R/simpExp.R

In TIMP: Fitting Separable Nonlinear Models in Spectroscopy and Microscopy

"simpExp" <-
  function(sumT, par, t, tc) {
    sumexp <- exp(-par[2] * (t - tc))
    suma <- 1
    if (length(par) > 2) {
      for (i in seq(3, length(par), by = 2)) {
        sumexp <- sumexp + (par[i] * exp(-par[i + 1] * (t - tc)))
        suma <- suma + par[i]
      }
    }
    resT <- sumT + (par[1] * (sumexp / suma))
    resT
  }