Index: /issm/trunk-jpl/src/m/classes/inversion.m
===================================================================
--- /issm/trunk-jpl/src/m/classes/inversion.m	(revision 13147)
+++ /issm/trunk-jpl/src/m/classes/inversion.m	(revision 13148)
@@ -83,17 +83,17 @@
 			num_costfunc=size(md.inversion.cost_functions,2);
 
-			checkfield(md,'inversion.iscontrol','values',[0 1]);
-			checkfield(md,'inversion.tao','values',[0 1]);
-			checkfield(md,'inversion.incomplete_adjoint','values',[0 1]);
-			checkfield(md,'inversion.control_parameters','cell',1,'values',{'BalancethicknessThickeningRate' 'FrictionCoefficient' 'MaterialsRheologyBbar' 'MaterialsRheologyZbar' 'Vx' 'Vy'});
-			checkfield(md,'inversion.nsteps','numel',1,'>=',1);
-			checkfield(md,'inversion.maxiter_per_step','size',[md.inversion.nsteps 1],'>=',0);
-			checkfield(md,'inversion.step_threshold','size',[md.inversion.nsteps 1]);
-			checkfield(md,'inversion.cost_functions','size',[md.inversion.nsteps num_costfunc],'values',[101:105 201 501:503]);
-			checkfield(md,'inversion.cost_functions_coefficients','size',[md.mesh.numberofvertices num_costfunc],'>=',0);
-			checkfield(md,'inversion.gradient_only','values',[0 1]);
-			checkfield(md,'inversion.gradient_scaling','size',[md.inversion.nsteps num_controls]);
-			checkfield(md,'inversion.min_parameters','size',[md.mesh.numberofvertices num_controls]);
-			checkfield(md,'inversion.max_parameters','size',[md.mesh.numberofvertices num_controls]);
+			md = checkfield(md,'inversion.iscontrol','values',[0 1]);
+			md = checkfield(md,'inversion.tao','values',[0 1]);
+			md = checkfield(md,'inversion.incomplete_adjoint','values',[0 1]);
+			md = checkfield(md,'inversion.control_parameters','cell',1,'values',{'BalancethicknessThickeningRate' 'FrictionCoefficient' 'MaterialsRheologyBbar' 'MaterialsRheologyZbar' 'Vx' 'Vy'});
+			md = checkfield(md,'inversion.nsteps','numel',1,'>=',1);
+			md = checkfield(md,'inversion.maxiter_per_step','size',[md.inversion.nsteps 1],'>=',0);
+			md = checkfield(md,'inversion.step_threshold','size',[md.inversion.nsteps 1]);
+			md = checkfield(md,'inversion.cost_functions','size',[md.inversion.nsteps num_costfunc],'values',[101:105 201 501:505]);
+			md = checkfield(md,'inversion.cost_functions_coefficients','size',[md.mesh.numberofvertices num_costfunc],'>=',0);
+			md = checkfield(md,'inversion.gradient_only','values',[0 1]);
+			md = checkfield(md,'inversion.gradient_scaling','size',[md.inversion.nsteps num_controls]);
+			md = checkfield(md,'inversion.min_parameters','size',[md.mesh.numberofvertices num_controls]);
+			md = checkfield(md,'inversion.max_parameters','size',[md.mesh.numberofvertices num_controls]);
 
 			if solution==BalancethicknessSolutionEnum()