solve_tridiag.m

function [x] = solve_tridiag(ud,uo,lo,b)
%Takes the main diagnol of the upper matrix and the off
%diagnol of the lower and upper matrices and the vector b.
%Input - solution for lu_tridiag function
%Output - x vector (Ax = B)

M = zeros(1,length(ud)); % initializing the vector
 
for n = 1:(length(ud)-1)
    M(1)=b(1);
    M(n+1)= b(n+1)-(lo(n)*M(n));
end
x=zeros(1,length(ud)); % initializing x vector

for k =(length(ud):-1:2)
    x(length(ud))=M(length(ud))/ud(length(ud));
    x(k-1)= (M(k-1)-(uo(k-1)*x(k)))/(ud(k-1));
end