Mercurial > repos > public > sbplib

changeset 266:bfa130b7abf6 operator_remake

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Added error message for too few grid points to all implementation files.
author Martin Almquist <martin.almquist@it.uu.se>
date Fri, 09 Sep 2016 11:03:13 +0200
parents 3e0432b3cb68
children f7ac3cd6eeaa
files +sbp/+implementations/d1_noneq_10.m +sbp/+implementations/d1_noneq_12.m +sbp/+implementations/d1_noneq_4.m +sbp/+implementations/d1_noneq_6.m +sbp/+implementations/d1_noneq_8.m +sbp/+implementations/d1_noneq_minimal_10.m +sbp/+implementations/d1_noneq_minimal_12.m +sbp/+implementations/d1_noneq_minimal_4.m +sbp/+implementations/d1_noneq_minimal_6.m +sbp/+implementations/d1_noneq_minimal_8.m +sbp/+implementations/d1_upwind_2.m +sbp/+implementations/d1_upwind_3.m +sbp/+implementations/d1_upwind_4.m +sbp/+implementations/d1_upwind_5.m +sbp/+implementations/d1_upwind_6.m +sbp/+implementations/d1_upwind_7.m +sbp/+implementations/d1_upwind_8.m +sbp/+implementations/d1_upwind_9.m +sbp/+implementations/d2_10.m +sbp/+implementations/d2_12.m +sbp/+implementations/d2_2.m +sbp/+implementations/d2_4.m +sbp/+implementations/d2_6.m +sbp/+implementations/d2_8.m +sbp/+implementations/d2_blocknorm_10.m +sbp/+implementations/d2_blocknorm_4.m +sbp/+implementations/d2_blocknorm_6.m +sbp/+implementations/d2_blocknorm_8.m +sbp/+implementations/d2_variable_4.m +sbp/+implementations/d4_4.m +sbp/+implementations/d4_6.m +sbp/+implementations/d4_compatible_2.m +sbp/+implementations/d4_compatible_4.m +sbp/+implementations/d4_compatible_6.m +sbp/+implementations/d4_compatible_halfvariable_2.m +sbp/+implementations/d4_compatible_halfvariable_4.m +sbp/+implementations/d4_compatible_halfvariable_6.m
diffstat 37 files changed, 185 insertions(+), 0 deletions(-) [+]
line wrap: on
line diff
--- a/+sbp/+implementations/d1_noneq_10.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d1_noneq_10.m	Fri Sep 09 11:03:13 2016 +0200
@@ -6,6 +6,10 @@
     L = 1;
 end
 
+if(N<20)
+    error('Operator requires at least 20 grid points');
+end
+
 % BP: Number of boundary points
 % m:  Number of nonequidistant spacings
 % order: Accuracy of interior stencil
--- a/+sbp/+implementations/d1_noneq_12.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d1_noneq_12.m	Fri Sep 09 11:03:13 2016 +0200
@@ -6,6 +6,10 @@
     L = 1;
 end
 
+if(N<24)
+    error('Operator requires at least 24 grid points');
+end
+
 % BP: Number of boundary points
 % m:  Number of nonequidistant spacings
 % order: Accuracy of interior stencil
--- a/+sbp/+implementations/d1_noneq_4.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d1_noneq_4.m	Fri Sep 09 11:03:13 2016 +0200
@@ -6,6 +6,10 @@
     L = 1;
 end
 
+if(N<8)
+    error('Operator requires at least 8 grid points');
+end
+
 % BP: Number of boundary points
 % m:  Number of nonequidistant spacings
 % order: Accuracy of interior stencil
--- a/+sbp/+implementations/d1_noneq_6.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d1_noneq_6.m	Fri Sep 09 11:03:13 2016 +0200
@@ -6,6 +6,10 @@
     L = 1;
 end
 
+if(N<12)
+    error('Operator requires at least 12 grid points');
+end
+
 % BP: Number of boundary points
 % m:  Number of nonequidistant spacings
 % order: Accuracy of interior stencil
--- a/+sbp/+implementations/d1_noneq_8.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d1_noneq_8.m	Fri Sep 09 11:03:13 2016 +0200
@@ -6,6 +6,10 @@
     L = 1;
 end
 
