Hi Santos
The "()-indexing must appear last in an index expression," occurs because MATLAB does not support indexing with parentheses. Instead, use curly braces {} to index into a cell array.
Here is how the updated code will look like:
xbar = 10; % Number of beams in the space truss
rigidlocal = cell(xbar, 1); % Initialize cell array to store stiffness matrices
for i = 1:xbar
rigidlocal{i} = zeros(4); % Initialize a 4x4 matrix for each beam
rigidlocal{i}(1, 4) = -1;
rigidlocal{i}(4, 1) = rigidlocal{i}(1, 4);
rigidlocal{i}(1, 1) = 1;
rigidlocal{i}(4, 4) = rigidlocal{i}(1, 1);
% Display the matrix
fprintf('Stiffness matrix for beam %d:\n', i);
disp(rigidlocal{i});
end
