R/squared_exponential_kernel.R

In dsnavega/grnnet: Generalized Regression Neural Network

#' Squared Exponential Kernel
#'
#' @author David Navega
#'
#' @param x a vector or a matrix of pre-computed euclidean distances
#' @param sigma a numeric defining the spread of the gaussian kernel
#'
#' @return evaluation values of the squared exponential kernel function
#'
squared_exponential_kernel <- function(x, sigma) {

    value <- exp(-(x  / sigma) ^ 2)

    # return
    rout <- value
    return(rout)

}