+if(N<16)
+    error('Operator requires at least 16 grid points');
+end
+
 % BP: Number of boundary points
 % m:  Number of nonequidistant spacings
 % order: Accuracy of interior stencil
--- a/+sbp/+implementations/d1_noneq_minimal_10.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d1_noneq_minimal_10.m	Fri Sep 09 11:03:13 2016 +0200
@@ -6,6 +6,10 @@
     L = 1;
 end
 
+if(N<16)
+    error('Operator requires at least 16 grid points');
+end
+
 % BP: Number of boundary points
 % m:  Number of nonequidistant spacings
 % order: Accuracy of interior stencil
--- a/+sbp/+implementations/d1_noneq_minimal_12.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d1_noneq_minimal_12.m	Fri Sep 09 11:03:13 2016 +0200
@@ -6,6 +6,10 @@
     L = 1;
 end
 
+if(N<20)
+    error('Operator requires at least 20 grid points');
+end
+
 % BP: Number of boundary points
 % m:  Number of nonequidistant spacings
 % order: Accuracy of interior stencil
--- a/+sbp/+implementations/d1_noneq_minimal_4.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d1_noneq_minimal_4.m	Fri Sep 09 11:03:13 2016 +0200
@@ -6,6 +6,10 @@
     L = 1;
 end
 
+if(N<6)
+    error('Operator requires at least 6 grid points');
+end
+
 % BP: Number of boundary points
 % m:  Number of nonequidistant spacings
 % order: Accuracy of interior stencil
--- a/+sbp/+implementations/d1_noneq_minimal_6.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d1_noneq_minimal_6.m	Fri Sep 09 11:03:13 2016 +0200
@@ -6,6 +6,10 @@
     L = 1;
 end
 
+if(N<10)
+    error('Operator requires at least 10 grid points');
+end
+
 % BP: Number of boundary points
 % m:  Number of nonequidistant spacings
 % order: Accuracy of interior stencil
--- a/+sbp/+implementations/d1_noneq_minimal_8.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d1_noneq_minimal_8.m	Fri Sep 09 11:03:13 2016 +0200
@@ -6,6 +6,10 @@
     L = 1;
 end
 
+if(N<12)
+    error('Operator requires at least 12 grid points');
+end
+
 % BP: Number of boundary points
 % m:  Number of nonequidistant spacings
 % order: Accuracy of interior stencil
--- a/+sbp/+implementations/d1_upwind_2.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d1_upwind_2.m	Fri Sep 09 11:03:13 2016 +0200
@@ -1,4 +1,9 @@
 function [H, HI, Dp, Dm, e_1, e_m] = d1_upwind_2(m,h)
+    
+    if(m<4)
+        error('Operator requires at least 4 grid points');
+    end
+
     Hv=ones(m,1);
     Hv(1:2)=[0.1e1/0.4e1; 0.5e1/0.4e1;];
     Hv(m-1:m)=rot90(Hv(1:2),2);
--- a/+sbp/+implementations/d1_upwind_3.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d1_upwind_3.m	Fri Sep 09 11:03:13 2016 +0200
@@ -1,4 +1,9 @@
 function [H, HI, Dp, Dm, e_1, e_m] = d1_upwind_3(m,h)
+    
+    if(m<6)
+        error('Operator requires at least 6 grid points');
+    end
+
     Hv = ones(m,1);
     Hv(1:3) = [3/8; 7/6; 23/24];
     Hv(m-2:m) = rot90(Hv(1:3),2);
--- a/+sbp/+implementations/d1_upwind_4.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d1_upwind_4.m	Fri Sep 09 11:03:13 2016 +0200
@@ -1,5 +1,9 @@
 function [H, HI, Dp, Dm, e_1, e_m] = d1_upwind_4(m,h)
 
