Oil {nlsmsn}

Oil palm yield

Description

Growth and yield of palm oil

Usage

data(Oil)

Format

A data frame with 19 observations of oil characteristics

Author(s)

Aldo Garay [e-mail], Marcos Prates [e-mail] and Victor Lachos [e-mail]

Source

Aldo M. Garay, Victor H. Lachos, Carlos A. Abanto-Valle (2011). "Nonlinear regression models based on scale mixture of skew-normal distributions". Journal of the Korean Stastical Society, 40, 115-124.

Examples

## Not run: 
##Load the data
data(Oil)

##Define non linear function
nlf<-function(x,betas){
resp<- betas[1]/(1 +betas[2]*exp(-betas[3]*x))
return(resp)
}

##Set the response y and covariate x
y <- Oil$y
x <- Oil$x

##Set initial values
betas <- c(37,4.81,0.78)
sigma2 <- 2.95
shape <- -2
nu <- 3

## Skew.normal regression
analysis.sn <- smsn.nl(y=y, x=x, betas=betas, sigma2=sigma2, 
                       shape = shape, nlf = nlf, criteria = TRUE, 
                       family = "Skew.normal", iter.max = 200)

## Skew.t regression
analysis.st <- smsn.nl(y=y, x=x, betas=betas, sigma2=sigma2, shape = shape, 
                       nu = nu, nlf = nlf, criteria = TRUE, 
                       family = "Skew.t", iter.max = 200)

## End(Not run)