def test_constant_liar_runs(strategy, surrogate, acq_func):
"""
Tests whether the optimizer runs properly during the random
initialization phase and beyond
Parameters
----------
* `strategy` [string]:
Name of the strategy to use during optimization.
* `surrogate` [scikit-optimize surrogate class]:
A class of the scikit-optimize surrogate used in Optimizer.
"""
optimizer = Optimizer(
base_estimator=surrogate(),
dimensions=[Real(-5.0, 10.0), Real(0.0, 15.0)],
acq_func=acq_func,
acq_optimizer='sampling',
random_state=0
)
# test arguments check
assert_raises(ValueError, optimizer.ask, {"strategy": "cl_maen"})
assert_raises(ValueError, optimizer.ask, {"n_points": "0"})
assert_raises(ValueError, optimizer.ask, {"n_points": 0})
for i in range(n_steps):
x = optimizer.ask(n_points=n_points, strategy=strategy)
# check if actually n_points was generated
assert_equal(len(x), n_points)
if "ps" in acq_func:
optimizer.tell(x, [[branin(v), 1.1] for v in x])
else:
optimizer.tell(x, [branin(v) for v in x])
def test_reproducible_runs(strategy, surrogate):
# two runs of the optimizer should yield exactly the same results
optimizer = Optimizer(base_estimator=surrogate(random_state=1),
dimensions=[Real(-5.0, 10.0),
Real(0.0, 15.0)],
acq_optimizer='sampling',
random_state=1)
points = []
for i in range(n_steps):
x = optimizer.ask(n_points, strategy)
points.append(x)
optimizer.tell(x, [branin(v) for v in x])
# the x's should be exaclty as they are in `points`
optimizer = Optimizer(base_estimator=surrogate(random_state=1),
dimensions=[Real(-5.0, 10.0),
Real(0.0, 15.0)],
acq_optimizer='sampling',
random_state=1)
for i in range(n_steps):
x = optimizer.ask(n_points, strategy)
assert points[i] == x
optimizer.tell(x, [branin(v) for v in x])
def check_minimizer_api(result, n_calls, n_models=None):
# assumes the result was produced on branin
assert(isinstance(result.space, Space))
if n_models is not None:
assert_equal(len(result.models), n_models)
assert_equal(len(result.x_iters), n_calls)
assert_array_equal(result.func_vals.shape, (n_calls,))
assert(isinstance(result.x, list))
assert_equal(len(result.x), 2)
assert(isinstance(result.x_iters, list))
for n in range(n_calls):
assert(isinstance(result.x_iters[n], list))
assert_equal(len(result.x_iters[n]), 2)
assert(isinstance(result.func_vals[n], float))
assert_almost_equal(result.func_vals[n], branin(result.x_iters[n]))
assert_array_equal(result.x, result.x_iters[np.argmin(result.func_vals)])
assert_almost_equal(result.fun, branin(result.x))
assert(isinstance(result.specs, dict))
assert("args" in result.specs)
assert("function" in result.specs)
def test_reproducible_runs(strategy, surrogate):
# two runs of the optimizer should yield exactly the same results
optimizer = Optimizer(
base_estimator=surrogate(random_state=1),
dimensions=[Real(-5.0, 10.0), Real(0.0, 15.0)],
acq_optimizer='sampling',
random_state=1
)
points = []
for i in range(n_steps):
x = optimizer.ask(n_points, strategy)
points.append(x)
optimizer.tell(x, [branin(v) for v in x])
# the x's should be exaclty as they are in `points`
optimizer = Optimizer(
base_estimator=surrogate(random_state=1),
dimensions=[Real(-5.0, 10.0), Real(0.0, 15.0)],
acq_optimizer='sampling',
random_state=1
)
for i in range(n_steps):
x = optimizer.ask(n_points, strategy)
assert points[i] == x
optimizer.tell(x, [branin(v) for v in x])
def check_minimizer_api(result, n_calls, n_models=None):
# assumes the result was produced on branin
assert(isinstance(result.space, Space))
if n_models is not None:
assert_equal(len(result.models), n_models)
assert_equal(len(result.x_iters), n_calls)
assert_array_equal(result.func_vals.shape, (n_calls,))
assert(isinstance(result.x, list))
assert_equal(len(result.x), 2)
assert(isinstance(result.x_iters, list))
for n in range(n_calls):
assert(isinstance(result.x_iters[n], list))
assert_equal(len(result.x_iters[n]), 2)
assert(isinstance(result.func_vals[n], float))
assert_almost_equal(result.func_vals[n], branin(result.x_iters[n]))
assert_array_equal(result.x, result.x_iters[np.argmin(result.func_vals)])
assert_almost_equal(result.fun, branin(result.x))
assert(isinstance(result.specs, dict))
assert("args" in result.specs)
assert("function" in result.specs)
def test_constant_liar_runs(strategy, surrogate, acq_func):
"""
Tests whether the optimizer runs properly during the random
initialization phase and beyond
Parameters
----------
* `strategy` [string]:
Name of the strategy to use during optimization.
