R/f_rastrigin.R

In olafmersmann/soobench: Single Objective Optimization Benchmark Functions

#' Rastrigin test function generator.
#'
#' The definition used is
#'
#'   \deqn{f(x) = \displaystyle 10n + \sum_{i=1}^n \left(x_i^2 - 10 \cos\left(2\pi x_i\right)\right)}
#'
#' @param dimensions [\code{integer(1)}] Size of parameter space.
#' @return A \code{soo_function}.
#'
#' @references L. A. Rastrigin. Extremal control systems.  
#' Theoretical Foundations of Engineering Cybernetics Series. 
#' (in Russian), Nauka, Moscow, 1974.
#'
#' @export
#' @useDynLib soobench do_f_rastrigin
generate_rastrigin_function <- function(dimensions)
  soo_function(name="Rastrigin",
               id=sprintf("rastrigin-%id", dimensions),
               fun=function(x, ...) .Call(do_f_rastrigin, x),
               dimensions=dimensions,
               lower_bounds=rep(-5, dimensions),
               upper_bounds=rep(5, dimensions),
               best_par=rep(0, dimensions),
               best_value=0)

## Set attributes for soo_function_generator class.
class(generate_rastrigin_function) <- c("soo_function_generator", "function")
attr(generate_rastrigin_function, "id") <- "rastrigin"
attr(generate_rastrigin_function, "name") <- "Rastrigin test function"