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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)
#> Warning: data length [8000] is not a sub-multiple or multiple of the number of rows [2667]
head(result$x)
#>              X1         X2         X3
#> [1,]  2.3170769  2.8724647 -0.5008042
#> [2,]  2.6660382  1.1555344 -1.5788171
#> [3,]  0.9763068 -0.2603729  1.6418770
#> [4,] -1.8051860  1.7748163  2.3234449
#> [5,] -2.1210270  1.8700356 -0.5904800
#> [6,] -0.1671461 -0.4621430  1.9807356
head(result$y)
#> [1]   0.9217996   4.9769974   6.9813215 -27.4005703   0.8701644  -2.3295884