R/euclid.r

In adamlilith/statisfactory: Statistical and Geometrical Tools

#' Euclidean distance
#'
#' Euclidian distance in one or more dimensions.
#' @param a Numeric vector.
#' @param b Numeric vector of same length as \code{a}.
#' @param na.rm Logical. If \code{TRUE}, calculation ignores \code{NA}'s in \code{a} and/or \code{b}.
#' @return Numeric.
#' @examples
#'
#' euclid(0, 5)
#' euclid(c(0, 0), c(1, 1))
#' euclid(c(0, 0, 0), c(1, 1, 1))
#'
#' @export

euclid <- compiler::cmpfun(function(a, b, na.rm=FALSE) {

	if (length(a) != length(b)) stop('Length of "a" must be same as length of "b".')
	sqrt(sum((a - b)^2, na.rm=na.rm))
	
})