3/classes/calving.py	(revision 19898)
@@ -55,6 +55,6 @@
 		md = checkfield(md,'fieldname','calving.spclevelset','timeseries',1)
 		md = checkfield(md,'fieldname','calving.stabilization','values',[0,1,2]);
-		md = checkfield(md,'fieldname','calving.calvingrate','>=',0,'timeseries',1,'NaN',1);
-		md = checkfield(md,'fieldname','calving.meltingrate','>=',0,'timeseries',1,'NaN',1);
+		md = checkfield(md,'fieldname','calving.calvingrate','>=',0,'timeseries',1,'NaN',1,'Inf',1);
+		md = checkfield(md,'fieldname','calving.meltingrate','>=',0,'timeseries',1,'NaN',1,'Inf',1);
 
 		return md
Index: /issm/trunk-jpl/src/py3/classes/calvinglevermann.py
===================================================================
--- /issm/trunk-jpl/src/py3/classes/calvinglevermann.py	(revision 19897)
+++ /issm/trunk-jpl/src/py3/classes/calvinglevermann.py	(revision 19898)
@@ -56,5 +56,5 @@
 		md = checkfield(md,'fieldname','calving.stabilization','values',[0,1,2]);
 		md = checkfield(md,'fieldname','calving.coeff','size',[md.mesh.numberofvertices],'>',0)
-		md = checkfield(md,'fieldname','calving.meltingrate','NaN',1,'size',[md.mesh.numberofvertices],'>=',0)
+		md = checkfield(md,'fieldname','calving.meltingrate','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices],'>=',0)
 		return md
 	# }}}
Index: /issm/trunk-jpl/src/py3/classes/friction.py
===================================================================
--- /issm/trunk-jpl/src/py3/classes/friction.py	(revision 19897)
+++ /issm/trunk-jpl/src/py3/classes/friction.py	(revision 19898)
@@ -45,7 +45,7 @@
 			return md
 
-		md = checkfield(md,'fieldname','friction.coefficient','timeseries',1,'NaN',1)
-		md = checkfield(md,'fieldname','friction.q','NaN',1,'size',[md.mesh.numberofelements])
-		md = checkfield(md,'fieldname','friction.p','NaN',1,'size',[md.mesh.numberofelements])
+		md = checkfield(md,'fieldname','friction.coefficient','timeseries',1,'NaN',1,'Inf',1)
+		md = checkfield(md,'fieldname','friction.q','NaN',1,'Inf',1,'size',[md.mesh.numberofelements])
+		md = checkfield(md,'fieldname','friction.p','NaN',1,'Inf',1,'size',[md.mesh.numberofelements])
 
 		return md
Index: /issm/trunk-jpl/src/py3/classes/frictioncoulomb.py
===================================================================
--- /issm/trunk-jpl/src/py3/classes/frictioncoulomb.py	(revision 19897)
+++ /issm/trunk-jpl/src/py3/classes/frictioncoulomb.py	(revision 19898)
@@ -48,8 +48,8 @@
 	    return md
 
-	md = checkfield(md,'fieldname','friction.coefficient','timeseries',1,'NaN',1)
-	md = checkfield(md,'fieldname','friction.coefficientcoulomb','timeseries',1,'NaN',1)
-	md = checkfield(md,'fieldname','friction.q','NaN',1,'size',[md.mesh.numberofelements])
-	md = checkfield(md,'fieldname','friction.p','NaN',1,'size',[md.mesh.numberofelements])
+	md = checkfield(md,'fieldname','friction.coefficient','timeseries',1,'NaN',1,'Inf',1)
+	md = checkfield(md,'fieldname','friction.coefficientcoulomb','timeseries',1,'NaN',1,'Inf',1)
+	md = checkfield(md,'fieldname','friction.q','NaN',1,'Inf',1,'size',[md.mesh.numberofelements])
+	md = checkfield(md,'fieldname','friction.p','NaN',1,'Inf',1,'size',[md.mesh.numberofelements])
 
 	return md
Index: /issm/trunk-jpl/src/py3/classes/frictionweertman.py
===================================================================
--- /issm/trunk-jpl/src/py3/classes/frictionweertman.py	(revision 19897)
+++ /issm/trunk-jpl/src/py3/classes/frictionweertman.py	(revision 19898)
@@ -37,6 +37,6 @@
 			return md
 
