R/nag-r2.R

In mattwarkentin/precogs: Risk Prediction Model Assessment

#' @title Nagelkerke's R-squared
#'
#' @param rr GLM model object
#'
#' @export

nag_r2 <- function (rr) {
  ### Nicked from CRAN's fmsb package
  ### rr is an object from glm

  n <- nrow(rr$model)
  R2 <- (1 - exp((rr$dev - rr$null)/n))/(1 - exp(-rr$null/n))
  RVAL <- list(N = n, R2 = R2)
  return(RVAL)
}