R: 2D test function

goldsteinPrice {DiceKriging} | R Documentation

## 2D test function

### Description

Goldstein price 2-dimensional test function.

### Usage

    goldsteinPrice(x)

### Arguments

`x` | a 2-dimensional vector specifying the location where the function is to be evaluated.

### Details

The Goldstein price function is usually defined over the domain [-2,-2] x [2, 2]. Here, the function is adapted to the domain [0,1] x [0,1]. It has 1 global minimum : x1 = c(0.5, 0.25)

### Value

A real number equal to the Goldstein price function values at `x`

### Author(s)

D. Ginsbourger, Ecole des Mines de St-Etienne.

### Examples

    n.grid <- 20
    x.grid <- y.grid <- seq(0,1,length=n.grid)
    design.grid <- expand.grid(x.grid, y.grid)
    response.grid <- apply(design.grid, 1, goldsteinPrice)
    z.grid <- matrix(response.grid, n.grid, n.grid)
    contour(x.grid, y.grid, z.grid, 40)
    x1 = c(0.5, 0.25)
    points(t(x1), pch=19, col="red")
    title("Fonction de Goldstein price")

[Package DiceKriging version 1.5.8 Index]