+    if(m<8)
+        error('Operator requires at least 8 grid points');
+    end
+
     Hv=ones(m,1);
     Hv(1:4)=[49/144 61/48 41/48 149/144];
     Hv(m-3:m)=rot90(Hv(1:4),2);
--- a/+sbp/+implementations/d1_upwind_5.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d1_upwind_5.m	Fri Sep 09 11:03:13 2016 +0200
@@ -1,4 +1,9 @@
 function [H, HI, Dp, Dm, e_1, e_m] = d1_upwind_5(m,h)
+    
+    if(m<8)
+        error('Operator requires at least 8 grid points');
+    end
+
     Hv=ones(m,1);
     Hv(1:4)=[0.251e3/0.720e3; 0.299e3/0.240e3; 0.211e3/0.240e3; 0.739e3/0.720e3;];
     Hv(m-3:m)=rot90(Hv(1:4),2);
--- a/+sbp/+implementations/d1_upwind_6.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d1_upwind_6.m	Fri Sep 09 11:03:13 2016 +0200
@@ -1,4 +1,9 @@
 function [H, HI, Dp, Dm, e_1, e_m] = d1_upwind_6(m,h)
+    
+    if(m<12)
+        error('Operator requires at least 12 grid points');
+    end
+
     Hv = ones(m,1);
     Hv(1:6)=[0.13613e5/0.43200e5; 0.12049e5/0.8640e4 ; 0.535e3/0.864e3 ; 0.1079e4/0.864e3 ;  0.7841e4/0.8640e4 ; 0.43837e5/0.43200e5];
     Hv(m-5:m)=rot90(Hv(1:6),2);
--- a/+sbp/+implementations/d1_upwind_7.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d1_upwind_7.m	Fri Sep 09 11:03:13 2016 +0200
@@ -1,5 +1,10 @@
 function [H, HI, Dp, Dm, e_1, e_m] = d1_upwind_7(m,h)
 
+    BP = 6;
+    if(m<2*BP)
+        error(['Operator requires at least ' num2str(2*BP) ' grid points']);
+    end
+
     Hv=ones(m,1);
     Hv(1:6) = [0.19087e5/0.60480e5; 0.84199e5/0.60480e5; 0.18869e5/0.30240e5; 0.37621e5/0.30240e5; 0.55031e5/0.60480e5; 0.61343e5/0.60480e5; ];
     Hv(m-5:m)=rot90(Hv(1:6),2);
--- a/+sbp/+implementations/d1_upwind_8.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d1_upwind_8.m	Fri Sep 09 11:03:13 2016 +0200
@@ -1,4 +1,10 @@
 function [H, HI, Dp, Dm, e_1, e_m] = d1_upwind_8(m,h)
+    
+    BP = 8;
+    if(m<2*BP)
+        error(['Operator requires at least ' num2str(2*BP) ' grid points']);
+    end
+
     Hv=ones(m,1);
     Hv(1:8) = [0.7489399e7/0.25401600e8; 0.5537831e7/0.3628800e7; 0.103373e6/0.403200e6; 0.261259e6/0.145152e6; 0.298231e6/0.725760e6; 0.515917e6/0.403200e6; 0.3349159e7/0.3628800e7; 0.25639991e8/0.25401600e8];
     Hv(m-7:m)=rot90(Hv(1:8),2);
--- a/+sbp/+implementations/d1_upwind_9.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d1_upwind_9.m	Fri Sep 09 11:03:13 2016 +0200
@@ -1,5 +1,10 @@
 function [H, HI, Dp, Dm, e_1, e_m] = d1_upwind_9(m,h)
 
+    BP = 8;
+    if(m<2*BP)
+        error(['Operator requires at least ' num2str(2*BP) ' grid points']);
+    end
+
     Hv=ones(m,1);
     Hv(1:8) = [0.1070017e7/0.3628800e7; 0.5537111e7/0.3628800e7; 0.103613e6/0.403200e6; 0.261115e6/0.145152e6; 0.298951e6/0.725760e6; 0.515677e6/0.403200e6; 0.3349879e7/0.3628800e7; 0.3662753e7/0.3628800e7;];
     Hv(m-7:m)=rot90(Hv(1:8),2);
--- a/+sbp/+implementations/d2_10.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d2_10.m	Fri Sep 09 11:03:13 2016 +0200
@@ -1,5 +1,10 @@
 function [H, HI, D1, D2, e_1, e_m, M, Q, S_1, S_m] = d2_10(m,h)
 
