Dispersion relationship for water waves

This script computes the dispersion relationship for water waves

With this function, you can get the value of L (wavelength), k (wave number), sigma(angular frequency), using different solutions of the dispersion relationship.
Inputs:
h = deep water (m)
T = wave period (s)
Outputs:
kr = wave number with Newton-Rhapson (1/m)
Lr = wavelength with Newton-Rhapson (m)
sigma = angular frequency (1/T)
Syntax :
[Lr,kr,sigma]=disper(h,T)
Example: [Lr,kr,sigma]=disper(3.05,5)
Notes:
In the command window you can see the different values which were computed, using different equations.
Referents:
Fenton,J.D and Mckee,W.D.(1990). On calculating the lengths
of water waves. Coastal Engineering 14, 499-513p.