Why does my code say incorrect number or types of inputs or outputs for function specifyCoefficients?

specifyCoefficients(smodel,'m', 1520,'d', 0,'c', 1,'a', 0, 'f', 0, 'Face', 1:3);

This is the code I'm trying to run with Matlab's PDE toolbox, but it says "incorrect number or types of inputs or outputs for function specifyCoefficients."

How do I fix the code?

Answer 1

[Walter Roberson]

There is no 'Face' parameter for that call.

[Marcus]

It still says the same error message after I changed it to:

specifyCoefficients(smodel, 'm', 1520, 'd', 0, 'c', 343, 'a', 0, 'f', 0);

[Walter Roberson]

All I can guess is that smodel is not a valid PDEModel model object.

[Marcus]

Could the numbers I'm inputting be incorrect?

[Walter Roberson]

I think if the values of the parameters are somehow unrealistic, that you would get a different message.

Time to use the debugger.

dbstop in  specifyCoefficients
    specifyCoefficients(smodel,'m', 1520,'d', 0,'c', 1,'a', 0, 'f', 0, 'Face', 1:3);

and step through, looking at why the parameters are rejected.

[Marcus]

When I type the dbstop command in, the same error message shows up. Does it matter if I use '' or "" when I define the coefficients? And does the order of the coefficients matter?

[Torsten]

Can you run the following worked-out example from the PDE toolbox ?

Maybe you created a function with name "specifyCoefficients.m" in your working directory which overrides the built-in MATLAB function ?

model = createpde();
geometryFromEdges(model,@circleg);
figure 
pdegplot(model,"EdgeLabels","on"); 
axis equal
applyBoundaryCondition(model,"dirichlet", ...
                             "Edge",1:model.Geometry.NumEdges, ...
                             "u",0);
specifyCoefficients(model,"m",0,"d",0,"c",1,"a",0,"f",1);
hmax = 0.1;
generateMesh(model,"Hmax",hmax);
figure
pdemesh(model); 
axis equal
results = solvepde(model);
u = results.NodalSolution;
pdeplot(model,"XYData",u)
title("Numerical Solution");
xlabel("x")
ylabel("y")
hmax = 0.1;
error = [];
err = 1;
while err > 5e-7 % run until error <= 5e-7
    generateMesh(model,"Hmax",hmax); % refine mesh
    results = solvepde(model);
    u = results.NodalSolution;
    p = model.Mesh.Nodes;
    exact = (1 - p(1,:).^2 - p(2,:).^2)/4; 
    err = norm(u - exact',inf); % compare with exact solution
    error = [error err]; % keep history of err
    hmax = hmax/2;
end
plot(error,"rx","MarkerSize",12);
ax = gca;
ax.XTick = 1:numel(error);
title("Error History");
xlabel("Iteration");
ylabel("Norm of Error");
figure
pdemesh(model); 
axis equal
figure
pdeplot(model,"XYData",u)
title("Numerical Solution");
xlabel("x")
ylabel("y")
p = model.Mesh.Nodes;
exact = (1 - p(1,:).^2 - p(2,:).^2)/4;
pdeplot(model,"XYData",u - exact')
title("Error");
xlabel("x")
ylabel("y")

[Walter Roberson]

The dbstop is not intended as a cure for the problem. The dbstop tells the system that you want to debug specifyCoefficients from the beginning, and after you give that command, calling specifyCoefficients should stop in the debugger.