--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/+sbp/D4CompatibleVariable.m	Wed Sep 07 13:40:41 2016 +0200
@@ -0,0 +1,63 @@
+classdef D4CompatibleVariable < sbp.OpSet
+    properties
+        norms % Struct containing norm matrices such as H,Q, M
+        boundary  % Struct contanging vectors for boundry point approximations
+        derivatives % Struct containging differentiation operators
+        borrowing % Struct with borrowing limits for different norm matrices
+        m % Number of grid points.
+        h % Step size
+    end
+
+
+
+    methods
+        function obj = D4CompatibleVariable(m,h,order)
+
+            if order == 2
+                [H, HI, D1, D2, D3, D4, e_1, e_m, M4, Q, S2_1, S2_m, S3_1, S3_m, S_1, S_m] = sbp.higher2_compatible_halfvariable(m,h);
+                obj.borrowing.N.S2 = 1.2500;
+                obj.borrowing.N.S3 = 0.4000;
+            elseif order == 4
+                [H, HI, D2, D4, e_1, e_m, M4, S2_1, S2_m, S3_1, S3_m, S_1, S_m] = sbp.higher4_compatible_halfvariable(m,h);
+                obj.borrowing.N.S2 = 0.5055;
+                obj.borrowing.N.S3 = 0.9290;
+            elseif order == 6
+                [H, HI, D2, D4, e_1, e_m, M4, S2_1, S2_m, S3_1, S3_m, S_1, S_m] = sbp.higher6_compatible_halfvariable(m,h);
+                obj.borrowing.N.S2 = 0.3259;
+                obj.borrowing.N.S3 = 0.1580;
+            else
+                error('Invalid operator order.');
+            end
+
+            obj.h = h;
+            obj.m = m;
+
+            obj.norms.H = H;
+            obj.norms.HI = HI;
+            obj.norms.N = M4;
+
+            obj.boundary.e_1 = e_1;
+            obj.boundary.S_1 = S_1;
+            obj.boundary.S2_1 = S2_1;
+            obj.boundary.S3_1 = S3_1;
+
+            obj.boundary.e_m = e_m;
+            obj.boundary.S_m = S_m;
+            obj.boundary.S2_m = S2_m;
+            obj.boundary.S3_m = S3_m;
+
+            obj.derivatives.D2 = D2;
+            obj.derivatives.D4 = D4;
+
+        end
+    end
+
+    methods (Static)
+        function lambda = smallestGrid(obj)
+            error('Not implmented')
+        end
+    end
+
+
+
+end
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