def _sort_configs_by_acq_value(
self,
configs: List[Configuration]) -> List[Tuple[float, Configuration]]:
"""Sort the given configurations by acquisition value
Parameters
----------
configs : list(Configuration)
Returns
-------
list: (acquisition value, Candidate solutions),
ordered by their acquisition function value
"""
acq_values = self.acquisition_function(configs)
# From here
# http://stackoverflow.com/questions/20197990/how-to-make-argsort-result-to-be-random-between-equal-values
random = self.rng.rand(len(acq_values))
# Last column is primary sort key!
indices = np.lexsort((random.flatten(), acq_values.flatten()))
# Cannot use zip here because the indices array cannot index the
# rand_configs list, because the second is a pure python list
return [(acq_values[ind][0], configs[ind]) for ind in indices[::-1]]
def _get_next_by_random_search(self, num_points=1000, _sorted=False):
"""Get candidate solutions via local search.
Parameters
----------
num_points : int, optional (default=10)
Number of local searches and returned values.
_sorted : bool, optional (default=True)
Whether to sort the candidate solutions by acquisition function
value.
Returns
-------
list : (acquisition value, Candidate solutions)
"""
if num_points > 1:
rand_configs = self.config_space.sample_configuration(
size=num_points)
else:
rand_configs = [self.config_space.sample_configuration(size=1)]
if _sorted:
imputed_rand_configs = map(ConfigSpace.util.impute_inactive_values,
rand_configs)
imputed_rand_configs = [
x.get_array() for x in imputed_rand_configs
]
imputed_rand_configs = np.array(imputed_rand_configs,
dtype=np.float64)
acq_values = self.acquisition_func(imputed_rand_configs)
# From here
# http://stackoverflow.com/questions/20197990/how-to-make-argsort-result-to-be-random-between-equal-values
random = self.rng.rand(len(acq_values))
# Last column is primary sort key!
indices = np.lexsort((random.flatten(), acq_values.flatten()))
for i in range(len(rand_configs)):
rand_configs[i].origin = 'Random Search (sorted)'
# Cannot use zip here because the indices array cannot index the
# rand_configs list, because the second is a pure python list
return [(acq_values[ind][0], rand_configs[ind])
for ind in indices[::-1]]
else:
for i in range(len(rand_configs)):
rand_configs[i].origin = 'Random Search'
return [(0, rand_configs[i]) for i in range(len(rand_configs))]