def test_simulated_annealing_with_restart(self):
"""
Tests that the simulated annealing algorithm works properly when used through the
optimizer interface when using a restart.
"""
bb_obj = BBOptimizer(
black_box=self.fake_black_box_categorical,
parameter_space=np.array(
[
np.arange(-5, 5, 1),
np.arange(-6, 6, 1),
np.arange(-6, 6, 1),
np.arange(-6, 6, 1),
np.array(["tutu", "toto"])
]
).T,
heuristic="simulated_annealing",
initial_sample_size=2,
max_iteration=10,
initial_temperature=1000,
cooldown_function=multiplicative_schedule,
neighbor_function=hop_to_next_value,
cooling_factor=3,
restart=random_restart,
bernouilli_parameter=0.2,
)
bb_obj.optimize()
print(bb_obj.history["fitness"])
def test_reset(self):
"""
Tests that the "reset" method reset the attributes.
"""
bb_obj = BBOptimizer(
black_box=self.parabola,
heuristic="surrogate_model",
max_iteration=nbr_iteration,
initial_sample_size=2,
parameter_space=parameter_space,
next_parameter_strategy=expected_improvement,
regression_model=GaussianProcessRegressor,
)
bb_obj.optimize()
bb_obj.reset()
self.assertEqual(bb_obj.nbr_iteration, 0)
self.assertEqual(bb_obj.elapsed_time, 0)
self.assertEqual(bb_obj.launched, False)
self.assertDictEqual(
bb_obj.history,
{
"fitness": None,
"parameters": None,
"initialization": None,
"resampled": None,
"truncated": None,
},
)
def test_optimization_categorical(self):
"""Tests that the optimization performs correctly whenever using
a categorical variable.
"""
np.random.seed(10)
categorical_parameter_space = np.array(
[np.arange(-5, 5, 1), np.arange(-6, 6, 1),
np.arange(-6, 6, 1), ["toto", "tutu"]]
).T
bb_obj = BBOptimizer(
black_box=self.categorical_parabola,
heuristic="surrogate_model",
max_iteration=10,
initial_sample_size=2,
parameter_space=categorical_parameter_space,
next_parameter_strategy=expected_improvement,
regression_model=GaussianProcessRegressor,
)
bb_obj.optimize()
best_parameters, best_fitness = bb_obj._get_best_performance()
expected_best_parameters = np.array([0, 1, 1, "toto"], dtype=object)
expected_best_fitness = 21
np.testing.assert_array_equal(
best_parameters,
expected_best_parameters
)
self.assertEqual(best_fitness, expected_best_fitness)
def test_surrogate_model_censored_bayesian_ei(self):
"""
Tests that the optimization with regression trees and expected improvement behaves as
expected.
"""
bb_obj = BBOptimizer(
black_box=self.fake_async_black_box,
parameter_space=np.array(
[
np.arange(-5, 5, 1),
np.arange(-6, 6, 1),
np.arange(-6, 6, 1),
np.arange(-6, 6, 1),
]
).T,
heuristic="surrogate_model",
regression_model=CensoredGaussianProcesses,
next_parameter_strategy=expected_improvement,
initial_sample_size=5,
async_optim=True,
max_step_cost=1,
max_iteration=10,
max_retry=10,
)
bb_obj.optimize()
print(bb_obj.history)
def test_reevaluation(self):
"""Tests the proper implementation of the reevaluation feature.
This feature is tested by checking in the history that no re-evaluation has been done
(as is the case with this particular optimizer configuration).
With re-evaluate set to True, there are only 3 different values in the history of
parametrizations. With re-evaluate set to False, all parameters of the history are
different.
"""
nbr_iteration = 5
bb_obj = BBOptimizer(
black_box=self.parabola,
heuristic="genetic_algorithm",
max_iteration=nbr_iteration,
initial_sample_size=2,
parameter_space=parameter_space,
selection_method=tournament_pick,
crossover_method=double_point_crossover,
mutation_method=mutate_chromosome_to_neighbor,
mutation_rate=0.6,
reevaluate=False,
max_retry=5,
)
bb_obj.optimize()
self.assertEqual(
np.unique(bb_obj.history["parameters"].astype(
str), axis=0).shape[0],
7,
"Some parameter values have been evaluated several times",
)
def test_probabilistic_pick_double_crossover(self):
"""
Tests that the optimization works properly when using the tournament pick method for
selection of the fittest parents + double crossover method.
