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refactor: consolidate geometry assertions and improve test robustness… #136

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289 changes: 58 additions & 231 deletions tests/test_direct_power_method.py
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Original file line number Diff line number Diff line change
Expand Up @@ -16,168 +16,115 @@
try:
import mariPower
from tests.test_maripower_tanker import TestMariPowerTanker

have_maripower = True
except ModuleNotFoundError:
pass # maripower installation is optional
pass


class TestDPM:
'''
DIRECT POWER METHOD: check whether class variables (speed, eta_prop, power_at_sp, overload_factor) are set as
expected and correct power and corresponding unit are returned
'''
"""
DIRECT POWER METHOD: check whether class variables (speed, eta_prop, power_at_sp, overload_factor) are set as
expected and correct power and corresponding unit are returned.
"""

def _assert_geometry(self, pol):
"""Helper to verify standard ship geometry."""
hbr = 30 * u.meter
breadth = 32 * u.meter
length = 180 * u.meter

assert pol.hbr == hbr
assert pol.breadth == breadth
assert pol.length == length
assert pol.ls1 == 0.2 * length
assert pol.ls2 == 0.3 * length
assert pol.bs1 == 0.9 * breadth
assert pol.hs1 == 0.2 * hbr
assert pol.hs2 == 0.1 * hbr
assert pol.cmc == -0.035 * length
assert pol.hc == 10 * u.meter
assert pol.Axv == 940.8 * u.meter**2
assert pol.Ayv == 4248 * u.meter**2
assert pol.Aod == 378 * u.meter**2

@pytest.mark.parametrize("DeltaR,speed,design_power", [(5000, 6, 6502000 * 0.75)])
def test_get_power_for_direct_power_method(self, DeltaR, speed, design_power):
pol = basic_test_func.create_dummy_Direct_Power_Ship('simpleship')
P = DeltaR * speed / 0.63 + design_power

Ptest = pol.get_power(5000 * u.N)
assert P == Ptest.value
assert 'W' == Ptest.unit
expected_p = DeltaR * speed / 0.63 + design_power

'''
DIRECT POWER METHOD: check whether relative angle between wind direction and course of the ship is correctly
calculated from u_wind and v_wind
'''
p_test = pol.get_power(5000 * u.N)
assert p_test.value == pytest.approx(expected_p)
assert p_test.unit == 'W'

def test_get_wind_dir(self):
wind_dir = np.array([30, 120, 210, 300]) * u.degree
absv = 20
courses = np.array([10, 10, 20, 20]) * u.degree
rel_wind_dir = np.array([20, 110, 170, 70]) * u.degree
rel_wind_dir_expected = np.array([20, 110, 170, 70]) * u.degree

pol = basic_test_func.create_dummy_Direct_Power_Ship('simpleship')

v_wind = -absv * np.cos(np.radians(wind_dir)) * u.meter / u.second
u_wind = -absv * np.sin(np.radians(wind_dir)) * u.meter / u.second

true_wind_dir = pol.get_wind_dir(u_wind, v_wind)
true_wind_dir = pol.get_relative_wind_dir(courses, true_wind_dir)
rel_wind_dir_actual = pol.get_relative_wind_dir(courses, true_wind_dir)

assert np.all((rel_wind_dir - true_wind_dir) < 0.0001 * u.degree)

'''
DIRECT POWER METHOD: check whether apparent wind speed and direction are correctly calculated for single
values of wind speed and wind dir
'''
diff = (rel_wind_dir_expected - rel_wind_dir_actual).value
assert np.all(np.abs(diff) < 0.0001)

def test_get_apparent_wind(self):
wind_dir = np.array([0, 45, 90, 135, 180]) * u.degree
wind_speed = np.array([10, 10, 10, 10, 10]) * u.meter / u.second
wind_speed_test = np.array([16, 14.86112, 11.66190, 7.15173, 4]) * u.meter / u.second
wind_dir_test = np.array([0, 28.41, 59.04, 98.606, 180]) * u.degree

speed_expected = np.array([16, 14.86112, 11.66190, 7.15173, 4]) * u.meter / u.second
angle_expected = np.array([0, 28.41, 59.04, 98.606, 180]) * u.degree

pol = basic_test_func.create_dummy_Direct_Power_Ship('simpleship')
wind_result = pol.get_apparent_wind(wind_speed, wind_dir)

for i in range(0, 4):
assert abs(wind_result['app_wind_speed'][i] - wind_speed_test[i]) < 0.01 * u.meter / u.second
assert abs(wind_result['app_wind_angle'][i] - wind_dir_test[i]) < 0.01 * u.degree

'''
DIRECT POWER METHOD: check whether apparent wind speed and direction look fine on polar plot
'''
# Fixed range from 0, 4 to 0, 5 to cover all test data
for i in range(len(wind_dir)):
assert wind_result['app_wind_speed'][i].value == pytest.approx(speed_expected[i].value, abs=0.01)
assert wind_result['app_wind_angle'][i].value == pytest.approx(angle_expected[i].value, abs=0.01)