+    BP = 11;
+    if(m<2*BP)
+        error(['Operator requires at least ' num2str(2*BP) ' grid points']);
+    end
+
     H_U = [0.5261271563e10 / 0.18289152000e11 0 0 0 0 0 0 0 0 0 0; 0 0.2881040311e10 / 0.1828915200e10 0 0 0 0 0 0 0 0 0; 0 0 0.52175551e8 / 0.406425600e9 0 0 0 0 0 0 0 0; 0 0 0 0.11662993e8 / 0.6096384e7 0 0 0 0 0 0 0; 0 0 0 0 0.50124587e8 / 0.87091200e8 0 0 0 0 0 0; 0 0 0 0 0 0.50124587e8 / 0.72576000e8 0 0 0 0 0; 0 0 0 0 0 0 0.148333439e9 / 0.87091200e8 0 0 0 0; 0 0 0 0 0 0 0 0.63867949e8 / 0.152409600e9 0 0 0; 0 0 0 0 0 0 0 0 0.20608675e8 / 0.16257024e8 0 0; 0 0 0 0 0 0 0 0 0 0.1704508063e10 / 0.1828915200e10 0; 0 0 0 0 0 0 0 0 0 0 0.18425967263e11 / 0.18289152000e11;];
 
     H=eye(m);
--- a/+sbp/+implementations/d2_12.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d2_12.m	Fri Sep 09 11:03:13 2016 +0200
@@ -2,6 +2,11 @@
 
 % D2 = D1*D1, wide!
 
+BP = 15;
+if(m<2*BP)
+    error(['Operator requires at least ' num2str(2*BP) ' grid points']);
+end
+
 H=diag(ones(m,1),0);
 H(1:15,1:15)=diag([2.880607858916397e-01,...
     1.560376162339675e+00,...
--- a/+sbp/+implementations/d2_2.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d2_2.m	Fri Sep 09 11:03:13 2016 +0200
@@ -1,4 +1,10 @@
 function [H, HI, D1, D2, e_1, e_m, M, Q, S_1, S_m] = d2_2(m,h)
+    
+    BP = 1;
+    if(m<2*BP)
+        error(['Operator requires at least ' num2str(2*BP) ' grid points']);
+    end
+
     e_1=zeros(m,1);e_1(1)=1;
     e_m=zeros(m,1);e_m(m)=1;
 
--- a/+sbp/+implementations/d2_4.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d2_4.m	Fri Sep 09 11:03:13 2016 +0200
@@ -1,4 +1,10 @@
 function [H, HI, D1, D2, e_1, e_m, M, Q, S_1, S_m] = d2_4(m,h)
+    
+    BP = 4;
+    if(m<2*BP)
+        error(['Operator requires at least ' num2str(2*BP) ' grid points']);
+    end
+
     e_1=zeros(m,1);e_1(1)=1;
     e_m=zeros(m,1);e_m(m)=1;
 
--- a/+sbp/+implementations/d2_6.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d2_6.m	Fri Sep 09 11:03:13 2016 +0200
@@ -1,4 +1,10 @@
 function [H, HI, D1, D2, e_1, e_m, M, Q, S_1, S_m] = d2_6(m,h)
+    
+    BP = 6;
+    if(m<2*BP)
+        error(['Operator requires at least ' num2str(2*BP) ' grid points']);
+    end
+
     e_1=zeros(m,1);e_1(1)=1;
     e_m=zeros(m,1);e_m(m)=1;
 