-		md = checkfield(md,'fieldname','friction.C','timeseries',1,'NaN',1)
-		md = checkfield(md,'fieldname','friction.m','NaN',1,'size',[md.mesh.numberofelements])
+		md = checkfield(md,'fieldname','friction.C','timeseries',1,'NaN',1,'Inf',1)
+		md = checkfield(md,'fieldname','friction.m','NaN',1,'Inf',1,'size',[md.mesh.numberofelements])
 
 		return md
Index: /issm/trunk-jpl/src/py3/classes/geometry.py
===================================================================
--- /issm/trunk-jpl/src/py3/classes/geometry.py	(revision 19897)
+++ /issm/trunk-jpl/src/py3/classes/geometry.py	(revision 19898)
@@ -46,11 +46,11 @@
 	def checkconsistency(self,md,solution,analyses):    # {{{
 
-		md = checkfield(md,'fieldname','geometry.surface'  ,'NaN',1,'size',[md.mesh.numberofvertices])
-		md = checkfield(md,'fieldname','geometry.base'      ,'NaN',1,'size',[md.mesh.numberofvertices])
-		md = checkfield(md,'fieldname','geometry.thickness','NaN',1,'size',[md.mesh.numberofvertices],'>',0,'timeseries',1)
+		md = checkfield(md,'fieldname','geometry.surface'  ,'NaN',1,'Inf',1,'size',[md.mesh.numberofvertices])
+		md = checkfield(md,'fieldname','geometry.base'      ,'NaN',1,'Inf',1,'size',[md.mesh.numberofvertices])
+		md = checkfield(md,'fieldname','geometry.thickness','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices],'>',0,'timeseries',1)
 		if any(abs(self.thickness-self.surface+self.base)>10**-9):
 			md.checkmessage("equality thickness=surface-base violated")
 		if solution==TransientSolutionEnum() and md.transient.isgroundingline:
-			md = checkfield(md,'fieldname','geometry.bed','NaN',1,'size',[md.mesh.numberofvertices])
+			md = checkfield(md,'fieldname','geometry.bed','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices])
 
 		return md
Index: /issm/trunk-jpl/src/py3/classes/gia.py
===================================================================
--- /issm/trunk-jpl/src/py3/classes/gia.py	(revision 19897)
+++ /issm/trunk-jpl/src/py3/classes/gia.py	(revision 19898)
@@ -48,6 +48,6 @@
 			return md 
 		
-		md = checkfield(md,'fieldname','gia.mantle_viscosity','NaN',1,'size',[md.mesh.numberofvertices,1],'>',0)
-		md = checkfield(md,'fieldname','gia.lithosphere_thickness','NaN',1,'size',[md.mesh.numberofvertices,1],'>',0)
+		md = checkfield(md,'fieldname','gia.mantle_viscosity','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices,1],'>',0)
+		md = checkfield(md,'fieldname','gia.lithosphere_thickness','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices,1],'>',0)
 		md = checkfield(md,'fieldname','gia.cross_section_shape','numel',[1],'values',[1,2])
 
Index: /issm/trunk-jpl/src/py3/classes/hydrologydc.py
===================================================================
--- /issm/trunk-jpl/src/py3/classes/hydrologydc.py	(revision 19897)
+++ /issm/trunk-jpl/src/py3/classes/hydrologydc.py	(revision 19898)
@@ -163,5 +163,5 @@
 			md = checkfield(md,'fieldname','hydrology.leakage_factor','>',0.,'numel',[1])
 
