math-test-functions 0.5.2

A collection of non linear functions for testing optimisation algorithms
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15

//! Ackley N2 test function

use ndarray::Array1;

/// Ackley N.2 function - challenging multimodal function
/// Global minimum: f(x*)=-200 at x=(0,0)
/// Bounds: x_i in [-32, 32]
pub fn ackley_n2(x: &Array1<f64>) -> f64 {
    let x1 = x[0];
    let x2 = x[1];
    -200.0
        * (-0.02 * (x1.powi(2) + x2.powi(2)).sqrt()).exp()
        * (2.0 * std::f64::consts::PI * x1).cos()
        * (2.0 * std::f64::consts::PI * x2).cos()
}