--- a/+sbp/+implementations/d2_8.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d2_8.m	Fri Sep 09 11:03:13 2016 +0200
@@ -1,4 +1,11 @@
 function [H, HI, D1, D2, e_1, e_m, M, Q, S_1, S_m] = d2_8(m,h)
+    
+
+    BP = 8;
+    if(m<2*BP)
+        error(['Operator requires at least ' num2str(2*BP) ' grid points']);
+    end
+
     H=diag(ones(m,1),0);
     H(1:8,1:8)=diag([1498139/5080320, 1107307/725760, 20761/80640, 1304999/725760, 299527/725760, 103097/80640, 670091/725760, 5127739/5080320]);
     H(m-7:m,m-7:m)=fliplr(flipud(diag([1498139/5080320, 1107307/725760, 20761/80640, 1304999/725760, 299527/725760, 103097/80640, 670091/725760, 5127739/5080320])));
--- a/+sbp/+implementations/d2_blocknorm_10.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d2_blocknorm_10.m	Fri Sep 09 11:03:13 2016 +0200
@@ -1,4 +1,10 @@
 function [H, HI, D1, D2, e_1, e_m, M, Q, S_1, S_m] = d2_blocknorm_10(m,h)
+
+    BP = 9;
+    if(m<2*BP)
+        error(['Operator requires at least ' num2str(2*BP) ' grid points']);
+    end
+
     H_U=[0.428081020217e12 / 0.2633637888000e13 0.779032713983e12 / 0.2633637888000e13 -0.1187642619571e13 / 0.2633637888000e13 0.1642279196603e13 / 0.2633637888000e13 -0.339289243121e12 / 0.526727577600e12 0.1261055176253e13 / 0.2633637888000e13 -0.658216413073e12 / 0.2633637888000e13 0.33968779823e11 / 0.376233984000e12 -0.764998e6 / 0.40186125e8; 0.779032713983e12 / 0.2633637888000e13 0.317907052061e12 / 0.164602368000e12 -0.1082918052397e13 / 0.658409472000e12 0.176473501369e12 / 0.82301184000e11 -0.521625191587e12 / 0.263363788800e12 0.200523313337e12 / 0.164602368000e12 -0.279496000009e12 / 0.658409472000e12 -0.832e3 / 0.40186125e8 0.129794760887e12 / 0.2633637888000e13; -0.1187642619571e13 / 0.2633637888000e13 -0.1082918052397e13 / 0.658409472000e12 0.1304108863849e13 / 0.329204736000e12 -0.533093695961e12 / 0.131681894400e12 0.213949854133e12 / 0.52672757760e11 -0.1883976009151e13 / 0.658409472000e12 0.51084128e8 / 0.40186125e8 -0.92763684343e11 / 0.658409472000e12 -0.59058717923e11 / 0.526727577600e12; 0.1642279196603e13 / 0.2633637888000e13 0.176473501369e12 / 0.82301184000e11 -0.533093695961e12 / 0.131681894400e12 0.217677310051e12 / 0.32920473600e11 -0.1509120465127e13 / 0.263363788800e12 0.170839232e9 / 0.40186125e8 -0.1404096707137e13 / 0.658409472000e12 0.11789520859e11 / 0.32920473600e11 0.85652315431e11 / 0.526727577600e12; -0.339289243121e12 / 0.526727577600e12 -0.521625191587e12 / 0.263363788800e12 0.213949854133e12 / 0.52672757760e11 -0.1509120465127e13 / 0.263363788800e12 0.21849109e8 / 0.3214890e7 -0.1134422468377e13 / 0.263363788800e12 0.602448430967e12 / 0.263363788800e12 -0.4910542309e10 / 0.10534551552e11 -0.83039945231e11 / 0.526727577600e12; 0.1261055176253e13 / 0.2633637888000e13 0.200523313337e12 / 0.164602368000e12 -0.1883976009151e13 / 0.658409472000e12 0.170839232e9 / 0.40186125e8 -0.1134422468377e13 / 0.263363788800e12 0.681437038097e12 / 0.164602368000e12 -0.1108257453763e13 / 0.658409472000e12 0.31631872327e11 / 0.82301184000e11 0.37820115539e11 / 0.376233984000e12; -0.658216413073e12 / 0.2633637888000e13 -0.279496000009e12 / 0.658409472000e12 0.51084128e8 / 0.40186125e8 -0.1404096707137e13 / 0.658409472000e12 0.602448430967e12 / 0.263363788800e12 -0.1108257453763e13 / 0.658409472000e12 0.623491124887e12 / 0.329204736000e12 -0.146643738067e12 / 0.658409472000e12 -0.98874149197e11 / 0.2633637888000e13; 0.33968779823e11 / 0.376233984000e12 -0.832e3 / 0.40186125e8 -0.92763684343e11 / 0.658409472000e12 0.11789520859e11 / 0.32920473600e11 -0.4910542309e10 / 0.10534551552e11 0.31631872327e11 / 0.82301184000e11 -0.146643738067e12 / 0.658409472000e12 0.174599973347e12 / 0.164602368000e12 0.4625165773e10 / 0.526727577600e12; -0.764998e6 / 0.40186125e8 0.129794760887e12 / 0.2633637888000e13 -0.59058717923e11 / 0.526727577600e12 0.85652315431e11 / 0.526727577600e12 -0.83039945231e11 / 0.526727577600e12 0.37820115539e11 / 0.376233984000e12 -0.98874149197e11 / 0.2633637888000e13 0.4625165773e10 / 0.526727577600e12 0.525286231387e12 / 0.526727577600e12;];
 