"""
bb_obj = BBOptimizer(
black_box=self.fake_black_box_categorical,
parameter_space=np.array(
[
np.arange(-5, 5, 1),
np.arange(-6, 6, 1),
np.arange(-6, 6, 1),
np.arange(-6, 6, 1),
np.array(["tutu", "toto"])
]
).T,
heuristic="genetic_algorithm",
initial_sample_size=2,
max_iteration=10,
selection_method=tournament_pick,
crossover_method=double_point_crossover,
mutation_method=mutate_chromosome_to_neighbor,
pool_size=5,
mutation_rate=0.1,
elitism=False,
)
bb_obj.optimize()
def test_summarize(self):
"""
Tests that the call to "summarize" does not raise an error.
"""
bb_obj = BBOptimizer(
black_box=self.parabola,
heuristic="surrogate_model",
max_iteration=nbr_iteration,
initial_sample_size=2,
parameter_space=parameter_space,
next_parameter_strategy=expected_improvement,
regression_model=GaussianProcessRegressor,
)
bb_obj.optimize()
bb_obj.summarize()
def test_optimizer_process_simple_resampling(self):
"""Tests that the .optimize() method works correctly when using simple resampling"""
np.random.seed(5)
bb_obj = BBOptimizer(
black_box=self.parabola,
heuristic="surrogate_model",
max_iteration=nbr_iteration,
initial_sample_size=2,
parameter_space=parameter_space,
next_parameter_strategy=expected_improvement,
regression_model=GaussianProcessRegressor,
resampling_policy="simple_resampling",
nbr_resamples=2,
)
bb_obj.optimize()
np.testing.assert_array_equal(
bb_obj.history["fitness"], np.array(
[16., 61., 61., 9., 9., 0., 0.])
)
def test_total_iteration(self):
"""
Tests that the total number of iterations is properly computed (and indirectly that the
stop criterion properly stops on the number of iterations).
"""
bb_obj = BBOptimizer(
black_box=self.parabola,
heuristic="surrogate_model",
max_iteration=nbr_iteration,
initial_sample_size=2,
parameter_space=parameter_space,
next_parameter_strategy=expected_improvement,
regression_model=GaussianProcessRegressor,
)
bb_obj.optimize()
self.assertEqual(
nbr_iteration + 2,
bb_obj.total_iteration,
"Total number of iterations " "was not computed properly.",
)
def test_exhaustive_search(self):
"""
Tests that the exhaustive search heuristic tests all the parametrization when the budget is
equal to the size of the parametric grid.
"""
parametric_grid = np.array(
[np.arange(-5, 5, 1), np.arange(-6, 6, 1), ]).T
bb_obj = BBOptimizer(
black_box=self.fake_black_box,
parameter_space=parametric_grid,
heuristic="exhaustive_search",
initial_sample_size=2,
max_iteration=120,
)
bb_obj.optimize()
exhaustive_grid = np.array(np.meshgrid(*parametric_grid)).T.reshape(
-1, len(parametric_grid)
)
np.testing.assert_array_equal(
bb_obj.history["parameters"][2:], exhaustive_grid)
def test_stop_criterion(self):
"""Tests that if the stop criterion is matched, the optimization
is stopped early and does not reach the maximum number of iterations
"""
np.random.seed(5)
bb_obj = BBOptimizer(
black_box=self.parabola,
heuristic="surrogate_model",
max_iteration=50,
initial_sample_size=2,
parameter_space=parameter_space,
next_parameter_strategy=expected_improvement,
regression_model=GaussianProcessRegressor,
stop_criterion="improvement_criterion",
stop_window=4,
improvement_estimator=min,
improvement_threshold=0.1
)
bb_obj.optimize()
self.assertTrue(len(bb_obj.history["fitness"]) < 51)
def test_optimization_callback(self):
"""Tests that the optimization step runs properly when using a custom callback.
