function b = solvet(u, d, l, b)
% usage: b = solvet(u, d, l, b)
%
% Solve tridiagonal system using the output
% from decomt.m
%
% Inputs
%	u	upper diagonal of U
%	d	main diagonal of U
%	l	subdiagonal of L 
%	b	right-hand-side vector, overwritten by solution
% Output
%	b	solution

n = length(b);
%
% solve L*y=b
for i=2:n,
    b(i) = b(i) - l(i-1)*b(i-1);
b,
end;
%
% solve U*x=y
b(n) = b(n)/d(n);
b,
for i=n-1:-1:1,
    b(i) = (b(i) - u(i)*b(i+1))/d(i);
b,
end;