30 lines
556 B
Matlab
30 lines
556 B
Matlab
function b = Al3(L, b)
|
|
% Algorithm 3: Forward Substitution
|
|
% b = Alg3_forward_substitution(L, b) overwrites b with the solution to
|
|
% Lx = b.
|
|
|
|
[m, n] = size(L);
|
|
|
|
if m ~= n
|
|
error('Matrix is not square!')
|
|
end
|
|
|
|
if length(b) ~= m
|
|
error('Vector b has wrong length!')
|
|
end
|
|
|
|
if det(L) < eps
|
|
error("Matrix is not nonsingular!")
|
|
end
|
|
|
|
% The following algorithm is based on the Algrotihm 3.1.1 from [2].
|
|
|
|
% b(m, :) so that matrices are also accepted
|
|
b(1, :) = b(1, :)/L(1,1);
|
|
for i = 2:m
|
|
b(i, :) = (b(i, :) - L(i, 1:i-1)*b(1:i-1, :))/L(i, i);
|
|
end
|
|
|
|
end
|
|
|