It checks that there is the proper output in the stdout.
"""
np.random.seed(10)
captured_output = io.StringIO()
sys.stdout = captured_output
bb_obj = BBOptimizer(
black_box=self.parabola,
heuristic="surrogate_model",
max_iteration=1,
initial_sample_size=2,
parameter_space=parameter_space,
next_parameter_strategy=expected_improvement,
regression_model=GaussianProcessRegressor,
)
bb_obj.optimize(callbacks=[lambda x: print(x["fitness"][0])])
# Redirect the stdout to not mess with the system
sys.stdout = sys.__stdout__
expected = "10.0\n10.0\n10.0\n"
self.assertEqual(expected, captured_output.getvalue())
def test_surrogate_model_gp_mpi(self):
"""
Tests that the optimization process surrogate models integrates properly in the
BBOptimizer when using GP + MPI.
"""
bb_obj = BBOptimizer(
black_box=self.fake_black_box,
parameter_space=np.array(
[
np.arange(-5, 5, 1),
np.arange(-6, 6, 1),
np.arange(-6, 6, 1),
np.arange(-6, 6, 1),
]
).T,
heuristic="surrogate_model",
regression_model=GaussianProcessRegressor,
next_parameter_strategy=maximum_probability_improvement,
initial_sample_size=2,
max_iteration=10,
)
bb_obj.optimize()
def test_fitness_aggregation_optimization_process(self):
"""Tests that the optimization process happens properly when using a fitness aggregation
component.
"""
np.random.seed(5)
bb_obj = BBOptimizer(
black_box=self.parabola,
heuristic="surrogate_model",
max_iteration=nbr_iteration,
initial_sample_size=2,
parameter_space=parameter_space,
next_parameter_strategy=expected_improvement,
regression_model=GaussianProcessRegressor,
resampling_policy="simple_resampling",
nbr_resamples=5,
fitness_aggregation="simple_fitness_aggregation",
estimator=np.median,
)
bb_obj.optimize()
np.testing.assert_array_equal(
bb_obj.history["fitness"],
np.array([16.0, 61.0, 61.0, 61.0, 61.0, 61.0, 9.0]),
)
def test_surrogate_model_gp_ei(self):
"""
Tests that the optimization process surrogate models integrates properly in the
BBOptimizer when using GP + EI.
"""
bb_obj = BBOptimizer(
black_box=self.fake_black_box_categorical,
parameter_space=np.array(
[
np.arange(-5, 5, 1),
np.arange(-6, 6, 1),
np.arange(-6, 6, 1),
np.arange(-6, 6, 1),
np.array(["tutu", "toto"])
]
).T,
heuristic="surrogate_model",
regression_model=GaussianProcessRegressor,
next_parameter_strategy=expected_improvement,
initial_sample_size=2,
max_iteration=10,
)
bb_obj.optimize()
def test_surrogate_model_regression_tree_ei(self):
"""
Tests that the optimization with regression trees and expected improvement behaves as
expected.
"""
bb_obj = BBOptimizer(
black_box=self.fake_black_box,
parameter_space=np.array(
[
np.arange(-5, 5, 1),
np.arange(-6, 6, 1),
np.arange(-6, 6, 1),
np.arange(-6, 6, 1),
]
).T,
heuristic="surrogate_model",
regression_model=DecisionTreeSTDRegressor,
next_parameter_strategy=expected_improvement,
initial_sample_size=5,
max_iteration=10,
max_retry=10,
)
bb_obj.optimize()
print(bb_obj.history)
class SHAManExperiment:
"""This class represents an optimization experiment.
It allows to plan, launch and store the information corresponding to
an experiment.
"""
def __init__(
self,
component_name: str,
nbr_iteration: int,
sbatch_file: str,
experiment_name: str,
configuration_file: str,
sbatch_dir: str = None,
slurm_dir: str = None,
result_file: str = None,
) -> None:
"""Builds an object of class SHAManExperiment. This experiment is
defined by giving:
- The name of the component to tune.
- The number of allowed iterations for the optimization process.