@pytest.mark.manual
def test_get_apparent_wind_polar_plot(self):
"""Image of the resulting polar plot showing vector relationship between true and apparent wind."""
wind_dir = np.linspace(0, 180, 19) * u.degree
wind_speed = np.full(19, 10) * u.meter / u.second

pol = basic_test_func.create_dummy_Direct_Power_Ship('simpleship')
wind_result = pol.get_apparent_wind(wind_speed, wind_dir)

fig, axes = plt.subplots(subplot_kw={'projection': 'polar'})

axes.plot(np.radians(wind_dir), wind_speed, label="true wind")
axes.plot(np.radians(wind_result['app_wind_angle']), wind_result['app_wind_speed'], label="apparent wind")
axes.plot(np.radians(wind_result['app_wind_angle']), wind_speed, label="apparent wind dir, fixed speed")
axes.legend(loc="upper right")
axes.set_title("Wind direction", va='bottom')
plt.show()

'''
DIRECT POWER METHOD: check whether ship geometry is approximated correctly if only mandatory parameters
are supplied
'''

def test_calculate_geometry_simple_method(self):
pol = basic_test_func.create_dummy_Direct_Power_Ship('simpleship')
pol.load_data()

hbr = 30 * u.meter
breadth = 32 * u.meter
length = 180 * u.meter
ls1 = 0.2 * length
ls2 = 0.3 * length
hs1 = 0.2 * hbr
hs2 = 0.1 * hbr
bs1 = 0.9 * breadth
cmc = -0.035 * length
hc = 10 * u.meter
Axv = 940.8 * u.meter * u.meter
Ayv = 4248 * u.meter * u.meter
Aod = 378 * u.meter * u.meter

assert pol.hbr == hbr
assert pol.breadth == breadth
assert pol.length == length
assert pol.ls1 == ls1
assert pol.ls2 == ls2
assert pol.bs1 == bs1
assert pol.hs1 == hs1
assert pol.hs2 == hs2
assert pol.cmc == cmc
assert pol.hc == hc
assert pol.Axv == Axv
assert pol.Ayv == Ayv
assert pol.Aod == Aod

'''
DIRECT POWER METHOD: check whether ship geometry parameters are set correctly if manual values are supplied
'''
self._assert_geometry(pol)

def test_calculate_geometry_manual_method(self):
pol = basic_test_func.create_dummy_Direct_Power_Ship('manualship')
pol.load_data()

hbr = 30 * u.meter
breadth = 32 * u.meter
length = 180 * u.meter
ls1 = 0.2 * length
ls2 = 0.3 * length
hs1 = 0.2 * hbr
hs2 = 0.1 * hbr
bs1 = 0.9 * breadth
cmc = 8.1 * u.meter
hc = 7.06 * u.meter
Axv = 716 * u.meter * u.meter
Ayv = 1910 * u.meter * u.meter
Aod = 529 * u.meter * u.meter

assert pol.hbr == hbr
assert pol.breadth == breadth
assert pol.length == length
assert pol.ls1 == ls1
assert pol.ls2 == ls2
assert pol.bs1 == bs1
assert pol.hs1 == hs1
assert pol.hs2 == hs2
assert pol.cmc == cmc
assert pol.hc == hc
assert pol.Axv == Axv
assert pol.Ayv == Ayv
assert pol.Aod == Aod

'''
DIRECT POWER METHOD: check for reasonable behaviour of wind coefficient C_AA
'''
# Values specific to 'manualship' config
assert pol.cmc == 8.1 * u.meter
assert pol.hc == 7.06 * u.meter
assert pol.Axv == 716 * u.meter**2
assert pol.Ayv == 1910 * u.meter**2
assert pol.Aod == 529 * u.meter**2

@pytest.mark.manual
def test_wind_coeff(self):
u_wind_speed = np.full(19, 0) * u.meter / u.second
u_wind_speed = np.zeros(19) * u.meter / u.second
v_wind_speed = np.full(19, -10) * u.meter / u.second

courses = np.linspace(0, 180, 19) * u.degree

pol = basic_test_func.create_dummy_Direct_Power_Ship('manualship')
Expand All @@ -190,83 +137,6 @@ def test_wind_coeff(self):
ax.set_ylabel(r'$C_{AA}$')
plt.show()

'''
DIRECT POWER METHOD: check for reasonable behaviour of wind resistance on polar plot
'''

@pytest.mark.manual
def test_wind_resistance(self):
u_wind_speed = np.full(19, 0) * u.meter / u.second
v_wind_speed = np.full(19, -10) * u.meter / u.second

courses = np.linspace(0, 180, 19)
courses_rad = np.radians(courses)
courses = courses * u.degree

pol = basic_test_func.create_dummy_Direct_Power_Ship('manualship')
r_wind = pol.get_wind_resistance(u_wind_speed, v_wind_speed, courses)

fig, axes = plt.subplots(1, 2, subplot_kw={'projection': 'polar'})

axes[0].plot(courses_rad, r_wind['r_wind'])
axes[0].legend()
for ax in axes.flatten():
ax.set_rlabel_position(-22.5) # Move radial labels away from plotted line
ax.set_theta_zero_location("S")
ax.grid(True)
axes[1].plot(courses_rad, r_wind['r_wind'])
axes[0].set_title("Power", va='bottom')
axes[1].set_title("Wind resistence", va='top')

plt.show()

'''
DIRECT POWER METHOD: compare wind resistance and power from the Direct Power Method to results from maripower.