-		md = checkfield(md,'fieldname','hydrology.basal_moulin_input','NaN',1,'timeseries',1)
+		md = checkfield(md,'fieldname','hydrology.basal_moulin_input','NaN',1,'Inf',1,'timeseries',1)
 		md = checkfield(md,'fieldname','hydrology.spcsediment_head','timeseries',1)
 		md = checkfield(md,'fieldname','hydrology.sediment_compressibility','>',0.,'numel',[1])
Index: /issm/trunk-jpl/src/py3/classes/initialization.py
===================================================================
--- /issm/trunk-jpl/src/py3/classes/initialization.py	(revision 19897)
+++ /issm/trunk-jpl/src/py3/classes/initialization.py	(revision 19898)
@@ -71,12 +71,12 @@
 		if StressbalanceAnalysisEnum() in analyses:
 			if not numpy.any(numpy.logical_or(numpy.isnan(md.initialization.vx),numpy.isnan(md.initialization.vy))):
-				md = checkfield(md,'fieldname','initialization.vx','NaN',1,'size',[md.mesh.numberofvertices])
-				md = checkfield(md,'fieldname','initialization.vy','NaN',1,'size',[md.mesh.numberofvertices])
+				md = checkfield(md,'fieldname','initialization.vx','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices])
+				md = checkfield(md,'fieldname','initialization.vy','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices])
 		if MasstransportAnalysisEnum() in analyses:
-			md = checkfield(md,'fieldname','initialization.vx','NaN',1,'size',[md.mesh.numberofvertices])
-			md = checkfield(md,'fieldname','initialization.vy','NaN',1,'size',[md.mesh.numberofvertices])
+			md = checkfield(md,'fieldname','initialization.vx','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices])
+			md = checkfield(md,'fieldname','initialization.vy','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices])
 		if BalancethicknessAnalysisEnum() in analyses:
-			md = checkfield(md,'fieldname','initialization.vx','NaN',1,'size',[md.mesh.numberofvertices])
-			md = checkfield(md,'fieldname','initialization.vy','NaN',1,'size',[md.mesh.numberofvertices])
+			md = checkfield(md,'fieldname','initialization.vx','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices])
+			md = checkfield(md,'fieldname','initialization.vy','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices])
 			#Triangle with zero velocity
 			if numpy.any(numpy.logical_and(numpy.sum(numpy.abs(md.initialization.vx[md.mesh.elements-1]),axis=1)==0,\
@@ -84,10 +84,10 @@
 				md.checkmessage("at least one triangle has all its vertices with a zero velocity")
 		if ThermalAnalysisEnum() in analyses:
-			md = checkfield(md,'fieldname','initialization.vx','NaN',1,'size',[md.mesh.numberofvertices])
-			md = checkfield(md,'fieldname','initialization.vy','NaN',1,'size',[md.mesh.numberofvertices])
-			md = checkfield(md,'fieldname','initialization.temperature','NaN',1,'size',[md.mesh.numberofvertices])
+			md = checkfield(md,'fieldname','initialization.vx','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices])
+			md = checkfield(md,'fieldname','initialization.vy','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices])
+			md = checkfield(md,'fieldname','initialization.temperature','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices])
 			if md.mesh.dimension()==3:
-				md = checkfield(md,'fieldname','initialization.vz','NaN',1,'size',[md.mesh.numberofvertices])
-			md = checkfield(md,'fieldname','initialization.pressure','NaN',1,'size',[md.mesh.numberofvertices])
+				md = checkfield(md,'fieldname','initialization.vz','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices])
+			md = checkfield(md,'fieldname','initialization.pressure','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices])
 			if (EnthalpyAnalysisEnum() in analyses and md.thermal.isenthalpy):
 				md = checkfield(md,'fieldname','initialization.waterfraction','>=',0,'size',[md.mesh.numberofvertices])
@@ -95,13 +95,13 @@
 		if HydrologyShreveAnalysisEnum() in analyses:
 			if hasattr(md.hydrology,'hydrologyshreve'):
-				md = checkfield(md,'fieldname','initialization.watercolumn','NaN',1,'size',[md.mesh.numberofvertices])
+				md = checkfield(md,'fieldname','initialization.watercolumn','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices])
 		if HydrologyDCInefficientAnalysisEnum() in analyses:
 			if hasattr(md.hydrology,'hydrologydc'):
-				md = checkfield(md,'fieldname','initialization.sediment_head','NaN',1,'size',[md.mesh.numberofvertices,1])
+				md = checkfield(md,'fieldname','initialization.sediment_head','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices,1])
 		if HydrologyDCEfficientAnalysisEnum() in analyses:
 			if hasattr(md.hydrology,'hydrologydc'):
 				if md.hydrology.isefficientlayer==1:
-					md = checkfield(md,'fieldname','initialization.epl_head','NaN',1,'size',[md.mesh.numberofvertices,1])
-					md = checkfield(md,'fieldname','initialization.epl_thickness','NaN',1,'size',[md.mesh.numberofvertices,1])
+					md = checkfield(md,'fieldname','initialization.epl_head','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices,1])
+					md = checkfield(md,'fieldname','initialization.epl_thickness','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices,1])
 