* `surrogate` [scikit-optimize surrogate class]:
A class of the scikit-optimize surrogate used in Optimizer.
"""
optimizer = Optimizer(base_estimator=surrogate(),
dimensions=[Real(-5.0, 10.0),
Real(0.0, 15.0)],
acq_func=acq_func,
acq_optimizer='sampling',
random_state=0)
# test arguments check
assert_raises(ValueError, optimizer.ask, {"strategy": "cl_maen"})
assert_raises(ValueError, optimizer.ask, {"n_points": "0"})
assert_raises(ValueError, optimizer.ask, {"n_points": 0})
for i in range(n_steps):
x = optimizer.ask(n_points=n_points, strategy=strategy)
# check if actually n_points was generated
assert_equal(len(x), n_points)
if "ps" in acq_func:
optimizer.tell(x, [[branin(v), 1.1] for v in x])
else:
optimizer.tell(x, [branin(v) for v in x])
def test_same_set_of_points_ask(strategy, surrogate):
"""
For n_points not None, tests whether two consecutive calls to ask
return the same sets of points.
Parameters
----------
* `strategy` [string]:
Name of the strategy to use during optimization.
* `surrogate` [scikit-optimize surrogate class]:
A class of the scikit-optimize surrogate used in Optimizer.
"""
optimizer = Optimizer(base_estimator=surrogate(),
dimensions=[Real(-5.0, 10.0),
Real(0.0, 15.0)],
acq_optimizer='sampling',
random_state=2)
for i in range(n_steps):
xa = optimizer.ask(n_points, strategy)
xb = optimizer.ask(n_points, strategy)
optimizer.tell(xa, [branin(v) for v in xa])
assert_equal(xa, xb) # check if the sets of points generated are equal
def test_all_points_different(strategy, surrogate):
"""
Tests whether the parallel optimizer always generates
different points to evaluate.
Parameters
----------
* `strategy` [string]:
Name of the strategy to use during optimization.
* `surrogate` [scikit-optimize surrogate class]:
A class of the scikit-optimize surrogate used in Optimizer.
"""
optimizer = Optimizer(base_estimator=surrogate(),
dimensions=[Real(-5.0, 10.0),
Real(0.0, 15.0)],
acq_optimizer='sampling',
random_state=1)
tolerance = 1e-3 # distance above which points are assumed same
for i in range(n_steps):
x = optimizer.ask(n_points, strategy)
optimizer.tell(x, [branin(v) for v in x])
distances = pdist(x)
assert all(distances > tolerance)
def test_all_points_different(strategy, surrogate):
"""
Tests whether the parallel optimizer always generates
different points to evaluate.
Parameters
----------
* `strategy` [string]:
Name of the strategy to use during optimization.
* `surrogate` [scikit-optimize surrogate class]:
A class of the scikit-optimize surrogate used in Optimizer.
"""
optimizer = Optimizer(
base_estimator=surrogate(),
dimensions=[Real(-5.0, 10.0), Real(0.0, 15.0)],
acq_optimizer='sampling',
random_state=1
)
tolerance = 1e-3 # distance above which points are assumed same
for i in range(n_steps):
x = optimizer.ask(n_points, strategy)
optimizer.tell(x, [branin(v) for v in x])
distances = pdist(x)
assert all(distances > tolerance)
def test_same_set_of_points_ask(strategy, surrogate):
"""
For n_points not None, tests whether two consecutive calls to ask
return the same sets of points.
Parameters
----------
* `strategy` [string]:
Name of the strategy to use during optimization.
* `surrogate` [scikit-optimize surrogate class]:
A class of the scikit-optimize surrogate used in Optimizer.