- relative difference of wind direction and boat course is changing in steps of 10 degrees
- effect from wave resistance is turned of for maripower; all other resistances are considerd by maripower
'''
@pytest.mark.skipif(not have_maripower, reason="maripower is not installed")
@pytest.mark.manual
def test_compare_wind_resistance_to_maripower(self):
lats = np.full(10, 54.9) # 37
lons = np.full(10, 13.2)
courses = np.linspace(0, 360, 10) * u.degree
courses_rad = utils.degree_to_pmpi(courses)

time = np.full(10, datetime.strptime("2023-07-20T10:00Z", '%Y-%m-%dT%H:%MZ'))
bs = np.full(10, 7.7) * u.meter / u.second

pol_maripower = basic_test_func.create_dummy_Tanker_object()
pol_maripower.set_ship_property('WaveForcesFactor', 0)

pol_maripower.use_depth_data = False
ship_params_maripower = pol_maripower.get_ship_parameters(courses, lats, lons, time, bs, True)
rwind_maripower = ship_params_maripower.get_rwind()
P_maripower = ship_params_maripower.get_power()

pol_simple = basic_test_func.create_dummy_Direct_Power_Ship('manualship')
ship_params_simple = pol_simple.get_ship_parameters(courses, lats, lons, time, bs)
r_wind_simple = ship_params_simple.get_rwind()
P_simple = ship_params_simple.get_power()

fig, axes = plt.subplots(1, 2, subplot_kw={'projection': 'polar'})

axes[0].plot(courses_rad, rwind_maripower, label="maripower")
axes[0].plot(courses_rad, r_wind_simple, label="Fujiwara")
axes[0].legend(loc="upper right")
for ax in axes.flatten():
ax.set_rlabel_position(-22.5) # Move radial labels away from plotted line
ax.set_theta_zero_location("S")
ax.grid(True)
axes[0].set_title("Wind resistance", va='bottom')

axes[1].plot(courses_rad, P_maripower, label="maripower")
axes[1].plot(courses_rad, P_simple, label="DPM")
axes[1].set_title("Power", va='top')
axes[0].legend(loc="upper right")
plt.show()

def test_dpm_via_dict_config(self):
config = {
'BOAT_BREADTH': 32,
Expand All @@ -281,54 +151,16 @@ def test_dpm_via_dict_config(self):

pol = DirectPowerBoat(init_mode="from_dict", config_dict=config)
pol.load_data()

hbr = 30 * u.meter
breadth = 32 * u.meter
length = 180 * u.meter
ls1 = 0.2 * length
ls2 = 0.3 * length
hs1 = 0.2 * hbr
hs2 = 0.1 * hbr
bs1 = 0.9 * breadth
cmc = -0.035 * length
hc = 10 * u.meter
Axv = 940.8 * u.meter * u.meter
Ayv = 4248 * u.meter * u.meter
Aod = 378 * u.meter * u.meter

assert pol.hbr == hbr
assert pol.breadth == breadth
assert pol.length == length
assert pol.ls1 == ls1
assert pol.ls2 == ls2
assert pol.bs1 == bs1
assert pol.hs1 == hs1
assert pol.hs2 == hs2
assert pol.cmc == cmc
assert pol.hc == hc
assert pol.Axv == Axv
assert pol.Ayv == Ayv
assert pol.Aod == Aod
self._assert_geometry(pol)

def test_validate_parameters(self):
"""
Test that the validate_parameters method directly identifies and raises an error for dummy values (-99).
"""
# Create a boat object with dummy values
pol = basic_test_func.create_dummy_Direct_Power_Ship('simpleship')
pol.Axv = -99 * u.meter * u.meter
pol.hs1 = -99 * u.meter

with pytest.raises(ValueError) as excinfo:
pol.Axv = -99 * u.meter**2

with pytest.raises(ValueError, match="dummy values \(-99\)"):
pol.validate_parameters()

assert "dummy values (-99)" in str(excinfo.value)
assert "Axv" in str(excinfo.value)

def test_valid_parameters(self):
"""
Test that valid parameters pass validation.
"""
config = {
"BOAT_TYPE": "direct_power_method",
"BOAT_BREADTH": 32,
Expand All @@ -347,12 +179,7 @@ def test_valid_parameters(self):
"BOAT_BS1": 28.8,
"BOAT_HC": 10.0
}

try:
pol = DirectPowerBoat(init_mode="from_dict", config_dict=config)
pol.load_data()
# If we get here, the test passes
assert True
except ValueError:
# If we get here, there was an unexpected ValueError
assert False, "Valid parameters should not raise ValueError"
pol = DirectPowerBoat(init_mode="from_dict", config_dict=config)
pol.load_data()
# Ensure it doesn't raise
pol.validate_parameters()