dr4pl (version 2.0.0)

FindInitialParms: FindInitialParms

Description

Find initial parameter estimates for a 4PL model.

Usage

FindInitialParms(
  x,
  y,
  trend = "auto",
  method.init = "Mead",
  method.robust = "squared"
)

Arguments

x

Vector of dose levels

y

Vector of responses

trend

Indicator of whether the curve is a decreasing \(\theta[3]<0\) or increasing curve \(\theta[3]>0\). See dr4pl for detailed explanation.

method.init

Method of obtaining initial values of the parameters. See dr4pl for detailed explanation.

method.robust

Parameter to select loss function for the robust estimation method to be used to fit a model. See dr4pl for detailed explanation.

Value

Initial parameter estimates of a 4PL model in the order of the upper asymptote, IC50, Slope and lower asymptote parameters.