 		return md
Index: /issm/trunk-jpl/src/py3/classes/inversion.py
===================================================================
--- /issm/trunk-jpl/src/py3/classes/inversion.py	(revision 19897)
+++ /issm/trunk-jpl/src/py3/classes/inversion.py	(revision 19898)
@@ -151,8 +151,8 @@
 
 		if solution==BalancethicknessSolutionEnum():
-			md = checkfield(md,'fieldname','inversion.thickness_obs','size',[md.mesh.numberofvertices],'NaN',1)
+			md = checkfield(md,'fieldname','inversion.thickness_obs','size',[md.mesh.numberofvertices],'NaN',1,'Inf',1)
 		else:
-			md = checkfield(md,'fieldname','inversion.vx_obs','size',[md.mesh.numberofvertices],'NaN',1)
-			md = checkfield(md,'fieldname','inversion.vy_obs','size',[md.mesh.numberofvertices],'NaN',1)
+			md = checkfield(md,'fieldname','inversion.vx_obs','size',[md.mesh.numberofvertices],'NaN',1,'Inf',1)
+			md = checkfield(md,'fieldname','inversion.vy_obs','size',[md.mesh.numberofvertices],'NaN',1,'Inf',1)
 
 		return md
Index: /issm/trunk-jpl/src/py3/classes/linearbasalforcings.py
===================================================================
--- /issm/trunk-jpl/src/py3/classes/linearbasalforcings.py	(revision 19897)
+++ /issm/trunk-jpl/src/py3/classes/linearbasalforcings.py	(revision 19898)
@@ -69,5 +69,5 @@
 
 		if MasstransportAnalysisEnum() in analyses and not (solution==TransientSolutionEnum() and not md.transient.ismasstransport):
-			md = checkfield(md,'fieldname','basalforcings.groundedice_melting_rate','NaN',1,'timeseries',1)
+			md = checkfield(md,'fieldname','basalforcings.groundedice_melting_rate','NaN',1,'Inf',1,'timeseries',1)
 			md = checkfield(md,'fieldname','basalforcings.deepwater_melting_rate','>=',0);
 			md = checkfield(md,'fieldname','basalforcings.deepwater_elevation','<',md.basalforcings.upperwater_elevation);
@@ -75,5 +75,5 @@
 
 		if BalancethicknessAnalysisEnum() in analyses:
-			md = checkfield(md,'fieldname','basalforcings.groundedice_melting_rate','NaN',1,'size',[md.mesh.numberofvertices])
+			md = checkfield(md,'fieldname','basalforcings.groundedice_melting_rate','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices])
 			md = checkfield(md,'fieldname','basalforcings.deepwater_melting_rate','>=',0);
 			md = checkfield(md,'fieldname','basalforcings.deepwater_elevation','<',md.basalforcings.upperwater_elevation);
@@ -81,9 +81,9 @@
 
 		if ThermalAnalysisEnum() in analyses and not (solution==TransientSolutionEnum() and not md.transient.isthermal):
-			md = checkfield(md,'fieldname','basalforcings.groundedice_melting_rate','NaN',1,'timeseries',1)
+			md = checkfield(md,'fieldname','basalforcings.groundedice_melting_rate','NaN',1,'Inf',1,'timeseries',1)
 			md = checkfield(md,'fieldname','basalforcings.deepwater_melting_rate','>=',0);
 			md = checkfield(md,'fieldname','basalforcings.deepwater_elevation','<',md.basalforcings.upperwater_elevation);
 			md = checkfield(md,'fieldname','basalforcings.upperwater_elevation','<',0);
-			md = checkfield(md,'fieldname','basalforcings.geothermalflux','NaN',1,'timeseries',1,'>=',0)
+			md = checkfield(md,'fieldname','basalforcings.geothermalflux','NaN',1,'Inf',1,'timeseries',1,'>=',0)
 
