test_functions N-D Test Functions L

class go_benchmark.Langermann(dimensions=2)

Langermann test objective function.

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

f_{\text{Langermann}}(\mathbf{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}}}

Here, n represents the number of dimensions and x_i \in [0, 10] for i=1,2.

Langermann function

Two-dimensional Langermann function

Global optimum: f(x_i) = -5.1621259 for \mathbf{x} = [2.00299219, 1.006096]


class go_benchmark.LennardJones(dimensions=6)

LennardJones test 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:

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 go_benchmark.Leon(dimensions=2)

Leon test 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}

Here, n represents the number of dimensions and x_i \in [-1.2, 1.2] for i=1,2.

Leon function

Two-dimensional Leon function

Global optimum: f(x_i) = 0 for x_i = 1 for i=1,2


class go_benchmark.Levy03(dimensions=2)

Levy 3 test 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.

Levy 3 function

Two-dimensional Levy 3 function

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


class go_benchmark.Levy05(dimensions=2)

Levy 5 test 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.

Levy 5 function

Two-dimensional Levy 5 function

Global optimum: f(x_i) = -176.1375 for \mathbf{x} = [-1.3068, -1.4248].


class go_benchmark.Levy13(dimensions=2)

Levy13 test objective function.

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

f_{\text{Levy13}}(\mathbf{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)

Here, n represents the number of dimensions and x_i \in [-10, 10] for i=1,2.

Levy13 function

Two-dimensional Levy13 function

Global optimum: f(x_i) = 0 for x_i = 1 for i=1,2

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