Mercurial > repos > public > sbplib
view +sbp/+implementations/d2_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 | 8b8672134be8 |
children |
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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=sparse(m,1);e_1(1)=1; e_m=sparse(m,1);e_m(m)=1; H=(speye(m,m));H(1,1)=0.5;H(m,m)=0.5; H=h*H; HI=inv(H); 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 = D1/h; Q = H*D1 + 1/2*(e_1*e_1') - 1/2*(e_m*e_m'); diags = -1:1; stencil = [1 -2 1]; D2 = stripeMatrix(stencil, diags, m); D2(1,1) = 1; D2(1,2) = -2; D2(1,3) = 1; D2(m,m-2) = 1; D2(m,m-1) = -2; D2(m,m) = 1; D2 = D2/h^2; S_U = [-3/2, 2, -1/2]/h; S_1 = sparse(1,m); S_1(1:3) = S_U; S_m = sparse(1,m); S_m(m-2:m) = fliplr(-S_U); M = -H*D2-e_1*S_1+e_m*S_m; S_1 = S_1'; S_m = S_m'; end