 		return md
Index: /issm/trunk-jpl/src/py3/classes/m1qn3inversion.py
===================================================================
--- /issm/trunk-jpl/src/py3/classes/m1qn3inversion.py	(revision 19897)
+++ /issm/trunk-jpl/src/py3/classes/m1qn3inversion.py	(revision 19898)
@@ -145,5 +145,5 @@
 		md = checkfield(md,'fieldname','inversion.incomplete_adjoint','values',[0,1])
 		md = checkfield(md,'fieldname','inversion.control_parameters','cell',1,'values',supportedcontrols())
-		md = checkfield(md,'fieldname','inversion.control_scaling_factors','size',[num_controls],'>',0,'NaN',1)
+		md = checkfield(md,'fieldname','inversion.control_scaling_factors','size',[num_controls],'>',0,'NaN',1,'Inf',1)
 		md = checkfield(md,'fieldname','inversion.maxsteps','numel',[1],'>=',0)
 		md = checkfield(md,'fieldname','inversion.maxiter','numel',[1],'>=',0)
@@ -156,8 +156,8 @@
 
 		if solution==BalancethicknessSolutionEnum():
-			md = checkfield(md,'fieldname','inversion.thickness_obs','size',[md.mesh.numberofvertices],'NaN',1)
+			md = checkfield(md,'fieldname','inversion.thickness_obs','size',[md.mesh.numberofvertices],'NaN',1,'Inf',1)
 		else:
-			md = checkfield(md,'fieldname','inversion.vx_obs','size',[md.mesh.numberofvertices],'NaN',1)
-			md = checkfield(md,'fieldname','inversion.vy_obs','size',[md.mesh.numberofvertices],'NaN',1)
+			md = checkfield(md,'fieldname','inversion.vx_obs','size',[md.mesh.numberofvertices],'NaN',1,'Inf',1)
+			md = checkfield(md,'fieldname','inversion.vy_obs','size',[md.mesh.numberofvertices],'NaN',1,'Inf',1)
 
 		return md
Index: /issm/trunk-jpl/src/py3/classes/matice.py
===================================================================
--- /issm/trunk-jpl/src/py3/classes/matice.py	(revision 19897)
+++ /issm/trunk-jpl/src/py3/classes/matice.py	(revision 19898)
@@ -123,5 +123,5 @@
 		md = checkfield(md,'fieldname','materials.rho_freshwater','>',0)
 		md = checkfield(md,'fieldname','materials.mu_water','>',0)
-		md = checkfield(md,'fieldname','materials.rheology_B','>',0,'timeseries',1,'NaN',1)
+		md = checkfield(md,'fieldname','materials.rheology_B','>',0,'timeseries',1,'NaN',1,'Inf',1)
 		md = checkfield(md,'fieldname','materials.rheology_n','>',0,'size',[md.mesh.numberofelements])
 		md = checkfield(md,'fieldname','materials.rheology_law','values',['None','Cuffey','Paterson','Arrhenius','LliboutryDuval'])
Index: /issm/trunk-jpl/src/py3/classes/mesh2d.py
===================================================================
--- /issm/trunk-jpl/src/py3/classes/mesh2d.py	(revision 19897)
+++ /issm/trunk-jpl/src/py3/classes/mesh2d.py	(revision 19898)
@@ -84,7 +84,7 @@
 	def checkconsistency(self,md,solution,analyses):    # {{{
 
-		md = checkfield(md,'fieldname','mesh.x','NaN',1,'size',[md.mesh.numberofvertices])
-		md = checkfield(md,'fieldname','mesh.y','NaN',1,'size',[md.mesh.numberofvertices])
-		md = checkfield(md,'fieldname','mesh.elements','NaN',1,'>',0,'values',numpy.arange(1,md.mesh.numberofvertices+1))
+		md = checkfield(md,'fieldname','mesh.x','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices])
+		md = checkfield(md,'fieldname','mesh.y','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices])
+		md = checkfield(md,'fieldname','mesh.elements','NaN',1,'Inf',1,'>',0,'values',numpy.arange(1,md.mesh.numberofvertices+1))
 		md = checkfield(md,'fieldname','mesh.elements','size',[md.mesh.numberofelements,3])
 #		if numpy.any(numpy.logical_not(m.ismember(numpy.arange(1,md.mesh.numberofvertices+1),md.mesh.elements))):
Index: /issm/trunk-jpl/src/py3/classes/mesh3dprisms.py
===================================================================
--- /issm/trunk-jpl/src/py3/classes/mesh3dprisms.py	(revision 19897)
+++ /issm/trunk-jpl/src/py3/classes/mesh3dprisms.py	(revision 19898)
@@ -106,8 +106,8 @@
 	def checkconsistency(self,md,solution,analyses):    # {{{
 
