R/logit.R

In Petersen: Estimators for Two-Sample Capture-Recapture Studies

#' Logit and anti-logit function.
#'
#' Compute the logit or anti-logit.
#'
#'
#' @aliases logit expit
#' @param p probability between 0 and 1.
#' @param theta logit between -infinity and +infinity
#' @return Computed logit or anti-logit
#' @author C.J.Schwarz \email{cschwarz.stat.sfu.ca@@gmail.com}
#' @keywords ~misc
#' @examples
#'
#' ##---- compute the logit and its inverse
#' logitp <- logit(.3)
#' p <- expit(-.84)
#'
#' @export logit expit
#'
logit <- function(p){
  #   logit of p
  log(p/(1-p))
}



#' @rdname logit
expit <- function(theta){
  # anti logit function
  1/(1+exp(-theta))
}