math-optim/bench/functions.go

// Copyright 2022 wanderer <a_mirre at utb dot cz>
// SPDX-License-Identifier: GPL-3.0-or-later

package bench

import "math"

var Functions = []string{"Schwefel", "De Jong 1st", "De Jong 2nd"}

// Schwefel computes a value of the Schwefel function for x.
func Schwefel(x []float64) float64 {
	var res float64

	for _, val := range x {
		res += val * math.Sin(math.Sqrt(math.Abs(val)))
	}

	return 418.9829*float64(len(x)) - res
}

// DeJong1st computes the value of the 1st De Jong function for x.
func DeJong1st(x []float64) float64 {
	var res float64

	for _, val := range x {
		res += math.Floor(val)
	}

	return res
}

// DeJong2nd computes the value of the 2nd De Jong function for x.
func DeJong2nd(x []float64) float64 {
	var res float64

	for _, val := range x {
		res += math.Pow(val, 2)
	}

	return res
}