thursday/go_benchmark_functions/go_funcs_L.py

328 lines
9.6 KiB
Python

# -*- coding: utf-8 -*-
from numpy import sum, cos, exp, pi, arange, sin
from .go_benchmark import Benchmark
class Langermann(Benchmark):
r"""
Langermann objective function.
This class defines the Langermann [1]_ global optimization problem. This
is a multimodal minimization problem defined as follows:
.. math::
f_{\text{Langermann}}(x) = - \sum_{i=1}^{5}
\frac{c_i \cos\left\{\pi \left[\left(x_{1}- a_i\right)^{2}
+ \left(x_{2} - b_i \right)^{2}\right]\right\}}{e^{\frac{\left( x_{1}
- a_i\right)^{2} + \left( x_{2} - b_i\right)^{2}}{\pi}}}
Where:
.. math::
\begin{matrix}
a = [3, 5, 2, 1, 7]\\
b = [5, 2, 1, 4, 9]\\
c = [1, 2, 5, 2, 3] \\
\end{matrix}
Here :math:`x_i \in [0, 10]` for :math:`i = 1, 2`.
*Global optimum*: :math:`f(x) = -5.1621259`
for :math:`x = [2.00299219, 1.006096]`
.. [1] Gavana, A. Global Optimization Benchmarks and AMPGO retrieved 2015
TODO: Langermann from Gavana is _not the same_ as Jamil #68.
"""
def __init__(self, dimensions=2):
Benchmark.__init__(self, dimensions)
self._bounds = list(zip([0.0] * self.N, [10.0] * self.N))
self.global_optimum = [[2.00299219, 1.006096]]
self.fglob = -5.1621259
def fun(self, x, *args):
self.nfev += 1
a = [3, 5, 2, 1, 7]
b = [5, 2, 1, 4, 9]
c = [1, 2, 5, 2, 3]
return (-sum(c * exp(-(1 / pi) * ((x[0] - a) ** 2 +
(x[1] - b) ** 2)) * cos(pi * ((x[0] - a) ** 2
+ (x[1] - b) ** 2))))
class LennardJones(Benchmark):
r"""
LennardJones objective function.
This class defines the Lennard-Jones global optimization problem. This
is a multimodal minimization problem defined as follows:
.. math::
f_{\text{LennardJones}}(\mathbf{x}) = \sum_{i=0}^{n-2}\sum_{j>1}^{n-1}
\frac{1}{r_{ij}^{12}} - \frac{1}{r_{ij}^{6}}
Where, in this exercise:
.. math::
r_{ij} = \sqrt{(x_{3i}-x_{3j})^2 + (x_{3i+1}-x_{3j+1})^2)
+ (x_{3i+2}-x_{3j+2})^2}
Valid for any dimension, :math:`n = 3*k, k=2 , 3, 4, ..., 20`. :math:`k`
is the number of atoms in 3-D space constraints: unconstrained type:
multi-modal with one global minimum; non-separable
Value-to-reach: :math:`minima[k-2] + 0.0001`. See array of minima below;
additional minima available at the Cambridge cluster database:
http://www-wales.ch.cam.ac.uk/~jon/structures/LJ/tables.150.html
Here, :math:`n` represents the number of dimensions and
:math:`x_i \in [-4, 4]` for :math:`i = 1 ,..., n`.
*Global optimum*:
.. math::
\text{minima} = [-1.,-3.,-6.,-9.103852,-12.712062,-16.505384,\\
-19.821489, -24.113360, -28.422532,-32.765970,\\
-37.967600,-44.326801, -47.845157,-52.322627,\\
-56.815742,-61.317995, -66.530949, -72.659782,\\
-77.1777043]\\
"""
def __init__(self, dimensions=6):
# dimensions is in [6:60]
# max dimensions is going to be 60.
if dimensions not in range(6, 61):
raise ValueError("LJ dimensions must be in (6, 60)")
Benchmark.__init__(self, dimensions)
self._bounds = list(zip([-4.0] * self.N, [4.0] * self.N))
self.global_optimum = [[]]
self.minima = [-1.0, -3.0, -6.0, -9.103852, -12.712062,
-16.505384, -19.821489, -24.113360, -28.422532,
-32.765970, -37.967600, -44.326801, -47.845157,
-52.322627, -56.815742, -61.317995, -66.530949,
-72.659782, -77.1777043]
k = int(dimensions / 3)
self.fglob = self.minima[k - 2]
self.change_dimensionality = True
def change_dimensions(self, ndim):
if ndim not in range(6, 61):
raise ValueError("LJ dimensions must be in (6, 60)")
Benchmark.change_dimensions(self, ndim)
self.fglob = self.minima[int(self.N / 3) - 2]
def fun(self, x, *args):
self.nfev += 1
k = int(self.N / 3)
s = 0.0
for i in range(k - 1):
for j in range(i + 1, k):
a = 3 * i
b = 3 * j
xd = x[a] - x[b]
yd = x[a + 1] - x[b + 1]
zd = x[a + 2] - x[b + 2]
ed = xd * xd + yd * yd + zd * zd
ud = ed * ed * ed
if ed > 0.0:
s += (1.0 / ud - 2.0) / ud
return s
class Leon(Benchmark):
r"""
Leon objective function.
This class defines the Leon [1]_ global optimization problem. This
is a multimodal minimization problem defined as follows:
.. math::
f_{\text{Leon}}(\mathbf{x}) = \left(1 - x_{1}\right)^{2}
+ 100 \left(x_{2} - x_{1}^{2} \right)^{2}
with :math:`x_i \in [-1.2, 1.2]` for :math:`i = 1, 2`.
