I took this code from i have a viva tomorrow plz explain me the code

clear X A=input ('please enter the Matrix :') b=[8;4;5]

tol = 1.e-8; maxiter = 100; relerr = inf; niter = 1; S = diag( diag(A) ); display (S) T = S - A; display (T)

X(:,1) = zeros(size(b)); while relerr > tol & niter< maxiter, X(:,niter+1) = S \ (b+T*X(:,niter)); relerr = norm(X(:,niter+1)-X(:,niter),inf)/norm(X(:,niter+1),inf); niter = niter+1; end display (niter) display (X(:,niter))

Answer 1

[Thomas]

Dont know if this code works.. the function of each line is inthe comments i.e after the %

 clear X   % clears the variable X

A=input ('please enter the Matrix :')  % asks the user to input the matrix

% define variable:
b=[8;4;5]  % define b

tol = 1.e-8;  % define tolerance

maxiter = 100;  % define maximum number of iterations
relerr = inf;  % define relative error

niter = 1; 

% cal
S = diag( diag(A) );  % finds the diagonal matrix of the diagonal elements of input

display (S)      % displays matrix S from previous step

T = S - A;      % create a new matrix T
display (T)     % displays matrix t from previous step

X(:,1) = zeros(size(b));   % for a matrix the sixe of b insert all zeroes

% while the relative error is > the tolerance and interation no < max number of iterations
while relerr > tol & niter< maxiter,             
    X(:,niter+1) = S \ (b+T*X(:,niter));  % X is calculated as
    relerr = norm(X(:,niter+1)-X(:,niter),inf)/norm(X(:,niter+1),inf); % new relative error is 
    niter = niter+1;  % iteration number is incremented to step through the loop
end

display (niter)       % display the iteration number
display (X(:,niter))  % display the output

Answer 2

[FYP]

thanks mate