wavespectrum2timeseries#
[Eta, t, Hm0, fp, fEta, SxxEta, a, w, Phi] = wavespectrum2timeseries(f, Sxx, fs, dispout)
Description#
Inputs#
- f
Frequency (Hz)
- Sxx
Wave power spectral density (m^2s)
- fs=2;
Sampling frequency that data are collected at in (Hz)
- dispout=’no’;
Define to display outputs or not (‘yes’: display, ‘no’: not display)
Outputs#
- Eta
Water surface level time series in (m)
- t
Time in (s)
- Hm0
Zero moment wave height (m)
- fp
Peak wave frequency (Hz), fp=1/Tp (Tp: Peak wave period (s))
- fEta
Frequency from generated time series(Hz)
- SxxEta
Power spectral density from generated time series (m^2s)
- a
Wave amplitude for for one-sided spectrum (0<fEta<fs/2) from generated time series (m)
- w
Wave angular frequency for for one-sided spectrum (0<fEta<fs/2) from generated time series (rad/s)
- Phi
Wave random phase for for one-sided spectrum (0<fEta<fs/2) from generated time series (rad)
Examples#
N=2^11; %Total number of points
fs=8; %Sampling frequency
df=fs/N; %Frequency difference
f(:,1)=[0:df:fs/2]; %Frequency vector
f(1,1)=f(2,1)/2; %Assign temporarily non-zero value to fisrt element of f to prevent division by zero
Sxx=0.016.*9.81.^2./((2.*pi).^4.*(f.^5)).*exp(-1.25.*(0.33./f).^4); %Calculating Spectrum
f(1,1)=0;
Sxx(1,1)=0;
[Eta,t,Hm0,fp,fEta,SxxEta,a,w,Phi]=wavespectrum2timeseries(f,Sxx,fs,'yes');
References#
Branlard, E. (2010). Generation of time series from a spectrum. Technical University Denmark. National Laboratory for Sustainable Energy.