def test_lhc_criterion(self):
with self.assertRaises(ValueError) as err:
LatinHypercubeGenerator(criterion='foo')
self.assertEqual(str(err.exception),
"Invalid criterion 'foo' specified for LatinHypercubeGenerator. "
"Must be one of ['center', 'c', 'maximin', 'm', 'centermaximin', "
"'cm', 'correlation', 'corr', None].")
def test_latin_hypercube_center(self):
samples = 4
upper = 10.
prob = Problem()
model = prob.model
indep = model.add_subsystem('indep', IndepVarComp())
indep.add_output('x', 0.0)
indep.add_output('y', 0.0)
model.add_subsystem('comp', Paraboloid())
model.connect('indep.x', 'comp.x')
model.connect('indep.y', 'comp.y')
model.add_design_var('indep.x', lower=0., upper=upper)
model.add_design_var('indep.y', lower=0., upper=upper)
model.add_objective('comp.f_xy')
prob.driver = DOEDriver(LatinHypercubeGenerator(samples=samples, criterion='c'))
prob.driver.add_recorder(SqliteRecorder("CASES.db"))
prob.setup(check=False)
prob.run_driver()
prob.cleanup()
cases = CaseReader("CASES.db").driver_cases
self.assertEqual(cases.num_cases, samples)
# the sample space for each variable (0 to upper) should be divided into
# equal size buckets and each variable should have a value in each bucket
bucket_size = upper/samples
all_buckets = set(range(samples))
x_buckets_filled = set()
y_buckets_filled = set()
# with criterion of 'center', each value should be in the center of it's bucket
valid_values = [round(bucket_size*(bucket + 1/2), 3) for bucket in all_buckets]
for n in range(cases.num_cases):
x = float(cases.get_case(n).outputs['indep.x'])
y = float(cases.get_case(n).outputs['indep.y'])
x_buckets_filled.add(int(x/bucket_size))
y_buckets_filled.add(int(y/bucket_size))
self.assertTrue(round(x, 3) in valid_values, '%f not in %s' % (x, valid_values))
self.assertTrue(round(y, 3) in valid_values, '%f not in %s' % (y, valid_values))
self.assertEqual(x_buckets_filled, all_buckets)
self.assertEqual(y_buckets_filled, all_buckets)
def test_latin_hypercube_array(self):
samples = 4
bounds = np.array([
[-10, -50], # lower bounds for x and y
[10, 50] # upper bounds for x and y
])
prob = Problem()
model = prob.model
model.add_subsystem('p1',
IndepVarComp('xy', np.array([50., 50.])),
promotes=['*'])
model.add_subsystem('comp', ParaboloidArray(), promotes=['*'])
model.add_design_var('xy', lower=bounds[0], upper=bounds[1])
model.add_objective('f_xy')
prob.driver = DOEDriver(LatinHypercubeGenerator(samples=4, seed=0))
prob.driver.add_recorder(SqliteRecorder("cases.sql"))
prob.setup(check=False)
prob.run_driver()
prob.cleanup()
# the sample space for each variable should be divided into equal
# size buckets and each variable should have a value in each bucket
all_buckets = set(range(samples))
xlb, xub = bounds[0][0], bounds[1][0]
x_offset = 0 - xlb
x_bucket_size = xub - xlb
x_buckets_filled = set()
ylb, yub = bounds[0][1], bounds[1][1]
y_offset = 0 - ylb
y_bucket_size = yub - ylb
y_buckets_filled = set()
# expected values for seed = 0
expected = {
0: {
'xy': np.array([-1.98618312, -32.12026584])
},
1: {
'xy': np.array([2.118274, 47.29432502])
},
2: {
'xy': np.array([7.18793606, 16.14735283])
},
3: {
'xy': np.array([-7.25593248, -11.37792043])
},
}
cases = CaseReader("cases.sql").driver_cases
self.assertEqual(cases.num_cases, 4)
for n in range(cases.num_cases):
outputs = cases.get_case(n).outputs
x = outputs['xy'][0]
y = outputs['xy'][1]
bucket = int((x + x_offset) / (x_bucket_size / samples))
x_buckets_filled.add(bucket)
bucket = int((y + y_offset) / (y_bucket_size / samples))
y_buckets_filled.add(bucket)
assert_rel_error(self, x, expected[n]['xy'][0], 1e-4)
assert_rel_error(self, y, expected[n]['xy'][1], 1e-4)
self.assertEqual(x_buckets_filled, all_buckets)
self.assertEqual(y_buckets_filled, all_buckets)
def test_latin_hypercube(self):
samples = 4
bounds = np.array([
[-1, -10], # lower bounds for x and y
[1, 10] # upper bounds for x and y
])
xlb, xub = bounds[0][0], bounds[1][0]
ylb, yub = bounds[0][1], bounds[1][1]
prob = Problem()
model = prob.model
model.add_subsystem('p1', IndepVarComp('x', 0.0), promotes=['x'])
model.add_subsystem('p2', IndepVarComp('y', 0.0), promotes=['y'])
model.add_subsystem('comp', Paraboloid(), promotes=['x', 'y', 'f_xy'])
model.add_design_var('x', lower=xlb, upper=xub)
model.add_design_var('y', lower=ylb, upper=yub)
model.add_objective('f_xy')
prob.driver = DOEDriver()
prob.driver.options['generator'] = LatinHypercubeGenerator(samples=4,
seed=0)
prob.driver.add_recorder(SqliteRecorder("cases.sql"))
prob.setup(check=False)
prob.run_driver()
prob.cleanup()
# the sample space for each variable should be divided into equal
# size buckets and each variable should have a value in each bucket
all_buckets = set(range(samples))
xlb, xub = bounds[0][0], bounds[1][0]
x_offset = 0 - xlb
x_bucket_size = xub - xlb
x_buckets_filled = set()
ylb, yub = bounds[0][1], bounds[1][1]
y_offset = 0 - ylb
y_bucket_size = yub - ylb
y_buckets_filled = set()
# expected values for seed = 0
expected = {
0: {
'x': np.array([-0.19861831]),
'y': np.array([-6.42405317])
},
1: {
'x': np.array([0.2118274]),
'y': np.array([9.458865])
},
2: {
'x': np.array([0.71879361]),
'y': np.array([3.22947057])
},
3: {
'x': np.array([-0.72559325]),
'y': np.array([-2.27558409])
},
}
cases = CaseReader("cases.sql").driver_cases
self.assertEqual(cases.num_cases, 4)
for n in range(cases.num_cases):
outputs = cases.get_case(n).outputs
x = outputs['x']
y = outputs['y']
bucket = int((x + x_offset) / (x_bucket_size / samples))
x_buckets_filled.add(bucket)
bucket = int((y + y_offset) / (y_bucket_size / samples))
y_buckets_filled.add(bucket)
assert_rel_error(self, x, expected[n]['x'], 1e-4)
assert_rel_error(self, y, expected[n]['y'], 1e-4)
self.assertEqual(x_buckets_filled, all_buckets)
self.assertEqual(y_buckets_filled, all_buckets)