 
--- a/+sbp/+implementations/d2_blocknorm_4.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d2_blocknorm_4.m	Fri Sep 09 11:03:13 2016 +0200
@@ -1,4 +1,10 @@
 function [H, HI, D1, D2, e_1, e_m, M, Q, S_1, S_m] = d2_blocknorm_4(m,h)
+    
+    BP = 4;
+    if(m<2*BP)
+        error(['Operator requires at least ' num2str(2*BP) ' grid points']);
+    end
+
     H_U=[0.751e3 / 0.3456e4 0.661e3 / 0.3456e4 -0.515e3 / 0.3456e4 0.5e1 / 0.128e3; 0.661e3 / 0.3456e4 0.1405e4 / 0.1152e4 -0.3e1 / 0.128e3 0.29e2 / 0.3456e4; -0.515e3 / 0.3456e4 -0.3e1 / 0.128e3 0.989e3 / 0.1152e4 0.149e3 / 0.3456e4; 0.5e1 / 0.128e3 0.29e2 / 0.3456e4 0.149e3 / 0.3456e4 0.3407e4 / 0.3456e4;];
 
 
--- a/+sbp/+implementations/d2_blocknorm_6.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d2_blocknorm_6.m	Fri Sep 09 11:03:13 2016 +0200
@@ -1,4 +1,10 @@
 function [H, HI, D1, D2, e_1, e_m, M, Q, S_1, S_m] = d2_blocknorm_6(m,h)
+    
+    BP = 6;
+    if(m<2*BP)
+        error(['Operator requires at least ' num2str(2*BP) ' grid points']);
+    end
+
     H_U=[0.8489084265971e13 / 0.45952647390720e14 0.24636450459943e14 / 0.98469958694400e14 -0.2796787072531e13 / 0.12308744836800e14 0.2793599068823e13 / 0.14360202309600e14 -0.66344569931569e14 / 0.689289710860800e15 0.3784697867191e13 / 0.137857942172160e15; 0.24636450459943e14 / 0.98469958694400e14 0.27815394775103e14 / 0.19693991738880e14 -0.445601472229e12 / 0.861612138576e12 0.3896159037731e13 / 0.17232242771520e14 -0.866505556741e12 / 0.27571588434432e14 -0.25625418493681e14 / 0.689289710860800e15; -0.2796787072531e13 / 0.12308744836800e14 -0.445601472229e12 / 0.861612138576e12 0.31409405327129e14 / 0.17232242771520e14 -0.1595539040819e13 / 0.3446448554304e13 0.2651608170899e13 / 0.17232242771520e14 0.1434714163381e13 / 0.43080606928800e14; 0.2793599068823e13 / 0.14360202309600e14 0.3896159037731e13 / 0.17232242771520e14 -0.1595539040819e13 / 0.3446448554304e13 0.6984350202787e13 / 0.5744080923840e13 -0.62662743973e11 / 0.861612138576e12 -0.435331581619e12 / 0.12308744836800e14; -0.66344569931569e14 / 0.689289710860800e15 -0.866505556741e12 / 0.27571588434432e14 0.2651608170899e13 / 0.17232242771520e14 -0.62662743973e11 / 0.861612138576e12 0.20320736807807e14 / 0.19693991738880e14 0.1368363924007e13 / 0.98469958694400e14; 0.3784697867191e13 / 0.137857942172160e15 -0.25625418493681e14 / 0.689289710860800e15 0.1434714163381e13 / 0.43080606928800e14 -0.435331581619e12 / 0.12308744836800e14 0.1368363924007e13 / 0.98469958694400e14 0.27414523542149e14 / 0.27571588434432e14;];
 
