R/skew.R

In glotaran/TIMP: Fitting Separable Nonlinear Models in Spectroscopy and Microscopy

"skew" <-
  function(numax, deltanu, b, nu, nupower = 1) {
    arg <- 1 + (2 * b * (nu - numax)) / deltanu
    res <- arg
    res[which(arg > 0)] <- exp(-log(2) * (log(arg[which(arg > 0)]) / b)^2)
    res[which(arg <= 0)] <- 0
    if (nupower != 1) {
      res <- res * nu^nupower
    }

    res
  }