N-D Test Functions X¶Xin-She Yang 1 objective function.
This class defines the Xin-She Yang 1 global optimization problem. This is a multimodal minimization problem defined as follows:

The variable 
 is a random variable
uniformly distributed in 
.
Here, 
 represents the number of dimensions and
 for 
.
Two-dimensional XinSheYang01 function
Global optimum: 
 for 
 for

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.
Xin-She Yang 2 objective function.
This class defines the Xin-She Yang 2 global optimization problem. This is a multimodal minimization problem defined as follows:

Here, 
 represents the number of dimensions and
 for 
.
Two-dimensional XinSheYang02 function
Global optimum: 
 for 
 for

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.
Xin-She Yang 3 objective function.
This class defines the Xin-She Yang 3 global optimization problem. This is a multimodal minimization problem defined as follows:

Where, in this exercise, 
 and 
.
Here, 
 represents the number of dimensions and
 for 
.
Two-dimensional XinSheYang03 function
Global optimum: 
 for 
 for

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.
Xin-She Yang 4 objective function.
This class defines the Xin-She Yang 4 global optimization problem. This is a multimodal minimization problem defined as follows:
![f_{\text{XinSheYang04}}(x) = \left[ \sum_{i=1}^{n} \sin^2(x_i)
                             - e^{-\sum_{i=1}^{n} x_i^2} \right ]
                             e^{-\sum_{i=1}^{n} \sin^2 \sqrt{ \lvert
                             x_i \rvert }}](_images/math/e41b73cebd9b4502859af84689a4bd8b588f05e0.png)
Here, 
 represents the number of dimensions and
 for 
.
Two-dimensional XinSheYang04 function
Global optimum: 
 for 
 for

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.
Xor objective function.
This class defines the Xor global optimization problem. This is a multimodal minimization problem defined as follows:
![f_{\text{Xor}}(x) = \left[ 1 + \exp \left( - \frac{x_7}{1 + \exp(-x_1 - x_2 - x_5)} - \frac{x_8}{1 + \exp(-x_3 - x_4 - x_6)} - x_9 \right ) \right ]^{-2} \\
+ \left [ 1 + \exp \left( -\frac{x_7}{1 + \exp(-x_5)} - \frac{x_8}{1 + \exp(-x_6)} - x_9 \right ) \right] ^{-2} \\
+ \left [1 - \left\{1 + \exp \left(-\frac{x_7}{1 + \exp(-x_1 - x_5)} - \frac{x_8}{1 + \exp(-x_3 - x_6)} - x_9 \right ) \right\}^{-1} \right ]^2 \\
+ \left [1 - \left\{1 + \exp \left(-\frac{x_7}{1 + \exp(-x_2 - x_5)} - \frac{x_8}{1 + \exp(-x_4 - x_6)} - x_9 \right ) \right\}^{-1} \right ]^2](_images/math/08c45d03afd2c07e32aaf5fc76da4cc184733273.png)
with 
 for 
.
Global optimum: 
 for
![x = [1, -1, 1, -1, -1, 1, 1, -1, 0.421134]](_images/math/2395d7e0482f0023c6599fbcfebc695c6ca74336.png)
Gavana, A. Global Optimization Benchmarks and AMPGO