"""
optimizer = Optimizer(
base_estimator=surrogate(),
dimensions=[Real(-5.0, 10.0), Real(0.0, 15.0)],
acq_optimizer='sampling',
random_state=2
)
for i in range(n_steps):
xa = optimizer.ask(n_points, strategy)
xb = optimizer.ask(n_points, strategy)
optimizer.tell(xa, [branin(v) for v in xa])
assert_equal(xa, xb) # check if the sets of points generated are equal
def plot_branin():
fig, ax = plt.subplots()
x1_values = np.linspace(-5, 10, 100)
x2_values = np.linspace(0, 15, 100)
x_ax, y_ax = np.meshgrid(x1_values, x2_values)
vals = np.c_[x_ax.ravel(), y_ax.ravel()]
fx = np.reshape([branin(val) for val in vals], (100, 100))
cm = ax.pcolormesh(x_ax, y_ax, fx,
norm=LogNorm(vmin=fx.min(),
vmax=fx.max()),
cmap='viridis_r')
minima = np.array([[-np.pi, 12.275], [+np.pi, 2.275], [9.42478, 2.475]])
ax.plot(minima[:, 0], minima[:, 1], "r.", markersize=14,
lw=0, label="Minima")
cb = fig.colorbar(cm)
cb.set_label("f(x)")
ax.legend(loc="best", numpoints=1)
ax.set_xlabel("$X_0$")
ax.set_xlim([-5, 10])
ax.set_ylabel("$X_1$")
ax.set_ylim([0, 15])
def test_seven_iterations():
for minimizer in MINIMIZERS:
result = gbrt_minimize(branin, [(-5.0, 10.0), (0.0, 15.0)],
n_start=3, maxiter=7, random_state=1)
assert_equal(len(result.models), 4)
assert_array_equal(result.x_iters.shape, (7, 2))
assert_array_equal(result.func_vals.shape, (7,))
assert_array_equal(result.x, result.x_iters[np.argmin(result.func_vals)])
assert_almost_equal(result.fun, branin(result.x))
def test_one_iteration():
result = gbrt_minimize(branin, [[-5, 10], [0, 15]],
maxiter=1,
random_state=1)
assert_equal(len(result.models), 0)
assert_array_equal(result.x_iters.shape, (1, 2))
assert_array_equal(result.func_vals.shape, (1, ))
assert_array_equal(result.x, result.x_iters[np.argmin(result.func_vals)])
assert_almost_equal(result.fun, branin(result.x))
def test_seven_iterations():
result = gbrt_minimize(branin, [[-5, 10], [0, 15]],
n_start=3,
maxiter=7,
random_state=1)
assert_equal(len(result.models), 4)
assert_array_equal(result.x_iters.shape, (7, 2))
assert_array_equal(result.func_vals.shape, (7, ))
assert_array_equal(result.x, result.x_iters[np.argmin(result.func_vals)])
assert_almost_equal(result.fun, branin(result.x))
def test_defaults_are_equivalent():
# check that the defaults of Optimizer reproduce the defaults of
# gp_minimize
space = [(-5., 10.), (0., 15.)]
opt = Optimizer(space, random_state=1)
for n in range(15):
x = opt.ask()
res_opt = opt.tell(x, branin(x))
res_min = gp_minimize(branin, space, n_calls=15, random_state=1)
assert res_min.space == res_opt.space
# tolerate small differences in the points sampled
assert np.allclose(res_min.x_iters, res_opt.x_iters, atol=1e-5)
assert np.allclose(res_min.x, res_opt.x, atol=1e-5)
def test_defaults_are_equivalent():
# check that the defaults of Optimizer reproduce the defaults of
# gp_minimize
space = [(-5., 10.), (0., 15.)]
opt = Optimizer(space, random_state=1)
for n in range(15):
x = opt.ask()
res_opt = opt.tell(x, branin(x))
res_min = gp_minimize(branin, space, n_calls=15, random_state=1)
assert res_min.space == res_opt.space
# tolerate small differences in the points sampled
assert np.allclose(res_min.x_iters, res_opt.x_iters, atol=1e-5)
assert np.allclose(res_min.x, res_opt.x, atol=1e-5)
def check_minimizer_api(result, n_models):
assert(isinstance(result.space, Space))
assert_equal(len(result.models), n_models)
assert_equal(len(result.x_iters), 7)
assert_array_equal(result.func_vals.shape, (7,))
assert(isinstance(result.x, list))
assert_equal(len(result.x), 2)
assert(isinstance(result.x_iters, list))
for n in range(7):
assert(isinstance(result.x_iters[n], list))
assert_equal(len(result.x_iters[n]), 2)
assert(isinstance(result.func_vals[n], float))
assert_array_equal(result.x, result.x_iters[np.argmin(result.func_vals)])
assert_almost_equal(result.fun, branin(result.x))
assert(isinstance(result.specs, dict))
assert("args" in result.specs)
assert("function" in result.specs)
def test_defaults_are_equivalent():
# check that the defaults of Optimizer reproduce the defaults of
# gp_minimize
space = [(-5., 10.), (0., 15.)]
