Question

i need explanation for each line and thank you

% Gauss-Jordan method [m, n]-size (a): for j-1:m-1 for z-2:m if a (j,1)0 end end for i-j+1:m end end for j-m:-1:2 for i*)-1:-1:1 end end for s=1:m x (s)-a(s,n); end disp('Guass-Jordan method: '

Answer 1

%% Gauss-Jordan method
% this code creates a identity matrix of size m in the first m columns
[m,n] = size(a);
% m is the number of rows in matrix a
% n is the number of columns in matrix a
for j = 1:m-1 % looping from 1 to m-1
for z = 2:m % looping from 2 to m
if a(j,j) == 0
% checking wheter the diagonal element of the matrix a is zero or not
t = a(1,:);
% assiging all the elements of first row to t
a(1,:) = a(z,:);
% assinging the zth rows elements to the first row
a(z,:) = t;
% assinging the first row elements to the zth row
% this process is interchanging rows when the diagonal element is 0
end % end of if condition
end % end of inner for loop
for i = j+1:m % looping from j+1 to m
a(i,:) = a(i,:) - a(j,:)*(a(i,j)/a(j,j));
% updating the ith row elements by subtracting the jth row elemnts
% multiplied by the ith row, ith column element and divided by the
% jth row jth column element from the ith row
end % end of inner for loop
end % end of outer for loop
for j = m:-1:2 % looping from m to 2 in steps of -1
for i = j-1:-1:1 % looping from j-1 to 1 in steps of -1
a(i,:) = a(i,:) - a(j,:)*(a(i,j)/a(j,j));
% updating the ith row elements by subtracting the jth row elemnts
% multiplied by the ith row, ith column element and divided by the
% jth row jth column element from the ith row
end % end of inner for loop
end % end of outer for loop

for s = 1:m % looping from 1 to m
a(s,:) = a(s,:)/a(s,s);
% updating the sth row of a by dividing the sth row by the sth row, sth
% column element
x(s) = a(s,n);
% assigning the sth row, last column of the a matrix to the sth element of
% x
end % end of for loop
disp('Gauss-Jordan method: ');
% command to display in the command window
a
% to display a matrix in the command window
x'
% to display transpose of the x vector in the command window