view +util/calc_borrowing.m @ 774:66eb4a2bbb72 feature/grids

Remove default scaling of the system. The scaling doens't seem to help actual solutions. One example that fails in the flexural code. With large timesteps the solutions seems to blow up. One particular example is profilePresentation on the tdb_presentation_figures branch with k = 0.0005
author Jonatan Werpers <jonatan@werpers.com>
date Wed, 18 Jul 2018 15:42:52 -0700
parents d24869abc7cd
children
line wrap: on
line source

function calc_borrowing(m, h)
    default_arg('m',100);
    default_arg('h',1);

    operators = {
        {
            'd4_lonely', getM4_lonely, {
                {4, 'min_boundary_points'},
                {6, 'min_boundary_points'},
                {6, '2'},
                {6, '3'},
                {8, 'min_boundary_points'},
                {8, 'higher_boundary_order'},
            }
        }, {
            'd4_variable', {
                {2},
                {4},
                {6},
            }
        }
        % BORKEN BAD IDEA
    }


    for i = 1:operators
        baseName = operators{i}{1};
        postFixes = operators{i}{2};
        for pf = postFixes
            [a2, a3] = borrowFromD4(m, h, l{:});
        end
    end



    lonely = {
        {4, 'min_boundary_points'},
        {6, 'min_boundary_points'},
        {6, '2'},
        {6, '3'},
        {8, 'min_boundary_points'},
        {8, 'higher_boundary_order'},
    };

    for i = 1:length(lonely)
        l = lonely{i};
        [a2, a3] = d4_lonely(m, h, l{:});
        fprintf('d4_lonely %d %s\n', l{:})
        fprintf('\t  alpha_II = %f\n', a2)
        fprintf('\t alpha_III = %f\n', a3)
        fprintf('\n')
    end

    variable = {
        {2},
        {4},
        {6},
    };

    for i = 1:length(variable)
        l = variable{i};
        [a2, a3] = d4_variable(m, h, l{:});
        fprintf('d4_variable %d\n', l{:})
        fprintf('\t  alpha_II = %f\n', a2)
        fprintf('\t alpha_III = %f\n', a3)
        fprintf('\n')
    end


    %% 4th order non-compatible
    [H, HI, D1, D2, D3, D4, e_1, e_m, M, M4,Q, Q3, S2_1, S2_m, S3_1, S3_m, S_1, S_m] = sbp.higher4(m,h);
    S1 = S_1*S_1'  + S_m*S_m';
    S2 = S2_1*S2_1' + S2_m*S2_m';
    S3 = S3_1*S3_1' + S3_m*S3_m';

    alpha_I  = util.matrixborrow(M4, h^-1*S1  );
    alpha_II  = util.matrixborrow(M4, h*S2  );
    alpha_III = util.matrixborrow(M4, h^3*S3);
    fprintf('4th order non-compatible\n')
    fprintf('alpha_I1:  %.10f\n',alpha_I)
    fprintf('alpha_II:  %.10f\n',alpha_II)
    fprintf('alpha_III: %.10f\n',alpha_III)
    fprintf('\n')


    %% 6th order non-compatible
    [H, HI, D1, D2, D3, D4, e_1, e_m, M, M4,Q, Q3, S2_1, S2_m, S3_1, S3_m, S_1, S_m] = sbp.higher6(m,h);
    S1 = S_1*S_1'  + S_m*S_m';
    S2 = S2_1*S2_1' + S2_m*S2_m';
    S3 = S3_1*S3_1' + S3_m*S3_m';

    alpha_II  = util.matrixborrow(M4, h*S2  );
    alpha_III = util.matrixborrow(M4, h^3*S3);
    fprintf('6th order non-compatible\n')
    fprintf('alpha_II:  %.10f\n',alpha_II)
    fprintf('alpha_III: %.10f\n',alpha_III)
    fprintf('\n')


    %% 2nd order compatible
    [H, HI, D1, D4, e_1, e_m, M4, Q, S2_1, S2_m, S3_1, S3_m, S_1, S_m] = sbp.higher_compatible2(m,h);
    S1 = S_1*S_1'  + S_m*S_m';
    S2 = S2_1*S2_1' + S2_m*S2_m';
    S3 = S3_1*S3_1' + S3_m*S3_m';

    alpha_II  = util.matrixborrow(M4, h*S2  );
    alpha_III = util.matrixborrow(M4, h^3*S3);
    fprintf('2nd order compatible\n')
    fprintf('alpha_II:  %.10f\n',alpha_II)
    fprintf('alpha_III: %.10f\n',alpha_III)
    fprintf('\n')


