NLSstAsymptotic Fit the Asymptotic Regression Model

Description

Fits the asymptotic regression model, in the form b0 + b1*(1-exp(-exp(lrc) * x)) to the xy data. This can be used as a building block in determining starting estimates for more complicated models.

Usage

NLSstAsymptotic(xy)

Arguments

xy	a sortedXyData object

Value

A numeric value of length 3 with components labelled b0, b1, and lrc. b0 is the estimated intercept on the y-axis, b1 is the estimated difference between the asymptote and the y-intercept, and lrc is the estimated logarithm of the rate constant.

Author(s)

José Pinheiro and Douglas Bates

See Also

SSasymp

Examples

Lob.329 <- Loblolly[ Loblolly$Seed == "329", ]
print(NLSstAsymptotic(sortedXyData(expression(age),
                                   expression(height),
                                   Lob.329)), digits = 3)