MATLAB: How to label faces and edges of the model using dsg in pde toolbox

pde

I have constructed a two-dimensional model with multiple subdomains, each subdomain has different coefficients for the underlying PDE. Sometimes there are four faces, and sometimes there are five, with the one extra subdomain having its own set of coefficients again. How do I make sure that the face and edge labels refer to the same subdomain with or without the extra subdomains, so that specifyCoefficients() and applyBoundaryConditions() can assign the correct set to the corresponding region using the face and edge labels respectively?

Best Answer

The only way that I know to make the labels refer to things reproducibly is to construct your geometry using a parametrized geometry function.

Good luck,

Alan Weiss

MATLAB mathematical toolbox documentation

Related Solutions

MATLAB: PDETOOL – How to find the label of domain

I don't know how to choose the label numbers in a geometry except by creating the geometry using a Geometry Function. See Geometry Function Example with Subdomains and a Hole.

Alan Weiss

MATLAB mathematical toolbox documentation

MATLAB: How to set space-varying boundary conditions

You can use applyBoundaryCondition. You just have to create a mesh for the geometry.

% Create a 3-dimensional PDE Model
model = createpde(3);
% Construct the Geometry
[x,y,z] = meshgrid([-3:0.25:3],[-2:0.25:2],[-1:0.25:1]);
% Create the convex hull.
x = x(:);
y = y(:);
z = z(:);
K = convhull(x,y,z);
% Put the data in the correct shape for |geometryFromMesh|.
nodes = [x';y';z'];
elements = K';
% Create a PDE model and import the mesh.
geometryFromMesh(model,nodes,elements);
% Plot geometry
figure
pdegplot(model,'FaceLabels','on')
title('Bracket with Face Labels')
% Now the new stuff
generateMesh(model)
ufun = @(region,state)[region.x.^2;region.x.^2 + region.y.^2;region.x.^2 + region.y.^2 - region.z]
applyBoundaryCondition(model,'dirichlet','Face',6,'u',ufun,'Vectorized','on')
specifyCoefficients(model,'m',0,'d',0,'c',1,'a',0,'f',[1;2;3]);
results = solvepde(model);
pdeplot3D(model,'ColorMapData',results.NodalSolution(:,1))

Alan Weiss

MATLAB mathematical toolbox documentation

Best Answer

Related Solutions

MATLAB: PDETOOL – How to find the label of domain

MATLAB: How to set space-varying boundary conditions

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