--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/+sbp/InterpOpsOP.m	Mon Dec 03 14:53:52 2018 -0800
@@ -0,0 +1,61 @@
+classdef InterpOpsOP < sbp.InterpOps
+    properties
+
+        % Structs of interpolation operators, fields .good and .bad
+        Iu2v
+        Iv2u
+    end
+
+    methods
+        % x_u, x_v         --   vectors of the coordinate that varies along the boundary
+        % order_u, order_v --   order of accuracy in the different blocks
+        function obj = InterpOpsOP(x_u, x_v, order_u, order_v)
+
+            assert(order_u == order_v,...
+                    'InterpOpsOP: Different orders of accuracy not available');
+
+            switch order_u
+            case 2
+                intOpSet = @sbp.implementations.intOpOP_orders_2to2_ratio2to1;
+            case 4
+                intOpSet = @sbp.implementations.intOpOP_orders_4to4_ratio2to1;
+            case 6
+                intOpSet = @sbp.implementations.intOpOP_orders_6to6_ratio2to1;
+            case 8
+                intOpSet = @sbp.implementations.intOpOP_orders_8to8_ratio2to1;
+            otherwise
+                error('InterpOpsOP: Order of accuracy %d not available.', order_u);
+            end
+
+            m_u = length(x_u) - 1;
+            m_v = length(x_v) - 1;
+
+            Iu2v = struct;
+            Iv2u = struct;
+
+            if m_u/m_v == 2
+                % Block u is fine, v is coarse
+                m_C = m_v;
+                [Iv2u.good, Iu2v.bad] = intOpSet(m_C+1, 1, 'C2F');
+                [Iv2u.bad, Iu2v.good] = intOpSet(m_C+1, 1, 'F2C');
+
+            elseif m_v/m_u == 2
+                % Block v is fine, u is coarse
+                m_C = m_u;
+                [Iu2v.good, Iv2u.bad] = intOpSet(m_C+1, 1, 'C2F');
+                [Iu2v.bad, Iv2u.good] = intOpSet(m_C+1, 1, 'F2C');
+            else
+                error('InterpOpsOP: Interpolation operators for grid ratio %f have not yet been constructed', m_u/m_v);
+            end
+
+            obj.Iu2v = Iu2v;
+            obj.Iv2u = Iv2u;
+
+        end
+
+        function str = string(obj)
+            str = [class(obj)];
+        end
+
+    end
+end