Index: /issm/trunk-jpl/src/m/classes/sampling.m
===================================================================
--- /issm/trunk-jpl/src/m/classes/sampling.m	(revision 26022)
+++ /issm/trunk-jpl/src/m/classes/sampling.m	(revision 26023)
@@ -66,8 +66,10 @@
             md = checkfield(md,'fieldname','sampling.kappa','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices 1],'>',0);
             md = checkfield(md,'fieldname','sampling.tau','NaN',1,'Inf',1,'numel',1,'>',0);
-            md = checkfield(md,'fieldname','sampling.beta','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices 1],'>',0);
+            md = checkfield(md,'fieldname','sampling.robin','numel',1,'values',[0 1]);
+            if(md.sampling.robin)
+                md = checkfield(md,'fieldname','sampling.beta','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices 1],'>',0);
+            end    
             md = checkfield(md,'fieldname','sampling.phi','NaN',1,'Inf',1,'numel',1,'>=',0);
             md = checkfield(md,'fieldname','sampling.alpha','NaN',1,'Inf',1,'numel',1,'>',0);
-            md = checkfield(md,'fieldname','sampling.robin','numel',1,'values',[0 1]);
             md = checkfield(md,'fieldname','sampling.seed','NaN',1,'Inf',1,'numel',1);
             md = checkfield(md,'fieldname','sampling.requested_outputs','stringrow',1);
Index: /issm/trunk-jpl/src/m/classes/sampling.py
===================================================================
--- /issm/trunk-jpl/src/m/classes/sampling.py	(revision 26022)
+++ /issm/trunk-jpl/src/m/classes/sampling.py	(revision 26023)
@@ -70,8 +70,9 @@
         md = checkfield(md,'fieldname','sampling.kappa','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices],'>',0)
         md = checkfield(md,'fieldname','sampling.tau','NaN',1,'Inf',1,'numel',1,'>',0)
-        md = checkfield(md,'fieldname','sampling.beta','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices],'>',0)
+        md = checkfield(md,'fieldname','sampling.robin','numel',1,'values',[0, 1])
+        if md.sampling.robin:
+            md = checkfield(md,'fieldname','sampling.beta','NaN',1,'Inf',1,'size',[md.mesh.numberofvertices],'>',0)
         md = checkfield(md,'fieldname','sampling.phi','NaN',1,'Inf',1,'numel',1,'>=',0)
         md = checkfield(md,'fieldname','sampling.alpha','NaN',1,'Inf',1,'numel',1,'>',0)
-        md = checkfield(md,'fieldname','sampling.robin','numel',1,'values',[0, 1])
         md = checkfield(md,'fieldname','sampling.seed','NaN',1,'Inf',1,'numel',1)
         md = checkfield(md,'fieldname','sampling.requested_outputs','stringrow',1)