1
|
|
|
import numpy as np |
2
|
|
|
|
3
|
|
|
from hyperactive.base import BaseExperiment |
4
|
|
|
|
5
|
|
|
|
6
|
|
|
class AckleyFunction(BaseExperiment): |
7
|
|
|
r"""Ackley function, common benchmark for optimization algorithms. |
8
|
|
|
|
9
|
|
|
The Ackley function is a non-convex function used to test optimization algorithms. |
10
|
|
|
It is defined as: |
11
|
|
|
|
12
|
|
|
.. math:: |
13
|
|
|
f(x, y) = -A \cdot \exp(-0.2 \sqrt{0.5 (x^2 + y^2)}) - \exp(0.5 (\cos(2 \pi x) + \cos(2 \pi y))) + \exp(1) + A |
14
|
|
|
|
15
|
|
|
where A is a constant. |
16
|
|
|
|
17
|
|
|
Parameters |
18
|
|
|
---------- |
19
|
|
|
A : float |
20
|
|
|
Amplitude constant used in the calculation of the Ackley function. |
21
|
|
|
|
22
|
|
|
Example |
23
|
|
|
------- |
24
|
|
|
>>> from hyperactive.experiment.toy import AckleyFunction |
25
|
|
|
>>> ackley = AckleyFunction(A=20) |
26
|
|
|
>>> params = {"x0": 1, "x1": 2} |
27
|
|
|
>>> score, add_info = ackley.score(params) |
28
|
|
|
|
29
|
|
|
Quick call without metadata return or dictionary: |
30
|
|
|
>>> score = ackley(x0=1, x1=2) |
31
|
|
|
""" # noqa: E501 |
32
|
|
|
|
33
|
|
|
_tags = { |
34
|
|
|
"property:randomness": "deterministic", # random or deterministic |
35
|
|
|
# if deterministic, two calls of score will result in the same value |
36
|
|
|
# random = two calls may result in different values; same as "stochastic" |
37
|
|
|
} |
38
|
|
|
|
39
|
|
|
def __init__(self, A): |
40
|
|
|
self.A = A |
41
|
|
|
super().__init__() |
42
|
|
|
|
43
|
|
|
def _paramnames(self): |
44
|
|
|
return ["x0", "x1"] |
45
|
|
|
|
46
|
|
View Code Duplication |
def _score(self, params): |
|
|
|
|
47
|
|
|
x = params["x0"] |
48
|
|
|
y = params["x1"] |
49
|
|
|
|
50
|
|
|
loss1 = -self.A * np.exp(-0.2 * np.sqrt(0.5 * (x * x + y * y))) |
51
|
|
|
loss2 = -np.exp(0.5 * (np.cos(2 * np.pi * x) + np.cos(2 * np.pi * y))) |
52
|
|
|
loss3 = np.exp(1) |
53
|
|
|
loss4 = self.A |
54
|
|
|
|
55
|
|
|
return -(loss1 + loss2 + loss3 + loss4), {} |
56
|
|
|
|
57
|
|
|
@classmethod |
58
|
|
|
def get_test_params(cls, parameter_set="default"): |
59
|
|
|
"""Return testing parameter settings for the skbase object. |
60
|
|
|
|
61
|
|
|
``get_test_params`` is a unified interface point to store |
62
|
|
|
parameter settings for testing purposes. This function is also |
63
|
|
|
used in ``create_test_instance`` and ``create_test_instances_and_names`` |
64
|
|
|
to construct test instances. |
65
|
|
|
|
66
|
|
|
``get_test_params`` should return a single ``dict``, or a ``list`` of ``dict``. |
67
|
|
|
|
68
|
|
|
Each ``dict`` is a parameter configuration for testing, |
69
|
|
|
and can be used to construct an "interesting" test instance. |
70
|
|
|
A call to ``cls(**params)`` should |
71
|
|
|
be valid for all dictionaries ``params`` in the return of ``get_test_params``. |
72
|
|
|
|
73
|
|
|
The ``get_test_params`` need not return fixed lists of dictionaries, |
74
|
|
|
it can also return dynamic or stochastic parameter settings. |
75
|
|
|
|
76
|
|
|
Parameters |
77
|
|
|
---------- |
78
|
|
|
parameter_set : str, default="default" |
79
|
|
|
Name of the set of test parameters to return, for use in tests. If no |
80
|
|
|
special parameters are defined for a value, will return `"default"` set. |
81
|
|
|
|
82
|
|
|
Returns |
83
|
|
|
------- |
84
|
|
|
params : dict or list of dict, default = {} |
85
|
|
|
Parameters to create testing instances of the class |
86
|
|
|
Each dict are parameters to construct an "interesting" test instance, i.e., |
87
|
|
|
`MyClass(**params)` or `MyClass(**params[i])` creates a valid test instance. |
88
|
|
|
`create_test_instance` uses the first (or only) dictionary in `params` |
89
|
|
|
""" |
90
|
|
|
return [{"A": 0}, {"A": 20}, {"A": -42}] |
91
|
|
|
|
92
|
|
|
@classmethod |
93
|
|
|
def _get_score_params(self): |
94
|
|
|
"""Return settings for the score function. |
95
|
|
|
|
96
|
|
|
Returns a list, the i-th element corresponds to self.get_test_params()[i]. |
97
|
|
|
It should be a valid call for self.score. |
98
|
|
|
|
99
|
|
|
Returns |
100
|
|
|
------- |
101
|
|
|
list of dict |
102
|
|
|
The parameters to be used for scoring. |
103
|
|
|
""" |
104
|
|
|
params0 = {"x0": 0, "x1": 0} |
105
|
|
|
params1 = {"x0": 1, "x1": 1} |
106
|
|
|
return [params0, params1] |
107
|
|
|
|