R/dsdx_sigmoid_inverse.R

Defines functions dsdx_sigmoid_inverse

# Leibniz's notation for computing the curvic length on inverse Logistic Model
#
# Leibniz's notation for computing the curvic length on inverse Logistic Model
#
# expression : sqrt(1+(scal * (Asym/input^2/(Asym/input - 1)))^2)
#
# @param input numeric vector of data values
# @param parms numeric vector, parameters with given names: "Asym", "xmid",
# "scal"
# @seealso \code{\link{SSlogis}}
# @references Jose Pinheiro and Douglas Bates
# @keywords math
# @examples
#
# x <-  seq(0.1,1,length=20)
# parms <- c(Asym = 2, xmid = 0.2, scal = 0.3)
# integrate(function(x) { dsdx_sigmoid_inverse(input = x, parms = parms ) }, 
# lower = 0.1, upper = 0.5)
#
#' @importFrom stats integrate
dsdx_sigmoid_inverse <- function(input, parms) {
  .value <-
    sqrt(1 + (parms["scal"] * (parms["Asym"] / input ^ 2 / (parms["Asym"] /
                                                              input - 1))) ^ 2)
  .value
}
ropensci/DoOR.functions documentation built on Feb. 22, 2024, 9:44 a.m.