SSexp3P {basicTrendline}R Documentation

Self-Starting Nls 'exp3P' Regression Model

Description

This selfStart model evaluates the exponential regression function (formula as: y=a*exp(b*x)+c). It has an initial attribute that will evaluate initial estimates of the parameters a, b, and c for a given set of data.

Usage

SSexp3P(predictor, a, b, c)

Arguments

predictor

a numeric vector of values at which to evaluate the model.

a, b, c

Three numeric parameters responsing to the exp3P model.

Author(s)

Weiping Mei meiweipingg@163.com

See Also

trendline, SSexp3P, SSpower3P, nls, selfStart

Examples

library(basicTrendline)
x<-1:5
y<-c(2,4,8,16,28)
xy<-data.frame(x,y)
getInitial(y ~ SSexp3P(x,a,b,c), data = xy)
## Initial values are in fact the converged values

fitexp3P <- nls(y~SSexp3P(x,a,b,c), data=xy)
summary(fitexp3P)


[Package basicTrendline version 2.0.5 Index]