*Global optimum*: :math:`f(x) = 0` for :math:`x = [1, 1]`
.. [1] Jamil, M. & Yang, X.-S. A Literature Survey of Benchmark Functions
For Global Optimization Problems Int. Journal of Mathematical Modelling
and Numerical Optimisation, 2013, 4, 150-194.
"""
def __init__(self, dimensions=2):
Benchmark.__init__(self, dimensions)
self._bounds = list(zip([-1.2] * self.N, [1.2] * self.N))
self.global_optimum = [[1 for _ in range(self.N)]]
self.fglob = 0.0
def fun(self, x, *args):
self.nfev += 1
return 100. * (x[1] - x[0] ** 2.0) ** 2.0 + (1 - x[0]) ** 2.0
class Levy03(Benchmark):
r"""
Levy 3 objective function.
This class defines the Levy 3 [1]_ global optimization problem. This
is a multimodal minimization problem defined as follows:
.. math::
f_{\text{Levy03}}(\mathbf{x}) = \sin^2(\pi y_1)+\sum_{i=1}^{n-1}(y_i-1)^2[1+10\sin^2(\pi y_{i+1})]+(y_n-1)^2
Where, in this exercise:
.. math::
y_i=1+\frac{x_i-1}{4}
Here, :math:`n` represents the number of dimensions and :math:`x_i \in [-10, 10]` for :math:`i=1,...,n`.
*Global optimum*: :math:`f(x_i) = 0` for :math:`x_i = 1` for :math:`i=1,...,n`
.. [1] Mishra, S. Global Optimization by Differential Evolution and
Particle Swarm Methods: Evaluation on Some Benchmark Functions.
Munich Personal RePEc Archive, 2006, 1005
TODO: not clear what the Levy function definition is. Gavana, Mishra,
Adorio have different forms. Indeed Levy 3 docstring from Gavana
disagrees with the Gavana code! The following code is from the Mishra
listing of Levy08.
"""
def __init__(self, dimensions=2):
Benchmark.__init__(self, dimensions)
self._bounds = list(zip([-10.0] * self.N, [10.0] * self.N))
self.custom_bounds = [(-5, 5), (-5, 5)]
self.global_optimum = [[1 for _ in range(self.N)]]
self.fglob = 0.0
def fun(self, x, *args):
self.nfev += 1
y = 1 + (x - 1) / 4
v = sum((y[:-1] - 1) ** 2 * (1 + 10 * sin(pi * y[1:]) ** 2))
z = (y[-1] - 1) ** 2
return sin(pi * y[0]) ** 2 + v + z
class Levy05(Benchmark):
r"""
Levy 5 objective function.
This class defines the Levy 5 [1]_ global optimization problem. This
is a multimodal minimization problem defined as follows:
.. math::
f_{\text{Levy05}}(\mathbf{x}) = \sum_{i=1}^{5} i \cos \left[(i-1)x_1 + i \right] \times \sum_{j=1}^{5} j \cos \left[(j+1)x_2 + j \right] + (x_1 + 1.42513)^2 + (x_2 + 0.80032)^2
Here, :math:`n` represents the number of dimensions and :math:`x_i \in [-10, 10]` for :math:`i=1,...,n`.
*Global optimum*: :math:`f(x_i) = -176.1375779` for :math:`\mathbf{x} = [-1.30685, -1.42485]`.
.. [1] Mishra, S. Global Optimization by Differential Evolution and
Particle Swarm Methods: Evaluation on Some Benchmark Functions.
Munich Personal RePEc Archive, 2006, 1005
"""
def __init__(self, dimensions=2):
Benchmark.__init__(self, dimensions)
self._bounds = list(zip([-10.0] * self.N, [10.0] * self.N))
self.custom_bounds = ([-2.0, 2.0], [-2.0, 2.0])
self.global_optimum = [[-1.30685, -1.42485]]
self.fglob = -176.1375779
def fun(self, x, *args):
self.nfev += 1
i = arange(1, 6)
a = i * cos((i - 1) * x[0] + i)
b = i * cos((i + 1) * x[1] + i)
return sum(a) * sum(b) + (x[0] + 1.42513) ** 2 + (x[1] + 0.80032) ** 2
class Levy13(Benchmark):
r"""
Levy13 objective function.
This class defines the Levy13 [1]_ global optimization problem. This is a
multimodal minimization problem defined as follows:
.. math::
f_{\text{Levy13}}(x) = \left(x_{1} -1\right)^{2} \left[\sin^{2}
\left(3 \pi x_{2}\right) + 1\right] + \left(x_{2}
- 1\right)^{2} \left[\sin^{2}\left(2 \pi x_{2}\right)
+ 1\right] + \sin^{2}\left(3 \pi x_{1}\right)
with :math:`x_i \in [-10, 10]` for :math:`i = 1, 2`.
*Global optimum*: :math:`f(x) = 0` for :math:`x = [1, 1]`
.. [1] Mishra, S. Some new test functions for global optimization and
performance of repulsive particle swarm method.
Munich Personal RePEc Archive, 2006, 2718
"""
def __init__(self, dimensions=2):
Benchmark.__init__(self, dimensions)
self._bounds = list(zip([-10.0] * self.N, [10.0] * self.N))
self.custom_bounds = [(-5, 5), (-5, 5)]
self.global_optimum = [[1 for _ in range(self.N)]]
self.fglob = 0.0
def fun(self, x, *args):
self.nfev += 1
u = sin(3 * pi * x[0]) ** 2
v = (x[0] - 1) ** 2 * (1 + (sin(3 * pi * x[1])) ** 2)
w = (x[1] - 1) ** 2 * (1 + (sin(2 * pi * x[1])) ** 2)
return u + v + w