I am afraid that the question is not clear due to bad formatting so I'll to explain a bit better
(sorry for double post)
I need a method for solving a linear system (x1..xn) of type
where A is a tridiagonal matrix
. x x x
. . x x x
with (generic) structure
x2*k21 x3*(k22+k23/(x1+x2+..xn) x4*k24
and so on, size N about 400 x 400 (sparse),
I am unable to find a solution which allow to use Thomas or similar efficient methods
cause diagonal elements contains K/(x1+x2+...+xn) which require separate processing,
what am I missing here ?
Is there any simple solution for these systems ?
Thanks for help.