- The name of the sbatch file to run.
- The name of the experiment.
- A configuration file to setup the experiment.
- Where the slurm outputs should be stored
(optional, if not specified, the outputs are deleted)
- The path to the result file (optional, if not specified,
no file is created).
Args:
component_name (str): The name of the component to use.
nbr_iteration (int): The number of iterations.
sbatch_file (str): The path to the sbatch file.
experiment_name (str): The name of the experiment.
sbatch_dir (str or Path): The working directory,
where the shaman sbatch will be stored.
If not specified, the directory where the command is called.
slurm_dir (str or Path): The directory where the slurm outputs
will be stored.
If set to None, all the slurm outputs are removed after the
end of the experiment.
result_file (str): The path to the result file.
If set to None, no such file is created and the results are
debuged to the screen.
configuration_file (str): The path to the configuration file.
Defaults to the configuration file present in the package
and called config.cfg.
"""
# The name of the component that will be tuned through the experiment
self.component_name = component_name
# The maximum number of iterations
self.nbr_iteration = nbr_iteration
# The name of the sbatch to use, after ensuring its existence
if Path(sbatch_file).exists():
self.sbatch_file = sbatch_file
else:
raise FileNotFoundError(f"Could not find sbatch {sbatch_file}.")
# Store information about the experiment
self.experiment_name = experiment_name
# Store the sbatch directory and convert to Path if not already
if sbatch_dir:
if isinstance(sbatch_dir, Path):
self.sbatch_dir = sbatch_dir
else:
self.sbatch_dir = Path(sbatch_dir)
else:
self.sbatch_dir = Path.cwd()
# Store the slurm directory and convert to Path if not already
if slurm_dir:
if isinstance(slurm_dir, Path):
self.slurm_dir = slurm_dir
else:
self.slurm_dir = Path(slurm_dir)
else:
self.slurm_dir = None
self.result_file = result_file
self.experiment_id = ""
# Parse the configuration
self.configuration = SHAManConfig.from_yaml(
configuration_file, self.component_name
)
# Create API client using the configuration information
self.api_client = Client(base_url=self.api_url, proxies={})
# Create the black box object using the informations
self.bb_wrapper = BBWrapper(
self.component_name,
self.configuration.component_parameter_names,
self.sbatch_file,
sbatch_dir=self.sbatch_dir,
component_configuration=self.api_url
+ "/"
+ api_settings.component_endpoint,
)
logger.debug(self.api_url + "/" + api_settings.component_endpoint)
# Setup black box optimizer using configuration information
self.bb_optimizer = self.setup_bb_optimizer()
# Compute the start of the experiment
self.experiment_start = \
datetime.datetime.utcnow().strftime("%y/%m/%d %H:%M:%S")
def setup_bb_optimizer(self) -> BBOptimizer:
"""Setups the black-box from the configuration."""
# Create the BBOptimizer object using the different options in the
# configuration
# If pruning is enabled, parse corresponding fields
if self.configuration.pruning:
pruning = True
max_step_cost = (
self.bb_wrapper.default_target_value
if self.configuration.pruning.max_step_duration == "default"
else self.configuration.pruning.max_step_duration
)
else:
max_step_cost = None
pruning = False
self.bb_optimizer = BBOptimizer(
black_box=self.bb_wrapper,
parameter_space=self.configuration.component_parameter_space,
max_iteration=self.nbr_iteration,
async_optim=pruning,
max_step_cost=max_step_cost,
**self.configuration.bbo_parameters,
)
return self.bb_optimizer
def launch(self) -> None:
"""Launches the tuning experiment."""
logger.debug("Creating experiment.")
# Create the experiment through API request
self.create_experiment()
if self.configuration.experiment.default_first:
# Launch a run using default parameterization of the component
logger.info("Running application with default parametrization.")
self.bb_wrapper.run_default()
# Setup the optimizer
logger.debug("Initializing black box optimizer.")
self.setup_bb_optimizer()
# Launch the optimization
logger.debug("Launching optimization.")
self.bb_optimizer.optimize(callbacks=[self.update_history])
# Summarize the optimization
# If there is a result file, write the output in it
if self.result_file:
orig_stdout = sys.stdout
file_ = open(self.result_file, "w")
sys.stdout = file_
self.summarize()
sys.stdout = orig_stdout
file_.close()
logger.debug(f"Summary of experiment: {self.summarize()}")
def clean(self) -> None:
"""Cleans the experiment by removing the sbatch generated by Shaman.
