enh: set default JONSWAP peak enhancement factor to 3.3 (#44)

Author: vegard-solum-4ss

docs/user_guide/standardized_spectra.rst

@@ -94,7 +94,7 @@ JONSWAP spectrum given three parameters (i.e., :math:`H_s`, :math:`T_p` and :mat
 
     hs = 3.5
     tp = 10.0
-    freq, vals = spectrum(hs, tp, gamma=2)
+    freq, vals = spectrum(hs, tp, gamma=3.3)
 
 .. note::
 

src/waveresponse/_standardized1d.py

@@ -244,7 +244,7 @@ class JONSWAP(ModifiedPiersonMoskowitz):
     OchiHubble : Ochi-Hubble (three-parameter) wave spectrum.
     """
 
-    def __call__(self, hs, tp, gamma=1, freq_hz=None):
+    def __call__(self, hs, tp, gamma=3.3, freq_hz=None):
         """
         Generate wave spectrum.
 
@@ -255,7 +255,7 @@ def __call__(self, hs, tp, gamma=1, freq_hz=None):
         tp : float
             Peak period, Tp.
         gamma : float
-            Peak enhancement factor.
+            Peak enhancement factor. Default value is 3.3.
         freq_hz : bool, optional
             Whether to return the frequencies and spectrum in terms of Hz (`True`)
             or rad/s (`False`). If `None` (default), the original units of `freq` is