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diff --git a/man/logistic.solution.Rd b/man/logistic.solution.Rd new file mode 100644 index 00000000..798e78d1 --- /dev/null +++ b/man/logistic.solution.Rd @@ -0,0 +1,68 @@ +\name{logistic.solution} +\alias{logistic.solution} +\title{ Logistic kinetics } +\description{ + Function describing exponential decline from a defined starting value, with + an increasing rate constant, supposedly caused by microbial growth +} +\usage{ +logistic.solution(t, parent.0, kmax, k0, r) +} +\arguments{ + \item{t}{ Time. } + \item{parent.0}{ Starting value for the response variable at time zero. } + \item{kmax}{ Maximum rate constant. } + \item{k0}{ Minumum rate constant effective at time zero. } + \item{r}{ Growth rate of the increase in the rate constant. } +} +\note{ + The solution of the logistic model reduces to the + \code{\link{SFO.solution}} if \code{k0} is equal to + \code{kmax}. +} +\value{ + The value of the response variable at time \code{t}. +} +\references{ + FOCUS (2014) \dQuote{Generic guidance for Estimating Persistence and + Degradation Kinetics from Environmental Fate Studies on Pesticides in EU + Registration} Report of the FOCUS Work Group on Degradation Kinetics, + Version 1.1, 18 December 2014 + \url{http://esdac.jrc.ec.europa.eu/projects/degradation-kinetics} +} +\examples{ + # Reproduce the plot on page 57 of FOCUS (2014) + plot(function(x) logistic.solution(x, 100, 0.08, 0.0001, 0.2), + from = 0, to = 100, ylim = c(0, 100), + xlab = "Time", ylab = "Residue") + plot(function(x) logistic.solution(x, 100, 0.08, 0.0001, 0.4), + from = 0, to = 100, add = TRUE, lty = 2, col = 2) + plot(function(x) logistic.solution(x, 100, 0.08, 0.0001, 0.8), + from = 0, to = 100, add = TRUE, lty = 3, col = 3) + plot(function(x) logistic.solution(x, 100, 0.08, 0.001, 0.2), + from = 0, to = 100, add = TRUE, lty = 4, col = 4) + plot(function(x) logistic.solution(x, 100, 0.08, 0.08, 0.2), + from = 0, to = 100, add = TRUE, lty = 5, col = 5) + legend("topright", inset = 0.05, + legend = paste0("k0 = ", c(0.0001, 0.0001, 0.0001, 0.001, 0.08), + ", r = ", c(0.2, 0.4, 0.8, 0.2, 0.2)), + lty = 1:5, col = 1:5) + + # Fit with synthetic data + logistic <- mkinmod(parent = mkinsub("logistic")) + + sampling_times = c(0, 1, 3, 7, 14, 28, 60, 90, 120) + parms_logistic <- c(kmax = 0.08, k0 = 0.0001, r = 0.2) + parms_logistic_optim <- c(parent_0 = 100, parms_logistic) + d_logistic <- mkinpredict(logistic, + parms_logistic, c(parent = 100), + sampling_times) + d_2_1 <- add_err(d_logistic, + sdfunc = function(x) sigma_twocomp(x, 0.5, 0.07), + n = 1, reps = 2, digits = 5, LOD = 0.1, seed = 123456)[[1]] + + m <- mkinfit("logistic", d_2_1) + plot_sep(m) + summary(m)$bpar +} +\keyword{ manip } |