-		md = checkfield(md,'fieldname','mesh.x','NaN',1,'size',[md.mesh.numberofvertices])
-		md = checkfield(md,'fieldname','mesh.y','NaN',1,'size',[md.mesh.numberofvertices])
-		md = checkfield(md,'fieldname','mesh.z','NaN',1,'size',[md.mesh.numberofvertices])
-		md = checkfield(md,'fieldname','mesh.elements','NaN',1,'>',0,'values',numpy.arange(1,md.mesh.numberofvertices+1))
+		md = checkfield(md,'fieldname','mesh.x','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices])
+		md = checkfield(md,'fieldname','mesh.y','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices])
+		md = checkfield(md,'fieldname','mesh.z','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices])
+		md = checkfield(md,'fieldname','mesh.elements','NaN',1,'Inf',1,'>',0,'values',numpy.arange(1,md.mesh.numberofvertices+1))
 		md = checkfield(md,'fieldname','mesh.elements','size',[md.mesh.numberofelements,6])
 		if numpy.any(numpy.logical_not(m.ismember(numpy.arange(1,md.mesh.numberofvertices+1),md.mesh.elements))):
Index: /issm/trunk-jpl/src/py3/classes/mismipbasalforcings.py
===================================================================
--- /issm/trunk-jpl/src/py3/classes/mismipbasalforcings.py	(revision 19897)
+++ /issm/trunk-jpl/src/py3/classes/mismipbasalforcings.py	(revision 19898)
@@ -58,5 +58,5 @@
         if MasstransportAnalysisEnum() in analyses and not (solution==TransientSolutionEnum() and md.transient.ismasstransport==0):
 
-	    md = checkfield(md,'fieldname','basalforcings.groundedice_melting_rate','NaN',1,'timeseries',1)
+	    md = checkfield(md,'fieldname','basalforcings.groundedice_melting_rate','NaN',1,'Inf',1,'timeseries',1)
 	    md = checkfield(md,'fieldname','basalforcings.meltrate_factor','>=',0,'numel',[1])
 	    md = checkfield(md,'fieldname','basalforcings.threshold_thickness','>=',0,'numel',[1])
@@ -65,5 +65,5 @@
         if BalancethicknessAnalysisEnum() in analyses:
 
-	    md = checkfield(md,'fieldname','basalforcings.groundedice_melting_rate','NaN',1,'size',[md.mesh.numberofvertices])
+	    md = checkfield(md,'fieldname','basalforcings.groundedice_melting_rate','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices])
 	    md = checkfield(md,'fieldname','basalforcings.meltrate_factor','>=',0,'numel',[1])
 	    md = checkfield(md,'fieldname','basalforcings.threshold_thickness','>=',0,'numel',[1])
@@ -72,9 +72,9 @@
         if ThermalAnalysisEnum() in analyses and not (solution==TransientSolutionEnum() and md.transient.isthermal==0):
 
