Mercurial > repos > public > sbplib
view +sbp/+implementations/d2_variable_2.m @ 1301:8978521b0f06 default
Fix incorrect package name.
author | Vidar Stiernström <vidar.stiernstrom@it.uu.se> |
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date | Wed, 08 Jul 2020 19:11:04 +0200 |
parents | ded4156e53e2 |
children | b758d1cf4c8e |
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function [H, HI, D1, D2, e_l, e_r, d1_l, d1_r] = d2_variable_2(m,h) BP = 1; if(m<2*BP) error(['Operator requires at least ' num2str(2*BP) ' grid points']); end % Norm Hv = ones(m,1); Hv(1) = 1/2; Hv(m:m) = 1/2; Hv = h*Hv; H = spdiag(Hv, 0); HI = spdiag(1./Hv, 0); % Boundary operators e_l = sparse(m,1); e_l(1) = 1; e_r = rot90(e_l, 2); d1_l = sparse(m,1); d1_l(1:3) = 1/h*[-3/2 2 -1/2]; d1_r = -rot90(d1_l, 2); % D1 operator diags = -1:1; stencil = [-1/2 0 1/2]; D1 = stripeMatrix(stencil, diags, m); D1(1,1)=-1;D1(1,2)=1;D1(m,m-1)=-1;D1(m,m)=1; D1(m,m-1)=-1;D1(m,m)=1; D1=D1/h; %Q=H*D1 + 1/2*(e_1*e_1') - 1/2*(e_m*e_m'); M=sparse(m,m); scheme_width = 3; scheme_radius = (scheme_width-1)/2; r = (1+scheme_radius):(m-scheme_radius); function D2 = D2_fun(c) Mm1 = -c(r-1)/2 - c(r)/2; M0 = c(r-1)/2 + c(r) + c(r+1)/2; Mp1 = -c(r)/2 - c(r+1)/2; M(r,:) = spdiags([Mm1 M0 Mp1],0:2*scheme_radius,length(r),m); M(1:2,1:2)=[c(1)/2 + c(2)/2 -c(1)/2 - c(2)/2; -c(1)/2 - c(2)/2 c(1)/2 + c(2) + c(3)/2;]; M(m-1:m,m-1:m)=[c(m-2)/2 + c(m-1) + c(m)/2 -c(m-1)/2 - c(m)/2; -c(m-1)/2 - c(m)/2 c(m-1)/2 + c(m)/2;]; M=M/h; D2=HI*(-M-c(1)*e_l*d1_l'+c(m)*e_r*d1_r'); end D2 = @D2_fun; end