JONSWAP#

class waveresponse.JONSWAP(freq, freq_hz=False)[source]#

JONSWAP spectrum, given as:

S(w) = alpha * S_pm(w) * gamma ** b

where,

b = exp(-(w - w_p) ** 2 / (2 * sigma ** 2 * wp ** 2))

and,

  • S_pm(w) is the Pierson-Moskowitz (PM) spectrum.

  • gamma is a peak enhancement factor.

  • alpha = 1 - 0.287 * ln(gamma) is a normalizing factor.

  • sigma is the spectral width parameter (established from experimental data):

    • sigma = 0.07 for w <= wp

    • sigma = 0.09 for w > wp

  • wp = 2pi / Tp is the angular spectral peak frequency.

Parameters:

  • freq (array-like) – Sequence of frequencies to use when generating the spectrum.

  • freq_hz (bool) – Whether the provided frequencies are in rad/s (default) or Hz.

Notes

The special case gamma=1 corresponds to the modified Pierson-Moskowitz spectrum.

See also

ModifiedPiersonMoskowitz

Modified Pierson-Moskowitz wave spectrum.

OchiHubble

Ochi-Hubble (three-parameter) wave spectrum.