-	    md = checkfield(md,'fieldname','basalforcings.groundedice_melting_rate','NaN',1,'timeseries',1)
+	    md = checkfield(md,'fieldname','basalforcings.groundedice_melting_rate','NaN',1,'Inf',1,'timeseries',1)
 	    md = checkfield(md,'fieldname','basalforcings.meltrate_factor','>=',0,'numel',[1])
 	    md = checkfield(md,'fieldname','basalforcings.threshold_thickness','>=',0,'numel',[1])
 	    md = checkfield(md,'fieldname','basalforcings.upperdepth_melt','<=',0,'numel',[1])
-	    md = checkfield(md,'fieldname','basalforcings.geothermalflux','NaN',1,'timeseries',1,'>=',0)
+	    md = checkfield(md,'fieldname','basalforcings.geothermalflux','NaN',1,'Inf',1,'timeseries',1,'>=',0)
 	return md
     # }}}
Index: /issm/trunk-jpl/src/py3/classes/stressbalance.py
===================================================================
--- /issm/trunk-jpl/src/py3/classes/stressbalance.py	(revision 19897)
+++ /issm/trunk-jpl/src/py3/classes/stressbalance.py	(revision 19898)
@@ -141,6 +141,6 @@
 		md = checkfield(md,'fieldname','stressbalance.abstol','size',[1])
 		md = checkfield(md,'fieldname','stressbalance.isnewton','numel',[1],'values',[0,1,2])
-		md = checkfield(md,'fieldname','stressbalance.FSreconditioning','size',[1],'NaN',1)
-		md = checkfield(md,'fieldname','stressbalance.viscosity_overshoot','size',[1],'NaN',1)
+		md = checkfield(md,'fieldname','stressbalance.FSreconditioning','size',[1],'NaN',1,'Inf',1)
+		md = checkfield(md,'fieldname','stressbalance.viscosity_overshoot','size',[1],'NaN',1,'Inf',1)
 		md = checkfield(md,'fieldname','stressbalance.maxiter','size',[1],'>=',1)
 		md = checkfield(md,'fieldname','stressbalance.referential','size',[md.mesh.numberofvertices,6])
Index: /issm/trunk-jpl/src/py3/classes/taoinversion.py
===================================================================
--- /issm/trunk-jpl/src/py3/classes/taoinversion.py	(revision 19897)
+++ /issm/trunk-jpl/src/py3/classes/taoinversion.py	(revision 19898)
@@ -156,10 +156,10 @@
 
 		if solution==BalancethicknessSolutionEnum():
-			md = checkfield(md,'fieldname','inversion.thickness_obs','size',[md.mesh.numberofvertices, 1],'NaN',1)
+			md = checkfield(md,'fieldname','inversion.thickness_obs','size',[md.mesh.numberofvertices, 1],'NaN',1,'Inf',1)
 		elif solution==BalancethicknessSoftSolutionEnum():
-			md = checkfield(md,'fieldname','inversion.thickness_obs','size',[md.mesh.numberofvertices, 1],'NaN',1)
+			md = checkfield(md,'fieldname','inversion.thickness_obs','size',[md.mesh.numberofvertices, 1],'NaN',1,'Inf',1)
 		else:
-			md = checkfield(md,'fieldname','inversion.vx_obs','size',[md.mesh.numberofvertices, 1],'NaN',1)
-			md = checkfield(md,'fieldname','inversion.vy_obs','size',[md.mesh.numberofvertices, 1],'NaN',1)
+			md = checkfield(md,'fieldname','inversion.vx_obs','size',[md.mesh.numberofvertices, 1],'NaN',1,'Inf',1)
+			md = checkfield(md,'fieldname','inversion.vy_obs','size',[md.mesh.numberofvertices, 1],'NaN',1,'Inf',1)
 
 		def marshall(self, md, fid):
Index: /issm/trunk-jpl/src/py3/classes/timestepping.py
===================================================================
--- /issm/trunk-jpl/src/py3/classes/timestepping.py	(revision 19897)
+++ /issm/trunk-jpl/src/py3/classes/timestepping.py	(revision 19898)
@@ -53,7 +53,7 @@
 	def checkconsistency(self,md,solution,analyses):    # {{{
 
-		md = checkfield(md,'fieldname','timestepping.start_time','numel',[1],'NaN',1)
-		md = checkfield(md,'fieldname','timestepping.final_time','numel',[1],'NaN',1)
-		md = checkfield(md,'fieldname','timestepping.time_step','numel',[1],'>=',0,'NaN',1)
+		md = checkfield(md,'fieldname','timestepping.start_time','numel',[1],'NaN',1,'Inf',1)
+		md = checkfield(md,'fieldname','timestepping.final_time','numel',[1],'NaN',1,'Inf',1)
+		md = checkfield(md,'fieldname','timestepping.time_step','numel',[1],'>=',0,'NaN',1,'Inf',1)
 		md = checkfield(md,'fieldname','timestepping.time_adapt','numel',[1],'values',[0,1])
 		md = checkfield(md,'fieldname','timestepping.cfl_coefficient','numel',[1],'>',0,'<=',1)
