create operation count for gauss jordan in matlab in matlab

To create an operation count for Gauss Jordan elimination in MATLAB, we can implement the algorithm in code and use counters to keep track of the number of arithmetic operations being performed. Here's an example implementation:

main.m
function [x, ops] = gauss_jordan(A, b)
% Inputs:
% A: Coefficient matrix
% b: Right-hand side vector
% Outputs:
% x: Solution vector
% ops: Total number of arithmetic operations performed

[m, n] = size(A);
if m ~= n || size(b, 2) ~= 1 || size(b, 1) ~= m
    error('Invalid input dimensions');
end

% Augment matrix with right-hand side vector
A = [A b];

ops = 0; % Initialize operation count
for k = 1:m % Iterate over rows
    ops = ops + n; % n subtractions and n multiplications
  
    % Partial pivoting
    [~, p] = max(abs(A(k:m, k)));
    p = p + k - 1;
    if p ~= k
        A([k,p], :) = A([p,k], :);
        ops = ops + n; % n swaps
    end
    
    % Normalize pivot row
    A(k, :) = A(k, :) / A(k, k);
    ops = ops + n - 1; % n divisions
    
    % Eliminate entries below pivot
    for i = k+1:m
        A(i, :) = A(i, :) - A(i, k)*A(k, :);
        ops = ops + 2*n - 1; % n multiplications and n subtractions
    end
end

for k = m:-1:2 % Iterate over rows backwards
    % Eliminate entries above pivot
    for i = k-1:-1:1
        A(i, :) = A(i, :) - A(i, k)*A(k, :);
        ops = ops + 2*n - 1; % n multiplications and n subtractions
    end
end

x = A(:, end); % Extract solution vector
ops = ops + m; % m assignments

end
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In this implementation, the ops variable keeps track of the total number of additions, subtractions, multiplications, divisions, and assignments performed during the algorithm. By calling this function with a given matrix A and right-hand side vector b, we can obtain the solution x as well as the operation count ops.

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