SSpower2P: Self-Starting Nls 'power2P' Regression Model

In PhDMeiwp/basicTrendline: Add Trendline and Confidence Interval of Basic Regression Models to Plot

Self-Starting Nls 'power2P' Regression Model

Description

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

Usage

SSpower2P(predictor, a, b)

Arguments

predictor	a numeric vector of values at which to evaluate the model.
a, b	The numeric parameters responsing to the exp2P model.

Author(s)

Weiping Mei [e-mail]

See Also

trendline, SSexp3P, SSpower3P, nls, selfStart

Examples

library(basicTrendline)
x<-1:5
y<-c(2,4,8,20,25)
xy<-data.frame(x,y)
getInitial(y ~ SSpower2P(x,a,b), data = xy)
## Initial values are in fact the converged values

fitpower2P <- nls(y~SSpower2P(x,a,b), data=xy)
summary(fitpower2P)

PhDMeiwp/basicTrendline documentation built on May 7, 2022, 9:38 a.m.