If there is no value specified for the slurm outputs folder,
removes them.
"""
for file_ in Path(__CURRENT_DIR__).glob("slurm*.out"):
if self.slurm_dir:
# Create if it doesn't already exist the folder
self.slurm_dir.mkdir(exist_ok=True)
# Move the output
file_.rename(self.slurm_dir / file_.name)
else:
# Remove the output
file_.unlink()
# Clean up the sbatch file in the current dir where the experiment runs
# Else keep it
for file_ in Path(__CURRENT_DIR__).glob("*_shaman*.sbatch"):
(Path(__CURRENT_DIR__) / file_).unlink()
@property
def api_url(self) -> str:
"""Returns as a string the URL to the API using the data in the
configuration file."""
return f"http://{api_settings.api_host}:{api_settings.api_port}"
@property
def start_experiment_dict(self) -> Dict:
"""Creates a dictionnary describing the experiment from its start."""
return InitExperiment(
**{
"experiment_name": self.experiment_name,
"experiment_start": self.experiment_start,
"experiment_budget": self.nbr_iteration,
"component": self.component_name,
"experiment_parameters": dict(self.configuration.bbo),
"noise_reduction_strategy":
dict(self.configuration.noise_reduction)
if self.configuration.noise_reduction
else dict(),
"pruning_strategy": {
"pruning_strategy": str(
self.configuration.pruning.max_step_duration
)
if self.configuration.pruning
else self.configuration.pruning
},
"sbatch": open(self.sbatch_file, "r").read(),
}
).dict()
def create_experiment(self) -> None:
"""Create the experiment upon initialization."""
request = self.api_client.post(
"experiments", json=self.start_experiment_dict)
if not 200 <= request.status_code < 400:
raise Exception(
"Could not create experiment with status code"
f"{request.status_code}"
)
self.experiment_id = request.json()["id"]
@property
def best_performance(self) -> float:
"""Returns the current best performance.
Returns:
float: The best time.
"""
return self.bb_optimizer._get_best_performance()
@property
def improvement_default(self) -> float:
"""Computes the improvement compared to the default parametrization.
Returns:
float: The improvement compared to the default parametrization.
"""
_, best_time = self.best_performance
return float(
round(
(self.bb_wrapper.default_target_value - best_time)
/ self.bb_wrapper.default_target_value,
2,
)
* 100
)
@property
def average_noise(self) -> float:
"""Computes the average noise within the tested parametrization.
Returns:
float: The average measured noise.
"""
return float(np.mean(self.bb_optimizer.measured_noise))
def _updated_dict(self, history: Dict) -> Dict:
"""Builds the updated dictionary that will be sent at each iteration to
the API.
Args:
history (Dict): The BBO history from the optimizer
Returns:
Dict: The updated dict to add to the POST request.
"""
logger.debug(f"Current optimization history: {history}")
best_parameters, best_fitness = self.best_performance
logger.debug(f"Best parameters so far: {best_parameters}")
logger.debug(f"Best performance so far: {best_fitness}")
return IntermediateResult(
**{
"jobids": self.bb_wrapper.component.submitted_jobids[-1],
"fitness": list(history["fitness"])[-1],
"parameters": self.build_parameter_dict(
self.configuration.component_parameter_names,
history["parameters"].tolist(),
)[-1],
"truncated": bool(list(history["truncated"])[-1]),
"resampled": bool(list(history["resampled"])[-1]),
"initialization": bool(list(history["initialization"])[-1]),
"improvement_default": self.improvement_default,
"average_noise": self.average_noise,
"explored_space":
float(self.bb_optimizer.size_explored_space[0]),
"best_parameters": self.build_parameter_dict(
self.configuration.component_parameter_names,
best_parameters.tolist(),
),
"best_fitness": best_fitness,
}
).dict()
def update_history(self, history: Dict) -> None:
"""Update the optimization history at each BBO step and force
conversion from numpy types.
