R/modelfunction_asymp_inverse.R

In Dahaniel/DoOR.functions: Integrating Heterogeneous Odorant Response Data into a Common Response Model: A DoOR to the Complete Olfactome

# inverse Asymptotic Model
#
# inverse Asymptotic Model
#
# expression : -log((input-Asym)/(R0-Asym))/exp(lrc)
#
# @param input numeric vector of data values
# @param parms numeric vector, parameters with given names: "Asym", "R0",
# "lrc"
# @references Jose Pinheiro and Douglas Bates
# @keywords math
# @examples
#
# x <- seq(0.1,1,length=20)
# y <- modelfunction_asymp_inverse(input = x, parms = c(Asym = 2, R0 = 0.2, lrc = 0.3) )
# plot(x,y)
#
modelfunction_asymp_inverse <- function(input, parms) {
  subfun <- function(input)
  {
    exp1  <- (input - parms["Asym"]) / (parms["R0"] - parms["Asym"])
    if (exp1[1] <= 0 | is.na(exp1[1])) {
      return(NA)
    } else {
      return(-log((input - parms["Asym"]) / (parms["R0"] - parms["Asym"])) / 
               exp(parms["lrc"]))
    }
  }
  return(vapply(input, subfun, numeric(1)))
}