#opt = Optimizer(space, 'ET', acq_func="EI", random_state=1)
opt = Optimizer(space, random_state=1)
for n in range(12):
x = opt.ask()
res_opt = opt.tell(x, branin(x))
#res_min = forest_minimize(branin, space, n_calls=12, random_state=1)
res_min = gp_minimize(branin, space, n_calls=12, random_state=1)
assert res_min.space == res_opt.space
# tolerate small differences in the points sampled
assert np.allclose(res_min.x_iters, res_opt.x_iters) #, atol=1e-5)
assert np.allclose(res_min.x, res_opt.x) #, atol=1e-5)
res_opt2 = opt.get_result()
assert np.allclose(res_min.x_iters, res_opt2.x_iters) # , atol=1e-5)
assert np.allclose(res_min.x, res_opt2.x) # , atol=1e-5)
def test_branin():
xstars = np.asarray([(-np.pi, 12.275), (+np.pi, 2.275), (9.42478, 2.475)])
f_at_xstars = np.asarray([branin(xstar) for xstar in xstars])
branin_min = np.array([0.397887] * xstars.shape[0])
assert_array_almost_equal(f_at_xstars, branin_min)
def test_branin():
xstars = np.asarray([(-np.pi, 12.275), (+np.pi, 2.275), (9.42478, 2.475)])
f_at_xstars = np.asarray([branin(xstar) for xstar in xstars])
branin_min = np.array([0.397887] * xstars.shape[0])
assert_array_almost_equal(f_at_xstars, branin_min)
def run(self):
from skopt.benchmarks import branin
with self.output().localize("w") as tmp:
tmp.dump({"x": self.branch_data, "y": branin(self.branch_data)})
subplot_no += 1
plt.subplot(subplot_no)
plt.pcolormesh(x_ax, y_ax, acquis_values)
plt.plot(opt_points[:, 0], opt_points[:, 1], 'wo', markersize=5)
plt.plot(best_min[0], best_min[1], 'ro', markersize=5)
plt.plot(min_x, min_y, 'go', markersize=5)
plt.colorbar()
plt.xlabel('X1')
plt.xlim([-5, 10])
plt.ylabel('X2')
plt.ylim([0, 15])
plt.title("LCB after 20 iterations.")
subplot_no += 1
plt.subplot(subplot_no)
func_values = np.reshape([branin(val) for val in vals], (100, 100))
plt.plot(opt_points[:, 0], opt_points[:, 1], 'wo', markersize=5)
plt.plot(best_min[0], best_min[1], 'ro', markersize=5)
plt.plot(min_x, min_y, 'go', markersize=5)
plt.pcolormesh(x_ax, y_ax, func_values)
plt.colorbar()
plt.xlabel('X1')
plt.xlim([-5, 10])
plt.ylabel('X2')
plt.ylim([0, 15])
plt.title("Function values")
plt.suptitle("2-D acquisition values on the branin function")
plt.show()
subplot_no += 1
plt.subplot(subplot_no)
plt.pcolormesh(x_ax, y_ax, acquis_values)
plt.plot(opt_points[:, 0], opt_points[:, 1], 'wo', markersize=5)
plt.plot(best_min[0], best_min[1], 'ro', markersize=5)
plt.plot(min_x, min_y, 'go', markersize=5)
plt.colorbar()
plt.xlabel('X1')
plt.xlim([-5, 10])
plt.ylabel('X2')
plt.ylim([0, 15])
plt.title("LCB after 20 iterations.")
subplot_no += 1
plt.subplot(subplot_no)
func_values = np.reshape([branin(val) for val in vals], (100, 100))
plt.plot(opt_points[:, 0], opt_points[:, 1], 'wo', markersize=5)
plt.plot(best_min[0], best_min[1], 'ro', markersize=5)
plt.plot(min_x, min_y, 'go', markersize=5)
plt.pcolormesh(x_ax, y_ax, func_values)
plt.colorbar()
plt.xlabel('X1')
plt.xlim([-5, 10])
plt.ylabel('X2')
plt.ylim([0, 15])
plt.title("Function values")
plt.suptitle("2-D acquisition values on the branin function")
plt.show()
