--- a/+sbp/+implementations/d4_variable_6_2.m	Fri Sep 23 22:58:45 2016 +0200
+++ b/+sbp/+implementations/d4_variable_6_2.m	Fri Sep 23 23:10:44 2016 +0200
@@ -42,12 +42,17 @@
     S_m = zeros(1,m);
     S_m(m-5:m) = fliplr(-S_U);
 
-
+    S2_U = [0.15e2/0.4e1 -0.77e2/0.6e1 0.107e3/0.6e1 -13 0.61e2/0.12e2 -0.5e1/0.6e1;]/h^2;
+    S2_1 = zeros(1,m);
+    S2_1(1:6) = S2_U;
+    S2_m = zeros(1,m);
+    S2_m(m-5:m) = fliplr(S2_U);
 
-    %DS = zeros(m,m);
-    %DS(1,1:5) = -[-25/12, 4, -3, 4/3, -1/4];
-    %DS(m,m-4:m) = fliplr(-[-25/12, 4, -3, 4/3, -1/4]);
-    %DS = diag(c)*DS/h;
+    S3_U = [-0.17e2/0.4e1 0.71e2/0.4e1 -0.59e2/0.2e1 0.49e2/0.2e1 -0.41e2/0.4e1 0.7e1/0.4e1;]/h^3;
+    S3_1 = zeros(1,m);
+    S3_1(1:6) = S3_U;
+    S3_m = zeros(1,m);
+    S3_m(m-5:m) = fliplr(-S3_U);
 
 
     H = h*H;
@@ -92,15 +97,6 @@
     %
     % D2=HI*(-M-diag(c)*e_1*S_1+diag(c)*e_m*S_m);
 
-    S2_U = [0.15e2/0.4e1 -0.77e2/0.6e1 0.107e3/0.6e1 -13 0.61e2/0.12e2 -0.5e1/0.6e1;]/h^2;
-    S2_1 = zeros(1,m);
-    S2_1(1:6) = S2_U;
-    S2_m = zeros(1,m);
-    S2_m(m-5:m) = fliplr(S2_U);
-
-
-
-
 
     % Fourth derivative, 1th order accurate at first 8 boundary points (still
     % yield 5th order convergence if stable: for example u_tt = -u_xxxx
@@ -129,13 +125,5 @@
     M4(m-5:m,m-5:m) = flipud( fliplr( M4_U ) );
     M4 = M4/h^3;
 
-    S3_U = [-0.17e2/0.4e1 0.71e2/0.4e1 -0.59e2/0.2e1 0.49e2/0.2e1 -0.41e2/0.4e1 0.7e1/0.4e1;]/h^3;
-    S3_1 = zeros(1,m);
-    S3_1(1:6) = S3_U;
-    S3_m = zeros(1,m);
-    S3_m(m-5:m) = fliplr(-S3_U);
-
     D4 = HI*(M4-e_1*S3_1+e_m*S3_m  + S_1'*S2_1-S_m'*S2_m);
-
-
 end