GAUS JORDAN MATLAB

% Code from "Gauss elimination and Gauss Jordan methods using MATLAB"

% https://www.youtube.com/watch?v=kMApKEKisKE

a = [3 4 -2 2 2

    4 9 -3 5 8

    -2 -3 7 6 10

    1 4 6 7 2];

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%Gauss elimination method [m,n)=size(a);

[m,n]=size(a);

for j=1:m-1

    for z=2:m

        if a(j,j)==0

            t=a(j,:);a(j,:)=a(z,:);

            a(z,:)=t;

        end

    end

    for i=j+1:m

        a(i,:)=a(i,:)-a(j,:)*(a(i,j)/a(j,j));

    end

end

x=zeros(1,m);

for s=m:-1:1

    c=0;

    for k=2:m

        c=c+a(s,k)*x(k);

    end

    x(s)=(a(s,n)-c)/a(s,s);

end

disp('Gauss elimination method:');

a

x'

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% Gauss-Jordan method

[m,n]=size(a);

for j=1:m-1

    for z=2:m

        if a(j,j)==0

            t=a(1,:);a(1,:)=a(z,:);

            a(z,:)=t;

        end

    end

    for i=j+1:m

        a(i,:)=a(i,:)-a(j,:)*(a(i,j)/a(j,j));

    end

end

for j=m:-1:2

    for i=j-1:-1:1

        a(i,:)=a(i,:)-a(j,:)*(a(i,j)/a(j,j));

    end

end

for s=1:m

    a(s,:)=a(s,:)/a(s,s);

    x(s)=a(s,n);

end

disp('Gauss-Jordan method:');

a

x'