Plotting JONSWAP spectrum with unknown frequency and "guessed" frequency

Hi,

Working with the JONSWAP spectrum.

From the attached formula:

I need to plot this formula against a frequency axis, and as the frequency f is unknown in the JONSWAP formula (fp is known), MATLAB will not accept the formula with the undefined parameter.

Any suggestions?

Regards

[Jose M Medina]

Probably I didn't understand properly yr question, but I think it's easy:

    for f =fmin:deltaf:fmax
               compute S for each f and store in a matrix
    end 
    plot(f,S)

Or not? :-o

Answer 1

[Dallan Friel]

Hi,

You are meant to send a vector of frequencies to the function, i.e. a range of frequency values between say 0 and 1.5 in steps of 0.1, So it will carry out the calulation for each singular f value in the vector. (0, 0.1, 0.2, 0.3, 0.4....1.5) and output the energy density of each, you then plot the output vector against the f value vector.

Simpols

Regards,

Dallan