    %% 4th order compatible
    [H, HI, D1, D4, e_1, e_m, M4, Q, S2_1, S2_m, S3_1, S3_m, S_1, S_m] = sbp.higher_compatible4(m,h);
    S1 = S_1*S_1'  + S_m*S_m';
    S2 = S2_1*S2_1' + S2_m*S2_m';
    S3 = S3_1*S3_1' + S3_m*S3_m';

    alpha_II  = util.matrixborrow(M4, h*S2  );
    alpha_III = util.matrixborrow(M4, h^3*S3);
    fprintf('4th order compatible\n')
    fprintf('alpha_II:  %.10f\n',alpha_II)
    fprintf('alpha_III: %.10f\n',alpha_III)
    fprintf('\n')

    %% 6th order compatible
    [H, HI, D1, D4, e_1, e_m, M4, Q, S2_1, S2_m, S3_1, S3_m, S_1, S_m] = sbp.higher_compatible6(m,h);
    S1 = S_1*S_1'  + S_m*S_m';
    S2 = S2_1*S2_1' + S2_m*S2_m';
    S3 = S3_1*S3_1' + S3_m*S3_m';

    alpha_II  = util.matrixborrow(M4, h*S2  );
    alpha_III = util.matrixborrow(M4, h^3*S3);
    fprintf('6th order compatible\n')
    fprintf('alpha_II:  %.10f\n',alpha_II)
    fprintf('alpha_III: %.10f\n',alpha_III)
    fprintf('\n')





    % Ordinary

    for order = [2 4 6 8 10]
        op = sbp.Ordinary(m,h, order);

        S_1 = op.boundary.S_1;
        S_m = op.boundary.S_m;

        M = op.norms.M;

        S1 = S_1*S_1'  + S_m*S_m';
        alpha  = util.matrixborrow(M, h*S1);
        fprintf('%dth order Ordinary\n', order)
        fprintf('alpha:  %.10f\n', alpha)
        fprintf('\n')
    end




end

function [alpha_II, alpha_III] = d4_lonely(m, h, order, modifier)
    default_arg('modifier', [])
    func = sprintf('sbp.implementations.d4_lonely_%d', order);
    if ~isempty(modifier)
        func = sprintf('%s_%s', func, modifier);
    end
    funcCall = sprintf('%s(%s,%s)', func, toString(m), toString(h));
    [H, HI, D4, e_l, e_r, M4, d2_l, d2_r, d3_l, d3_r, d1_l, d1_r] = eval(funcCall);

    d2d2 = d2_l*d2_l' + d2_r*d2_r';
    alpha_II  = util.matrixborrow(M4, h*d2d2);

    d3d3 = d3_l*d3_l' + d3_r*d3_r';
    alpha_III = util.matrixborrow(M4, h^3*d3d3);
end

function [alpha_II, alpha_III] = d4_variable(m, h, order)
    default_arg('modifier', [])
    func = sprintf('sbp.implementations.d4_variable_%d', order);

    funcCall = sprintf('%s(%s,%s)', func, toString(m), toString(h));
    [H, HI, D1, D2, D4, e_l, e_r, M4, d2_l, d2_r, d3_l, d3_r, d1_l, d1_r] = eval(funcCall);

    d2d2 = d2_l*d2_l' + d2_r*d2_r';
    alpha_II  = util.matrixborrow(M4, h*d2d2);

    d3d3 = d3_l*d3_l' + d3_r*d3_r';
    alpha_III = util.matrixborrow(M4, h^3*d3d3);
end

function [d2_l, d2_r, d3_l, d3_r, M4] = getM4_lonely(m, h, order, modifier)
    fStr = getFunctionCallStr('d4_lonely', {order, modifier}, {m ,h});
    [H, HI, D4, e_l, e_r, M4, d2_l, d2_r, d3_l, d3_r, d1_l, d1_r] = eval(funcCall);
end


% Calculates the borrowing constants for a D4 operator.
% getM4 is a function handle on the form
%  [d2_l, d2_r, d3_l, d3_r, M4] = getM4(m,h)
function [a2, a3] = borrowFromD4(m, h, getM4)
    [d2_l, d2_r, d3_l, d3_r, M4] = getM4(m, h);

    d2d2 = d2_l*d2_l' + d2_r*d2_r';
    a2  = util.matrixborrow(M4, h*d2d2);

    d3d3 = d3_l*d3_l' + d3_r*d3_r';
    a3 = util.matrixborrow(M4, h^3*d3d3);
end


function funcCallStr = getFunctionCallStr(baseName, postFix, parameters)
    default_arg('postFix', [])
    default_arg('parameters', [])

    funcCallStr = sprintf('sbp.implementations.%s', baseName);

    for i = 1:length(postFix)
        if ischar(postFix{i})
            funcCallStr = [funcCallStr '_' postFix{i}];
        else
            funcCallStr = [funcCallStr '_' toString(postFix{i})];
        end
    end

    if isempty(parameters)
        return
    end

    funcCallStr = [funcCallStr '(' toString(parameters{1})];

    for i = 2:length(parameters)
        funcCallStr = [funcCallStr ', ' toString(parameters{i})];
    end

    funcCallStr = [funcCallStr ')';
end