test_functions N-D Test Functions L

class Langermann(dimensions=2)

Langermann objective function.

This class defines the Langermann global optimization problem. This is a multimodal minimization problem defined as follows:

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:

\begin{matrix}
a = [3, 5, 2, 1, 7] \\
b = [5, 2, 1, 4, 9]\\
c = [1, 2, 5, 2, 3] \\
\end{matrix}

Here x_i \in [0, 10] for i = 1, 2.

Langermann function

Two-dimensional Langermann function


Global optimum: f(x) = -5.1621259 for x = [2.00299219, 1.006096]

Gavana, A. Global Optimization Benchmarks and AMPGO

Todo

Langermann from Gavana is not the same as Jamil #68.


class LennardJones(dimensions=6)

LennardJones objective function.

This class defines the Lennard-Jones global optimization problem. This is a multimodal minimization problem defined as follows:

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:

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, n = 3*k, k=2 , 3, 4, ..., 20. k is the number of atoms in 3-D space constraints: unconstrained type: multi-modal with one global minimum; non-separable

Value-to-reach: 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, n represents the number of dimensions and x_i \in [-4, 4] for i = 1 ,..., n.

Global optimum:

\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]\\


class Leon(dimensions=2)

Leon objective function.

This class defines the Leon global optimization problem. This is a multimodal minimization problem defined as follows:

f_{\text{Leon}}(\mathbf{x}) = \left(1 - x_{1}\right)^{2}
+ 100 \left(x_{2} - x_{1}^{2} \right)^{2}

with x_i \in [-1.2, 1.2] for i = 1, 2.

Leon function

Two-dimensional Leon function


Global optimum: f(x) = 0 for x = [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.


class Levy03(dimensions=2)

Levy 3 objective function.

This class defines the Levy 3 global optimization problem. This is a multimodal minimization problem defined as follows:

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:

y_i=1+\frac{x_i-1}{4}

Here, n represents the number of dimensions and x_i \in [-10, 10] for i=1,...,n.

Levy03 function

Two-dimensional Levy03 function


Global optimum: f(x_i) = 0 for x_i = 1 for i=1,...,n

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.


class Levy05(dimensions=2)

Levy 5 objective function.

This class defines the Levy 5 global optimization problem. This is a multimodal minimization problem defined as follows:

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, n represents the number of dimensions and x_i \in [-10, 10] for i=1,...,n.

Levy05 function

Two-dimensional Levy05 function


Global optimum: f(x_i) = -176.1375779 for \mathbf{x} = [-1.30685, -1.42485].

Mishra, S. Global Optimization by Differential Evolution and Particle Swarm Methods: Evaluation on Some Benchmark Functions. Munich Personal RePEc Archive, 2006, 1005


class Levy13(dimensions=2)

Levy13 objective function.

This class defines the Levy13 global optimization problem. This is a multimodal minimization problem defined as follows:

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 x_i \in [-10, 10] for i = 1, 2.

Levy13 function

Two-dimensional Levy13 function


Global optimum: f(x) = 0 for x = [1, 1]

Mishra, S. Some new test functions for global optimization and performance of repulsive particle swarm method. Munich Personal RePEc Archive, 2006, 2718


class LunacekBiRastrigin(dimensions=2)

LunacekBiRastrigin objective function.

LunacekBiRastrigin function

Two-dimensional LunacekBiRastrigin function



class LunacekBiSphere(dimensions=2)

LunacekBiSphere objective function.

LunacekBiSphere function

Two-dimensional LunacekBiSphere function


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