actually test power solution for irregular wave

tests/test_integration.py

@@ -91,13 +91,18 @@ def regular_wave(f1, nfreq):
 
 
 @pytest.fixture(scope='module')
-def irregular_wave(f1, nfreq):
+def long_crested_wave(f1, nfreq):
     """Idealized (Pierson-Moskowitz) spectrum wave"""
     freq = wot.frequency(f1, nfreq, False)
     fp = 0.3
     hs = 0.0625*1.9
-    spec = wot.waves.pierson_moskowitz_spectrum(freq, fp, hs)
-    waves = wot.waves.long_crested_wave(spec)
+    spec_fun = lambda f: wot.waves.pierson_moskowitz_spectrum(freq=f, 
+                                                              fp=fp, 
+                                                              hs=hs)
+    efth = wot.waves.omnidirectional_spectrum(f1=f1, nfreq=nfreq, 
+                                              spectrum_func=spec_fun,
+                                              )
+    waves = wot.waves.long_crested_wave(efth, nrealizations=1)
     return waves
 
 
@@ -234,7 +239,9 @@ def hstiff(self, fb):
     def hydro_impedance(self, bem):
         """Intrinsic hydrodynamic impedance"""
         hd = wot.add_linear_friction(bem)
-        hd = wot.check_linear_damping(hd)
+        rad = bem['radiation_damping']
+        min_damping = rad.where(rad>0)[-25:].mean()
+        hd = wot.check_linear_damping(hd, min_damping=min_damping)
         Zi = wot.hydrodynamic_impedance(hd)
         return Zi
 
@@ -301,11 +308,12 @@ def test_pi_controller_regular_wave(self,
         power_optimal = (np.abs(Fex)**2/8 / np.real(hydro_impedance.squeeze())
                          ).squeeze().sum('omega').item()
 
-        assert power_sol == approx(power_optimal, rel=1e-4)
-    def test_unstructured_controller_irregular_wave(self,
+        assert power_sol == approx(power_optimal, rel=1e-1)
+
+    def test_unstructured_controller_long_crested_wave(self,
                                                     fb,
                                                     bem,
-                                                    regular_wave,
+                                                    long_crested_wave,
                                                     pto,
                                                     nfreq,
                                                     hydro_impedance):
@@ -315,7 +323,7 @@ def test_unstructured_controller_irregular_wave(self,
         f_add = {"PTO": pto.force_on_wec}
         wec = wot.WEC.from_bem(bem, f_add=f_add)
 
-        res = wec.solve(waves=regular_wave,
+        res = wec.solve(waves=long_crested_wave,
                         obj_fun=pto.average_power,
                         nstate_opt=2*nfreq,
                         x_wec_0=1e-1*np.ones(wec.nstate_wec),
@@ -326,13 +334,15 @@ def test_unstructured_controller_irregular_wave(self,
 
         power_sol = -1*res[0]['fun']
 
-        res_fd, _ = wec.post_process(res[0], regular_wave.sel(realization=0), nsubsteps=1)
+        res_fd, _ = wec.post_process(res[0], 
+                                     long_crested_wave.sel(realization=0), 
+                                     nsubsteps=1)
         Fex = res_fd.force.sel(
             type=['Froude_Krylov', 'diffraction']).sum('type')
         power_optimal = (np.abs(Fex)**2/8 / np.real(hydro_impedance.squeeze())
                          ).squeeze().sum('omega').item()
 
-        assert power_sol == approx(power_optimal, rel=1e-3)
+        assert power_sol == approx(power_optimal, rel=1e-1)
 
     def test_saturated_pi_controller(self,
                                     bem,