Compute the Log Likelihood for Nonlinear Heteroscedastic Models
Computes the log likelihood for a nonlinear model with possibly non constant variance.
## S3 method for class 'nlreg' logLik(object, ...)
object |
an object inheriting from class |
... |
absorbs any additional argument. |
This is a method for the function logLik() for objects
inheriting from class nlreg.
Returns an object class logLik which is a number
with attributes nobs, npar and df
giving respectively the number of observations, the number of
parameters (regression coefficients plus variance parameters) and
the degrees of freedom in the model.
The default
print method for logLik objects is used.
library(boot)
data(calcium)
calcium.nl <- nlreg( cal ~ b0*(1-exp(-b1*time)),
start = c(b0 = 4, b1 = 0.1), data = calcium )
logLik( calcium.nl )
##
data(metsulfuron)
metsulfuron.nl <-
nlreg( log(area) ~ log( b1+(b2-b1) / (1+(dose/b4)^b3) ),
weights = ~ ( 1+dose^exp(g) )^2, data = metsulfuron,
start = c(b1 = 138, b2 = 2470, b3 = 2, b4 = 0.07, g = log(0.3)),
hoa = TRUE )
logLik( metsulfuron.nl )Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.