import(nlme)
importFrom("stats", "anova", "coef", "lm", "na.omit", "nls", "nls.control", "optim", "pf", "resid", "sortedXyData")
importFrom("utils", "relist")

export(SSposnegRichards, modpar, pn.mod.compare, pn.modselect.step)
export(posnegRichards.eqn, change.pnparameters, extraF, extraF.nls)
export(get.mod)
