MATLAB function for spectral moments of a spectrum

Description

Function to find the spectral moments of a bivariate spectrum

INPUT

fx : frequency in the x direction [Hz or rad/m]
fy : frequency in the y direction [Hz or rad/m]
P : spectral energy

OUTPUT

M. : structure of spectral moments
.m00 : zeorth order spectral moment
.m01 : 1st spectral moment in y direction
.m10 : 1st spectral moment in x direction
.m02 : 2nd spectral moment in y direction
.m20 : 2nd spectral moment in x direction
.fcx : center of gravity in x direction (mean frequency)
.fcy : center of gravity in y direction (mean frequency)
.mc01 : 1st central spectral moment in y direction
.mc10 : 1st central spectral moment in x direction
.mc02 : 2nd central spectral moment in y direction
.mc20 : 2nd central spectral moment in x direction