--- a/+multiblock/DiffOp.m	Mon Dec 03 14:53:52 2018 -0800
+++ b/+multiblock/DiffOp.m	Mon Dec 03 15:01:24 2018 -0800
@@ -10,7 +10,7 @@
     end
 
     methods
-        function obj = DiffOp(doHand, grid, order, doParam, intfOpts)
+        function obj = DiffOp(doHand, grid, order, doParam, intfTypes)
             %  doHand -- may either be a function handle or a cell array of
             %            function handles for each grid. The function handle(s)
             %            should be on the form do = doHand(grid, order, ...)
@@ -25,10 +25,10 @@
             %            doHand(..., doParam{i}{:}) Otherwise doParam is sent as
             %            extra parameters to all doHand: doHand(..., doParam{:})
             %
-            % intfOpts (optional) -- nBlocks x nBlocks cell array of options for
+            % intfTypes (optional) -- nBlocks x nBlocks cell array of types for
             %                                 every interface.
             default_arg('doParam', [])
-            default_arg('intfOpts', cell(grid.nBlocks(), grid.nBlocks()) );
+            default_arg('intfTypes', cell(grid.nBlocks(), grid.nBlocks()) );
 
             [getHand, getParam] = parseInput(doHand, grid, doParam);
 
@@ -69,11 +69,11 @@
                         continue
                     end
 
-                    [ii, ij] = obj.diffOps{i}.interface(intf{1}, obj.diffOps{j}, intf{2}, intfOpts{i,j});
+                    [ii, ij] = obj.diffOps{i}.interface(intf{1}, obj.diffOps{j}, intf{2}, intfTypes{i,j});
                     D{i,i} = D{i,i} + ii;
                     D{i,j} = D{i,j} + ij;
 
-                    [jj, ji] = obj.diffOps{j}.interface(intf{2}, obj.diffOps{i}, intf{1}, intfOpts{i,j});
+                    [jj, ji] = obj.diffOps{j}.interface(intf{2}, obj.diffOps{i}, intf{1}, intfTypes{i,j});
                     D{j,j} = D{j,j} + jj;
                     D{j,i} = D{j,i} + ji;
                 end