How to fill a triangle in an circular mesh in pdeplot?

Hello sir

I have an circular mesh. Inside the mesh I have another circle.Now how to fill the circle? In the circle there are 4 triangle element and the cicular mesh have 268 elements. Please help me.

Answer 1

[AKennedy]

From what you have described, here's how I would approach it

1. Identify the Inner Circle Elements: Determine which elements (triangles) belong to the inner circle.
2. Plot the Mesh: Use the patch function to plot the mesh and fill the inner circle.

% Sample data: Adjust these arrays based on your actual mesh data
% Nodes of the mesh (example coordinates)
nodes = [
    0, 0;
    1, 0;
    0.5, 0.5;
    0, 1;
    % ... (add more nodes as needed)
];

% Connectivity of the mesh elements (example indices)
elements = [
    1, 2, 3;
    1, 3, 4;
    % ... (add more elements as needed)
];

% Elements belonging to the inner circle
inner_circle_elements = [1, 2, 3, 4]; % Example indices of inner circle elements

% Plot the full mesh
figure;
hold on;
for i = 1:size(elements, 1)
    % Extract node indices for the current element
    node_indices = elements(i, :);
    
    % Get the coordinates for the nodes of the element
    x = nodes(node_indices, 1);
    y = nodes(node_indices, 2);
    
    % Plot the element
    patch(x, y, 'w'); % 'w' for white; adjust color as needed
end

% Fill the inner circle elements
for i = inner_circle_elements
    % Extract node indices for the current inner circle element
    node_indices = elements(i, :);
    
    % Get the coordinates for the nodes of the element
    x = nodes(node_indices, 1);
    y = nodes(node_indices, 2);