effect of fiber losses,GVD and SPM

hello.can anybody help me to solve my problem. actually i use numerical method (split step fourier method) in matlab to prove the effect of fiber losses, dispersion and non-linearity in optical soliton and also need to compare that result with optisystem. actually, i already got the result from optisystem for fiber losses, dispersion and SPM. i compared the effect of fiber losses (alpha), GVD (beta2), and SPM (gamma) based on the 3 physical length. (i picked 10km, 20km, and 30km).but here, i need to tally the result with matlab (split step fourier method) n must be the same result with optisystem. i try to change the coding, but it failed. since i picked 3 physical length in optisystem result, so i need to setup the same physical length in matlab coding to test the effect of fiber losses, GVD,and SPM.. i hope you guys help me to solve this problem…:( here i attached the coding from matlab. i took this coding in computational photonics (MAREK S WARTAK) and edit some of the part.