view +sbp/+implementations/d2_variable_2.m @ 958:72cd29107a9a feature/poroelastic

Temporary changes in multiblock.DiffOp. Change traction operators in Elastic2dvariable to be true boundary operators. But adjoint FD conv test fails for dirichlet BC so need to debug!
author Martin Almquist <malmquist@stanford.edu>
date Wed, 05 Dec 2018 18:58:10 -0800
parents b758d1cf4c8e
children e54c2f54dbfe
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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, B] = 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');
        B = HI*M;
    end
    D2 = @D2_fun;

end