Args:
history (dict): The BBO history
"""
logger.debug(
f"Writing update dictionary {self._updated_dict(history)}")
request = self.api_client.put(
f"experiments/{self.experiment_id}/update",
json=self._updated_dict(history)
)
if not 200 <= request.status_code < 400:
self.fail()
raise Exception(
"Could not finish experiment with status code"
f"{request.status_code}"
)
@property
def end_dict(self) -> Dict:
"""Comptues the dictionary sent to the API at the end of the
experiment.
Returns:
Dict: The dictionary to send to the API.
"""
best_parameters, best_fitness = self.best_performance
return FinalResult(
**{
"averaged_fitness": self.bb_optimizer.averaged_fitness,
"min_fitness": self.bb_optimizer.min_fitness,
"max_fitness": self.bb_optimizer.max_fitness,
"std_fitness": self.bb_optimizer.measured_noise,
"resampled_nbr": self.bb_optimizer.resampled_nbr,
"improvement_default": self.improvement_default,
"elapsed_time": self.bb_optimizer.elapsed_time,
"default_run": {
"fitness": self.bb_wrapper.default_target_value,
"job_id": self.bb_wrapper.default_jobid,
"parameters": self.bb_wrapper.default_parameters,
},
"average_noise": self.average_noise,
"explored_space":
float(self.bb_optimizer.size_explored_space[0]),
"best_fitness": best_fitness,
"best_parameters": self.build_parameter_dict(
self.configuration.component_parameter_names,
best_parameters.tolist(),
),
}
).dict()
def end(self):
"""End the experiment once it is over."""
request = self.api_client.put(
f"experiments/{self.experiment_id}/finish", json=self.end_dict
)
if not 200 <= request.status_code < 400:
self.fail()
raise Exception(
"Could not finish experiment with status code"
f"{request.status_code}"
)
def fail(self):
"""Fail the experiment.
If there is an experiment id, sends a request at the endpoint
/fail. Else, does not do anything (could be a good idea to
perform some logging).
"""
if self.experiment_id:
request = self.api_client.put(
f"experiments/{self.experiment_id}/fail")
if not 200 <= request.status_code < 400:
raise Exception(
"Could not fail experiment with status code"
f"{request.status_code}"
)
def stop(self):
"""Stop the experiment."""
request = self.api_client.put(f"experiments/{self.experiment_id}/stop")
if not 200 <= request.status_code < 400:
raise Exception(
"Could not fail experiment with status code"
f"{request.status_code}"
)
def summarize(self):
"""Summarize the experiment by printing out the best parametrization,
the associated fitness, and the BBO summary."""
# Compute the optimal parametrization from the bb optimizer object
optimal_param = self.build_parameter_dict(
self.configuration.component_parameter_names,
[self.bb_optimizer.best_parameters_in_grid],
)
print(f"Optimal time: {self.bb_optimizer.best_fitness}")
print(
f"Improvement compared to default:" f"{self.improvement_default}%")
print(f"Optimal parametrization: {optimal_param}")
print(
"Number of early stops:"
f"{sum(self.bb_optimizer.history['truncated'])}")
print(
"Average noise within each parametrization:"
f"{self.bb_optimizer.measured_noise}"
)
self.bb_optimizer.summarize()
@staticmethod
def build_parameter_dict(
parameter_names: List[str], parameter_values: List[List[float]]
) -> List[Dict]:
"""Static method to build the dictionary associated with the name of
the parameters and their associated values.
Args:
parameter_names (list of str): The name of the parameters to use.
parameter_values (list of lists of float):
The values of the parameters
Returns:
list of dict: the dicts of the parameters with
corresponding values.
"""
# The list that will contain the dictionaries
list_dict = []
# Check if there is at least two nested elements in the dictionary
if not isinstance(parameter_values[0], list):
parameter_values = [parameter_values]
for value in parameter_values:
list_dict.append(dict(zip(parameter_names, value)))
return list_dict