\name{guessCellGrowthParams}
\alias{guessCellGrowthParams}
\title{Guess growth models parameters}
\usage{
  guessCellGrowthParams(x, z, relative.height.at.lag = 0.1)
}
\arguments{
  \item{x}{\code{numeric} vector: time points}

  \item{z}{code{numeric} vector: log(OD)}

  \item{relative.height.at.lag}{\code{numeric} scalar (see
  Details)}
}
\value{
  A list with entries: \item{mu}{ \code{numeric} scalar:
  maximal growth rate parameter} \item{l}{ \code{numeric}
  scalar: time lag parameter} \item{z0}{\code{numeric}
  scalar: minimal log(OD) parameter } \item{zmax}{
  \code{numeric} scalar: maximal log(OD) parameter }
}
\description{
  Guess initial parameters values for growth models
}
\details{
  The relative.height.at.lag parameter should be close to
  the relative height of the point, where the curve reaches
  its maximal slope. If the fitting fails, try to set this
  parameter to a different value.
}
\examples{
x <- 1:1000
z <- gompertz(x, mu=0.01, l=200, z0=1, zmax=5)+rnorm(length(x),mean=0,sd=0.25)
guess <- guessCellGrowthParams(x,z,relative.height.at.lag=0.5)
fit <- nls(z~gompertz(x,mu,l,z0,zmax),start=guess)
	plot(x,z)
lines(x,predict(fit,x),lwd=2,col="red")
}
\author{
  Julien Gagneur
}