lu_tridiag.m

function [ud, uo, lo ] = lu_tridiag( e,f,g )
%create matrixs A and B
A=diag(e,-1)+ diag(f)+diag(g,1);
B=eye(length(f));

for i=1:length(e)
X=A(i+1,i)/A(i,i);
A(i+1,i)= (-e(i)/f(i))*f(i)+e(i);
A(i+1,i+1)= (-X)*g(i)+f(i+1);
B(i+1,i)=X;
    ud(1)=A(1,1);
    ud(i+1)= A(i+1,i+1);
    uo(i)=A(i,i+1);
    lo(i)=B(i+1,i);
end
%displays function results 
disp(ud)
disp(uo)
disp(lo)
end