MPV (version 1.35)

p12.12: Data Set for Problem 12-12

Description

The p12.12 data frame has 18 observations on an chemical experiment. A nonlinear model relating concentration to reaction time and temperature with an additive error is proposed to fit these data.

Usage

data(p12.12)

source

Montgomery, D.C., Peck, E.A., and Vining, C.G. (2001) Introduction to Linear Regression Analysis. 3rd Edition, John Wiley and Sons.

Examples

data(p12.12)
attach(p12.12)
# fitting the linearized model 
logy.lm <- lm(I(log(y))~I(log(x1))+I(log(x2)))
summary(logy.lm)
plot(logy.lm, which=1)  # checking the residuals
# fitting the nonlinear model
y.nls <- nls(y ~ theta1*I(x1^theta2)*I(x2^theta3), start=list(theta1=.95, 
theta2=.76, theta3=.21))
 summary(y.nls)
 plot(resid(y.nls)~fitted(y.nls)) # checking the residuals