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Ishigami-Homma function evaluation

Source: R/test_functions.R
ishi_homma_fun.Rd

Evaluates the Ishigami-Homma function. Input samples are drawn from a uniform distribution over \([-\pi, \pi]^3\)

Usage

ishi_homma_fun(N, A = 2, B = 1)

Arguments

N

Number of input samples to generate.

A

(default: 2) Numeric, amplitude of the second sine component .

B

(default: 1) Numeric, coefficient of the interaction term.

Value

A list with two elements:

  • x: a numeric matrix of size N x 8 containing the input samples.

  • y: a numeric vector of length N with the corresponding function outputs.

Details

The Ishigami-Homma function is defined as: $$Y = \sin(X_1) + A \cdot \sin^2(X_2) + B \cdot X_3^4 \cdot \sin(X_1)$$ where \(X_i \sim \mathcal{U}(-\pi, \pi)\).

See also

sobol_fun, gaussian_fun

Examples

result <- ishi_homma_fun(1000)
head(result$x)
#>               X1           X2         X3
#> [1,] -0.05443348 -1.061058398  0.3978556
#> [2,] -3.06827400 -1.312432673 -2.8215873
#> [3,]  1.33332317 -1.192814747 -2.7640902
#> [4,]  0.78278887 -1.297454234 -0.1415366
#> [5,] -2.19194536  0.006835429  1.5755733
#> [6,] -0.10317137  2.491888130  2.4603557
head(result$y)
#> [1]  1.468043 -2.846818 59.433922  2.559795 -5.824497 -3.144867