tridiagonal array with loops in matlab

To generate a tridiagonal matrix in MATLAB, one approach is to use loops to fill the matrix with the appropriate values. Here is a sample algorithm for creating a tridiagonal matrix:

main.m
% define matrix size and values
n = 5; % size of the matrix
a = 1; % lower diagonal value
b = 2; % main diagonal value
c = 3; % upper diagonal value

% initialize matrix with zeros
A = zeros(n,n);

% fill in the diagonals
for i=1:n
    for j=1:n
        if i == j
            A(i,j) = b; % main diagonal
        elseif abs(i-j) == 1
            A(i,j) = a; % lower/upper diagonal
        end
    end
end
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In this code, the matrix size n and the values a, b, and c are defined. The matrix A is then initialized with zeros. Two loops are used to fill in the matrix, with the if statement checking whether each element should be in the lower/upper diagonal (a) or the main diagonal (b). The abs(i-j) statement is used to check whether the element is in the lower or upper diagonal.

This algorithm can be extended to larger matrices by adjusting the value of n, and changing the values of a, b, and c to reflect different patterns.