Mercurial > repos > public > sbplib
diff +sbp/D2VariablePeriodic.m @ 1071:92cb03e64ca4 feature/grids/LaplaceSquared
Merge with default
| author | Jonatan Werpers <jonatan@werpers.com> |
|---|---|
| date | Thu, 20 Sep 2018 12:05:20 +0200 |
| parents | 5ccf6aaf6d6b |
| children | bf2554f1825d |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/+sbp/D2VariablePeriodic.m Thu Sep 20 12:05:20 2018 +0200 @@ -0,0 +1,71 @@ +classdef D2VariablePeriodic < sbp.OpSet + properties + D1 % SBP operator approximating first derivative + H % Norm matrix + HI % H^-1 + Q % Skew-symmetric matrix + e_l % Left boundary operator + e_r % Right boundary operator + D2 % SBP operator for second derivative + M % Norm matrix, second derivative + d1_l % Left boundary first derivative + d1_r % Right boundary first derivative + m % Number of grid points. + h % Step size + x % grid + borrowing % Struct with borrowing limits for different norm matrices + end + + methods + function obj = D2VariablePeriodic(m,lim,order) + + x_l = lim{1}; + x_r = lim{2}; + L = x_r-x_l; + obj.h = L/m; + x = linspace(x_l,x_r,m+1)'; + obj.x = x(1:end-1); + + switch order + + case 6 + [obj.H, obj.HI, obj.D1, obj.D2, obj.e_l,... + obj.e_r, obj.d1_l, obj.d1_r] = ... + sbp.implementations.d2_variable_periodic_6(m,obj.h); + obj.borrowing.M.d1 = 0.1878; + obj.borrowing.R.delta_D = 0.3696; + % Borrowing e^T*D1 - d1 from R + + case 4 + [obj.H, obj.HI, obj.D1, obj.D2, obj.e_l,... + obj.e_r, obj.d1_l, obj.d1_r] = ... + sbp.implementations.d2_variable_periodic_4(m,obj.h); + obj.borrowing.M.d1 = 0.2505765857; + + obj.borrowing.R.delta_D = 0.577587500088313; + % Borrowing e^T*D1 - d1 from R + case 2 + [obj.H, obj.HI, obj.D1, obj.D2, obj.e_l,... + obj.e_r, obj.d1_l, obj.d1_r] = ... + sbp.implementations.d2_variable_periodic_2(m,obj.h); + obj.borrowing.M.d1 = 0.3636363636; + % Borrowing const taken from Virta 2014 + + obj.borrowing.R.delta_D = 1.000000538455350; + % Borrowing e^T*D1 - d1 from R + + otherwise + error('Invalid operator order %d.',order); + end + obj.borrowing.H11 = obj.H(1,1)/obj.h; % First element in H/h, + + obj.m = m; + obj.M = []; + end + function str = string(obj) + str = [class(obj) '_' num2str(obj.order)]; + end + end + + +end