 
--- a/+sbp/+implementations/d2_blocknorm_8.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d2_blocknorm_8.m	Fri Sep 09 11:03:13 2016 +0200
@@ -1,5 +1,11 @@
 function [H, HI, D1, D2, e_1, e_m, M, Q, S_1, S_m] = d2_blocknorm_8(m,h)
     % Eighth order
+    
+    BP = 8;
+    if(m<2*BP)
+        error(['Operator requires at least ' num2str(2*BP) ' grid points']);
+    end
+    
     e_1=zeros(m,1);e_1(1)=1;
     e_m=zeros(m,1);e_m(m)=1;
 
--- a/+sbp/+implementations/d2_variable_4.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d2_variable_4.m	Fri Sep 09 11:03:13 2016 +0200
@@ -1,4 +1,10 @@
 function [H, HI, D1, D2, e_l, e_r, d_l, d_r] = d2_variable_4(m,h)
+    
+    BP = 4;
+    if(m<2*BP)
+        error(['Operator requires at least ' num2str(2*BP) ' grid points']);
+    end
+
     N = m;
 
     H = speye(N);
--- a/+sbp/+implementations/d4_4.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d4_4.m	Fri Sep 09 11:03:13 2016 +0200
@@ -27,6 +27,11 @@
 
     % Vi b?rjar med normen. Notera att alla SBP operatorer delar samma norm,
     % vilket ?r n?dv?ndigt f?r stabilitet
+    
+    BP = 6;
+    if(m<2*BP)
+        error(['Operator requires at least ' num2str(2*BP) ' grid points']);
+    end
 
     H=diag(ones(m,1),0);
     H_U=[0.35809e5 / 0.100800e6 0 0 0 0 0; 0 0.13297e5 / 0.11200e5 0 0 0 0; 0 0 0.5701e4 / 0.5600e4 0 0 0; 0 0 0 0.45109e5 / 0.50400e5 0 0; 0 0 0 0 0.35191e5 / 0.33600e5 0; 0 0 0 0 0 0.33503e5 / 0.33600e5;];
--- a/+sbp/+implementations/d4_6.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d4_6.m	Fri Sep 09 11:03:13 2016 +0200
@@ -25,6 +25,11 @@
 
     % Vi b?rjar med normen. Notera att alla SBP operatorer delar samma norm,
     % vilket ?r n?dv?ndigt f?r stabilitet
+    
+    BP = 8;
+    if(m<2*BP)
+        error(['Operator requires at least ' num2str(2*BP) ' grid points']);
+    end
 
     H=diag(ones(m,1),0);
     H_U=[0.318365e6 / 0.1016064e7 0 0 0 0 0 0 0; 0 0.145979e6 / 0.103680e6 0 0 0 0 0 0; 0 0 0.139177e6 / 0.241920e6 0 0 0 0 0; 0 0 0 0.964969e6 / 0.725760e6 0 0 0 0; 0 0 0 0 0.593477e6 / 0.725760e6 0 0 0; 0 0 0 0 0 0.52009e5 / 0.48384e5 0 0; 0 0 0 0 0 0 0.141893e6 / 0.145152e6 0; 0 0 0 0 0 0 0 0.1019713e7 / 0.1016064e7;];
--- a/+sbp/+implementations/d4_compatible_2.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d4_compatible_2.m	Fri Sep 09 11:03:13 2016 +0200
@@ -25,6 +25,11 @@
 
     % Vi b?rjar med normen. Notera att alla SBP operatorer delar samma norm,
     % vilket ?r n?dv?ndigt f?r stabilitet
+    
+    BP = 1;
+    if(m<2*BP)
+        error(['Operator requires at least ' num2str(2*BP) ' grid points']);
+    end
 
