| % File src/library/stats/man/SSfol.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2017 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{SSfol} |
| \encoding{UTF-8} |
| \title{Self-Starting Nls First-order Compartment Model} |
| \usage{ |
| SSfol(Dose, input, lKe, lKa, lCl) |
| } |
| \alias{SSfol} |
| \arguments{ |
| \item{Dose}{a numeric value representing the initial dose.} |
| \item{input}{a numeric vector at which to evaluate the model.} |
| \item{lKe}{a numeric parameter representing the natural logarithm of |
| the elimination rate constant.} |
| \item{lKa}{a numeric parameter representing the natural logarithm of |
| the absorption rate constant.} |
| \item{lCl}{a numeric parameter representing the natural logarithm of |
| the clearance.} |
| } |
| \description{ |
| This \code{selfStart} model evaluates the first-order compartment |
| function and its gradient. It has an \code{initial} attribute that |
| creates initial estimates of the parameters \code{lKe}, \code{lKa}, |
| and \code{lCl}. |
| } |
| \value{ |
| a numeric vector of the same length as \code{input}, which is the |
| value of the expression |
| \preformatted{Dose * exp(lKe+lKa-lCl) * (exp(-exp(lKe)*input) - exp(-exp(lKa)*input)) |
| / (exp(lKa) - exp(lKe)) |
| } |
| |
| If all of the arguments \code{lKe}, \code{lKa}, and \code{lCl} are |
| names of objects, the gradient matrix with respect to these names is |
| attached as an attribute named \code{gradient}. |
| } |
| \author{\enc{José}{Jose} Pinheiro and Douglas Bates} |
| \seealso{\code{\link{nls}}, \code{\link{selfStart}} |
| } |
| \examples{ |
| Theoph.1 <- Theoph[ Theoph$Subject == 1, ] |
| with(Theoph.1, SSfol(Dose, Time, -2.5, 0.5, -3)) # response only |
| with(Theoph.1, local({ lKe <- -2.5; lKa <- 0.5; lCl <- -3 |
| SSfol(Dose, Time, lKe, lKa, lCl) # response _and_ gradient |
| })) |
| getInitial(conc ~ SSfol(Dose, Time, lKe, lKa, lCl), data = Theoph.1) |
| ## Initial values are in fact the converged values |
| fm1 <- nls(conc ~ SSfol(Dose, Time, lKe, lKa, lCl), data = Theoph.1) |
| summary(fm1) |
| }%% TODO: visualize model parametrization as e.g. in ./SSasymp.Rd |
| \keyword{models} |