Sobol G-function restricted to the first two inputs - C++ backend
Source:R/sobol4r_g_wrappers.R
sobol_g2_function.RdConvenience wrapper around sobol_g_function that uses
only the first two columns of X.
Usage
sobol_g2_function(X, a = c(0, 1, 4.5, 9, 99, 99, 99, 99))