Hey, i've been trying to find a better fit for a correlation, the numbers i'm dealing with are really small and when i try to solve for the coefficients using the inverse function on the matrices in Matlab i get this error: Warning: Matrix is close to singular or badly scaled. Results may be inaccurate. RCOND = 5.541639e-25. I tried solving the inverted matrix in excel and the results didn't make much sense either! is there an other way to solve this problem? I really can't solve it by hand it'll take me ages. i'm open to any suggestion... J.