PDEPE function - BCFUN error

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Sanley Guerrier 2023-11-20

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2049922-pdepe-function-bcfun-error

评论： Sanley Guerrier 2023-11-21

采纳的回答： Torsten

在 MATLAB Online 中打开

Hello all,

Can someone help me with the BCFUN error?

Thank you!

Error using pdepe

Unexpected output of BCFUN. For this problem BCFUN must return four column vectors of length 1.

Error in run_model (line 53)

sol = pdepe(0, @pdefun, @icfun, @bcfun, z_mesh, t_mesh);

Error in driver (line 58)

[z_mesh, t_mesh, T] = run_model(alpha, z_sensor, time, temp, env, hc, k, eps, sigma, A, Hs);

function [z_mesh, t_mesh, T] = run_model(alpha, z_sensor, time, t_mesh, temp, env, hc, k, eps, sigma, A,Hs)
% Create the time mesh using the measurement times [days].
% t_mesh is shifted to start at 0.
t_mesh = convertTo(time, 'datenum') - convertTo(time(1), 'datenum');
% Create the space mesh using even spacing between the top and 
% bottom sensors, plus the locations of the intermediate sensors.
z_mesh = unique([linspace(z_sensor(1), z_sensor(end), 100), z_sensor]);
% Solve the heat equation.
sol = pdepe(0, @pdefun, @icfun, @bcfun, z_mesh, t_mesh);
% Extract the first solution component as T.
T = sol(:,:,1);
%------------------------------------------------
% pdefun
%------------------------------------------------
    function [c, f, s] = pdefun(z, t, T, dTdz)
        c = 1;
        f = alpha * dTdz;
        s = 0;
    end
%------------------------------------------------
% icfun
%
% Notes:
% o The inital temperature profile is given by
%   interpolating the initial field data.
%------------------------------------------------
    function T0 = icfun(z)
        T0 = interp1(z_sensor, temp(1, :), z, 'linear');
    end
%------------------------------------------------
% bcfun
%
% Notes:
% o The boundary conditions through time are 
%   given by the flux and temperature at the bottom sensors. 
%------------------------------------------------
    function [ptop, qtop, pbot, qbot] = bcfun(ztop, Ttop, zbot, Tbot,t)
        % hc and Hs are vectors
        ptop = hc.*(Ttop-env(:,1))+ eps*sigma*Ttop^4-A*Hs;
        qtop = k;
        pbot = Tbot - interp1(t_mesh, temp(:,6), t, 'linear');
        qbot = 0;
    end
end

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采纳的回答

Torsten 2023-11-20

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2049922-pdepe-function-bcfun-error#answer_1356762

编辑：Torsten 2023-11-20

在 MATLAB Online 中打开

Use

function [ptop, qtop, pbot, qbot] = bcfun(ztop, Ttop, zbot, Tbot,t)
% hc and Hs are vectors
ptop = hc.*(Ttop-env(:,1))+ eps*sigma*Ttop^4-A*Hs;
qtop = k;
pbot = Tbot - interp1(t_mesh, temp(:,6), t, 'linear');
qbot = 0;
size(ptop)
end