     H=diag(ones(m,1),0);H(1,1)=1/2;H(m,m)=1/2;
 
--- a/+sbp/+implementations/d4_compatible_4.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d4_compatible_4.m	Fri Sep 09 11:03:13 2016 +0200
@@ -25,6 +25,11 @@
 
     % Vi b?rjar med normen. Notera att alla SBP operatorer delar samma norm,
     % vilket ?r n?dv?ndigt f?r stabilitet
+    
+    BP = 6;
+    if(m<2*BP)
+        error(['Operator requires at least ' num2str(2*BP) ' grid points']);
+    end
 
     H=diag(ones(m,1),0);
     H_U=[0.3e1 / 0.11e2 0 0 0 0 0; 0 0.2125516311e10 / 0.1311004640e10 0 0 0 0; 0 0 0.278735189e9 / 0.1966506960e10 0 0 0; 0 0 0 0.285925927e9 / 0.163875580e9 0 0; 0 0 0 0 0.1284335339e10 / 0.1966506960e10 0; 0 0 0 0 0 0.4194024163e10 / 0.3933013920e10;];
--- a/+sbp/+implementations/d4_compatible_6.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d4_compatible_6.m	Fri Sep 09 11:03:13 2016 +0200
@@ -25,6 +25,11 @@
 
     % Vi b?rjar med normen. Notera att alla SBP operatorer delar samma norm,
     % vilket ?r n?dv?ndigt f?r stabilitet
+    
+    BP = 8;
+    if(m<2*BP)
+        error(['Operator requires at least ' num2str(2*BP) ' grid points']);
+    end
 
     H=diag(ones(m,1),0);
     H_U=[0.7493827e7 / 0.25401600e8 0 0 0 0 0 0 0; 0 0.5534051e7 / 0.3628800e7 0 0 0 0 0 0; 0 0 0.104561e6 / 0.403200e6 0 0 0 0 0; 0 0 0 0.260503e6 / 0.145152e6 0 0 0 0; 0 0 0 0 0.43237e5 / 0.103680e6 0 0 0; 0 0 0 0 0 0.514081e6 / 0.403200e6 0 0; 0 0 0 0 0 0 0.3356179e7 / 0.3628800e7 0; 0 0 0 0 0 0 0 0.25631027e8 / 0.25401600e8;];
--- a/+sbp/+implementations/d4_compatible_halfvariable_2.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d4_compatible_halfvariable_2.m	Fri Sep 09 11:03:13 2016 +0200
@@ -26,6 +26,11 @@
 
     % Vi b?rjar med normen. Notera att alla SBP operatorer delar samma norm,
     % vilket ?r n?dv?ndigt f?r stabilitet
+    
+    BP = 1;
+    if(m<2*BP)
+        error(['Operator requires at least ' num2str(2*BP) ' grid points']);
+    end
 
     H=diag(ones(m,1),0);H(1,1)=1/2;H(m,m)=1/2;
 
--- a/+sbp/+implementations/d4_compatible_halfvariable_4.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d4_compatible_halfvariable_4.m	Fri Sep 09 11:03:13 2016 +0200
@@ -12,6 +12,11 @@
     %m=20; %problemstorlek
     %h=1/(m-1);
     %h=1;
+    
+    BP = 4;
+    if(m<2*BP)
+        error(['Operator requires at least ' num2str(2*BP) ' grid points']);
+    end
 
     c=ones(m,1);
 
--- a/+sbp/+implementations/d4_compatible_halfvariable_6.m	Fri Sep 09 10:41:31 2016 +0200
+++ b/+sbp/+implementations/d4_compatible_halfvariable_6.m	Fri Sep 09 11:03:13 2016 +0200
@@ -25,6 +25,11 @@
     % with the unknown stored as c(1), c(2), ..., c_m
     % x=1:h:m*h;x=x';
     % c=x.^0;
+    
+    BP = 6;
+    if(m<2*BP)
+        error(['Operator requires at least ' num2str(2*BP) ' grid points']);
+    end
 
 
     H=diag(ones(m,1),0);