aboutsummaryrefslogtreecommitdiff
path: root/R/logistic.solution.R
diff options
context:
space:
mode:
authorJohannes Ranke <jranke@uni-bremen.de>2020-05-07 22:13:33 +0200
committerJohannes Ranke <jranke@uni-bremen.de>2020-05-07 22:14:19 +0200
commit92bd33824bde6b6b21bfc7e30953092a74d3cce5 (patch)
treebb2e08ef15d8a4f4f7b04cf4f5312ec861ec1d1c /R/logistic.solution.R
parent67c8163487e776e9a378c9dfcd39c74f6e6bc507 (diff)
Another overhaul of analytical solutions
Still in preparation for analytical solutions of coupled models
Diffstat (limited to 'R/logistic.solution.R')
-rw-r--r--R/logistic.solution.R59
1 files changed, 0 insertions, 59 deletions
diff --git a/R/logistic.solution.R b/R/logistic.solution.R
deleted file mode 100644
index d9db13d7..00000000
--- a/R/logistic.solution.R
+++ /dev/null
@@ -1,59 +0,0 @@
-#' Logistic kinetics
-#'
-#' Function describing exponential decline from a defined starting value, with
-#' an increasing rate constant, supposedly caused by microbial growth
-#'
-#' @param t Time.
-#' @param parent.0 Starting value for the response variable at time zero.
-#' @param kmax Maximum rate constant.
-#' @param k0 Minumum rate constant effective at time zero.
-#' @param r Growth rate of the increase in the rate constant.
-#' @return The value of the response variable at time \code{t}.
-#' @note The solution of the logistic model reduces to the
-#' \code{\link{SFO.solution}} if \code{k0} is equal to \code{kmax}.
-#' @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)
-#' 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, quiet = TRUE)
-#' plot_sep(m)
-#' summary(m)$bpar
-#' endpoints(m)$distimes
-#'
-#' @export
-logistic.solution <- function(t, parent.0, kmax, k0, r)
-{
- parent = parent.0 * (kmax / (kmax - k0 + k0 * exp (r * t))) ^(kmax/r)
-}

Contact - Imprint